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Sample records for boreal-grassland transition zone

  1. Molecular differences in transition zone and peripheral zone prostate tumors

    Science.gov (United States)

    Sinnott, Jennifer A.; Rider, Jennifer R.; Carlsson, Jessica; Gerke, Travis; Tyekucheva, Svitlana; Penney, Kathryn L.; Sesso, Howard D.; Loda, Massimo; Fall, Katja; Stampfer, Meir J.; Mucci, Lorelei A.; Pawitan, Yudi; Andersson, Sven-Olof; Andrén, Ove

    2015-01-01

    Prostate tumors arise primarily in the peripheral zone (PZ) of the prostate, but 20–30% arise in the transition zone (TZ). Zone of origin may have prognostic value or reflect distinct molecular subtypes; however, it can be difficult to determine in practice. Using whole-genome gene expression, we built a signature of zone using normal tissue from five individuals and found that it successfully classified nine tumors of known zone. Hypothesizing that this signature captures tumor zone of origin, we assessed its relationship with clinical factors among 369 tumors of unknown zone from radical prostatectomies (RPs) and found that tumors that molecularly resembled TZ tumors showed lower mortality (P = 0.09) that was explained by lower Gleason scores (P = 0.009). We further applied the signature to an earlier study of 88 RP and 333 transurethral resection of the prostate (TURP) tumor samples, also of unknown zone, with gene expression on ~6000 genes. We had observed previously substantial expression differences between RP and TURP specimens, and hypothesized that this might be because RPs capture primarily PZ tumors, whereas TURPs capture more TZ tumors. Our signature distinguished these two groups, with an area under the receiver operating characteristic curve of 87% (P zones. Zone of origin may be important to consider in prostate tumor biomarker research. PMID:25870172

  2. Stress relief of transition zones

    International Nuclear Information System (INIS)

    Woodward, J.; van Rooyen, D.

    1984-01-01

    This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here concentrated on the identification of an optimal, in-situ stress relief treatment

  3. Dynamics of the solar transition zone

    Science.gov (United States)

    Bruner, E. C., Jr.

    1978-01-01

    Time-resolved profiles of the 1548-A C IV line arising from the solar transition region are analyzed in order to determine whether the 300-sec oscillations characteristic of the photosphere and chromosphere penetrate into the transition zone and to measure the rms amplitude of transition-zone disturbances as well as their dependence on solar activity. The rms velocity amplitude is used to set limits on the mechanical energy flux available for solar heating. A power-spectrum analysis indicates that acoustic waves appear to have been detected in the transition zone, that at least one case of a strong 200- to 300-sec oscillation was observed, but that strong periodicities are not found on the average in either the intensity or the velocity field. It is suggested that the rms velocity that may be attributed to directly observable wave motion is between 3 and 7 km/s, depending on whether the individual emission elements seen in rocket spectra are coherent or independent in phase.

  4. The transition zone above a lumbosacral fusion.

    Science.gov (United States)

    Hambly, M F; Wiltse, L L; Raghavan, N; Schneiderman, G; Koenig, C

    1998-08-15

    The clinical and radiographic effect of a lumbar or lumbosacral fusion was studied in 42 patients who had undergone a posterolateral fusion with an average follow-up of 22.6 years. To examine the long-term effects of posterolateral lumbar or lumbosacral fusion on the cephalad two motion segments (transition zone). It is commonly held that accelerated degeneration occurs in the motion segments adjacent to a fusion. Most studies are of short-term, anecdotal, uncontrolled reports that pay particular attention only to the first motion segment immediately cephalad to the fusion. Forty-two patients who had previously undergone a posterolateral lumbar or lumbosacral fusion underwent radiographic and clinical evaluation. Rate of fusion, range of motion, osteophytes, degenerative spondylolisthesis, retrolisthesis, facet arthrosis, disc ossification, dynamic instability, and disc space height were all studied and statistically compared with an age- and gender-matched control group. The patient's self-reported clinical outcome was also recorded. Degenerative changes occurred at the second level above the fused levels with a frequency equal to those occurring in the first level. There was no statistical difference between the study group and the cohort group in the presence of radiographic changes within the transition zone. In those patients undergoing fusion for degenerative processes, 75% reported a good to excellent outcome, whereas 84% of those undergoing fusion for spondylolysis or spondylolisthesis reported a good to excellent outcome. Radiographic changes occur within the transition zone cephalad to a lumbar or lumbosacral fusion. However, these changes are also seen in control subjects who have had no surgery.

  5. Dynamics of the solar transition zone

    International Nuclear Information System (INIS)

    Bruner, E.C. Jr.

    1978-01-01

    This paper reports on the analysis of time-resolved C IV line profiles arising from the solar transition zone. Objectives were twofold: to determine whether the 300 s photospheric oscillations penetrate to the transition zone, and to measure the rms velocity disturbance amplitude and its dependence upon solar activity. The data set consisted of 44 times sequences of 50 min average duration and included samples from study experiments of both active and quiet regions of the disk. Power-spectrum analysis of the time series of intensity and line position measurements showed at least one example of a well-developed 300 s oscillation. There was no evidence, however, for 300 s peaks in the average power spectra either in the quiet network or in active regions.The rms velocities were found to be about 2.3 km s - 1 in active regions and 5.7 km s -1 in quiet regions. The suggested average value, allowing for the substantial statistical noise contribution to the quiet Sun data, is about 3 km s -1 . The inferred energy flux, assuming energy transport by acoustic waves, is at most 1.6 x 10 4 ergs cm -2 s -1 for spatial scales greater than 15,000 km and periods in the range 100--1800 s. The acoustic-wave hypothesis apparently fails by at least one order of magnitude to provide the 2--6 x 10 5 ergs cm -2 s -1 thought to be required to replace coronal energy losses. The data are, however, consistent with heating mechanisms based on energy transport by magnetohydrodynamic waves

  6. Transit Traffic Analysis Zone Delineating Method Based on Thiessen Polygon

    Directory of Open Access Journals (Sweden)

    Shuwei Wang

    2014-04-01

    Full Text Available A green transportation system composed of transit, busses and bicycles could be a significant in alleviating traffic congestion. However, the inaccuracy of current transit ridership forecasting methods is imposing a negative impact on the development of urban transit systems. Traffic Analysis Zone (TAZ delineating is a fundamental and essential step in ridership forecasting, existing delineating method in four-step models have some problems in reflecting the travel characteristics of urban transit. This paper aims to come up with a Transit Traffic Analysis Zone delineation method as supplement of traditional TAZs in transit service analysis. The deficiencies of current TAZ delineating methods were analyzed, and the requirements of Transit Traffic Analysis Zone (TTAZ were summarized. Considering these requirements, Thiessen Polygon was introduced into TTAZ delineating. In order to validate its feasibility, Beijing was then taken as an example to delineate TTAZs, followed by a spatial analysis of office buildings within a TTAZ and transit station departure passengers. Analysis result shows that the TTAZs based on Thiessen polygon could reflect the transit travel characteristic and is of in-depth research value.

  7. Tracing the influence of the Trans-European Suture Zone into the mantle transition zone

    Czech Academy of Sciences Publication Activity Database

    Knapmeyer-Endrun, B.; Krüger, F.; Legendre, C. P.; Geissler, W.H.; Plomerová, Jaroslava; Babuška, Vladislav; Gaždová, Renata; Jedlička, Petr; Kolínský, Petr; Málek, Jiří; Novotný, Oldřich; Růžek, Bohuslav

    2013-01-01

    Roč. 363, FEB 1 (2013), s. 73-87 ISSN 0012-821X Institutional support: RVO:67985530 ; RVO:67985891 Keywords : mantle transition zone * Trans-European Suture Zone * East European Craton Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 4.724, year: 2013

  8. Monitoring of transition zones in railways

    NARCIS (Netherlands)

    Coelho, B.; Priest, J.; Holscher, P.; Powrie, W.

    2009-01-01

    Transitions between railway track on embankments or natural ground and fixed structures such as bridges and culverts often require substantial additional maintenance to preserve line, level and ride quality. This extra maintenance not only increases costs but also causes delays. Despite its

  9. Water-induced convection in the Earth's mantle transition zone

    Science.gov (United States)

    Richard, Guillaume C.; Bercovici, David

    2009-01-01

    Water enters the Earth's mantle by subduction of oceanic lithosphere. Most of this water immediately returns to the atmosphere through arc volcanism, but a part of it is expected as deep as the mantle transition zone (410-660 km depth). There, slabs can be deflected and linger before sinking into the lower mantle. Because it lowers the density and viscosity of the transition zone minerals (i.e., wadsleyite and ringwoodite), water is likely to affect the dynamics of the transition zone mantle overlying stagnant slabs. The consequences of water exchange between a floating slab and the transition zone are investigated. In particular, we focus on the possible onset of small-scale convection despite the adverse thermal gradient (i.e., mantle is cooled from below by the slab). The competition between thermal and hydrous effects on the density and thus on the convective stability of the top layer of the slab is examined numerically, including water-dependent density and viscosity and temperature-dependent water solubility. For plausible initial water content in a slab (≥0.5 wt %), an episode of convection is likely to occur after a relatively short time delay (5-20 Ma) after the slab enters the transition zone. However, water induced rheological weakening is seen to be a controlling parameter for the onset time of convection. Moreover, small-scale convection above a stagnant slab greatly enhances the rate of slab dehydration. Small-scale convection also facilitates heating of the slab, which in itself may prolong the residence time of the slab in the transition zone.

  10. Significance and clinical value of the transitional zone volume (TZV ...

    African Journals Online (AJOL)

    M. El Ghoneimy

    2017-01-12

    Jan 12, 2017 ... Objective: The aim of this work was to evaluate the significance and clinical value of the TZI, which has been a point of ... Conclusion: Estimating the transition zone volume during TRUS is a reasonable way to obtain the required ... Besides the IPSS score, a complete medical and surgical history was also.

  11. Dilution in Transition Zone between Rising Plumes and Surface Plumes

    DEFF Research Database (Denmark)

    Larsen, Torben

    2004-01-01

    The papers presents some physical experiments with the dilution of sea outfall plumes with emphasize on the transition zone where the relative fast flowing vertical plume turns to a horizontal surface plume following the slow sea surface currents. The experiments show that a considerable dilution...

  12. Experimental analysis of railway track settlement in transition zones

    NARCIS (Netherlands)

    Wang, H.; Markine, V.L.; Liu, X.

    2017-01-01

    Transition zones in railway tracks are the locations with considerable changes in the vertical support structures. Due to the differential stiffness and settlement in the open track and the engineering structure resulting in the dynamic amplification of the wheel forces, track settlement is usually

  13. Mantle transition zone structure beneath the Canadian Shield

    Science.gov (United States)

    Thompson, D. A.; Helffrich, G. R.; Bastow, I. D.; Kendall, J. M.; Wookey, J.; Eaton, D. W.; Snyder, D. B.

    2010-12-01

    The Canadian Shield is underlain by one of the deepest and most laterally extensive continental roots on the planet. Seismological constraints on the mantle structure beneath the region are presently lacking due to the paucity of stations in this remote area. Presented here is a receiver function study on transition zone structure using data from recently deployed seismic networks from the Hudson Bay region. High resolution images based on high signal-to-noise ratio data show clear arrivals from the 410 km and 660 km discontinuities, revealing remarkably little variation in transition zone structure. Transition zone thickness is close to the global average (averaging 245 km across the study area), and any deviations in Pds arrival time from reference Earth models can be readily explained by upper-mantle velocity structure. The 520 km discontinuity is not a ubiquitous feature, and is only weakly observed in localised areas. These results imply that the Laurentian root is likely confined to the upper-mantle and if any mantle downwelling exists, possibly explaining the existence of Hudson Bay, it is also confined to the upper 400 km. Any thermal perturbations at transition zone depths associated with the existence of the root, whether they be cold downwellings or elevated temperatures due to the insulating effect of the root, are thus either non-existent or below the resolution of the study.

  14. Critical Transition in Critical Zone of Intensively Managed Landscapes

    Science.gov (United States)

    Kumar, P.

    2017-12-01

    Intensification of industrial agriculture has resulted in severe unintended global impacts, including degradation of arable land and eutrophication of receiving water bodies. Modern agricultural practices rely on significant direct and indirect human energy inputs, which have created imbalances between increased rates of biogeochemical processes related to production and background rates of natural processes. These imbalances have cascaded through the deep inter-dependencies between carbon, soil, water, nutrient and ecological processes, resulting in a critical transition of the Critical Zone and creating emergent dynamics and evolutionary trajectories. Understanding of these novel organization and function of the Critical Zone is vital for developing sustainable agricultural practices.

  15. Hirschsprung's disease: problems with transition-zone pull-through.

    Science.gov (United States)

    Ghose, S I; Squire, B R; Stringer, M D; Batcup, G; Crabbe, D C

    2000-12-01

    It is generally accepted that if surgery for Hirschsprung's disease is to be successful, ganglionic bowel must be anastomosed to the lower rectum or anal canal. Above the aganglionic distal bowel lies a transition zone (TZ) where more subtle abnormalities of innervation are apparent. The significance of this transition zone in respect to the functional outcome of surgery has received little attention. The aim of this study was to identify the incidence of transition zone pull-through (TZPT) in a cohort of children who underwent surgery for Hirschsprung's disease, to identify the reasons why TZPTs occurred, and to identify the functional consequences. The authors report the long-term outcome of these children with emphasis on bowel function and the results of subsequent surgery. A Retrospective study was conducted of children treated at a single institution from 1979 through 1994. TZPT patients were subject to detailed review of surgical records and histopathologic material. Thirteen children were identified with a TZPT. In 12 cases, histopathologic errors contributed to the TZPT: in 5 cases this was caused by single point biopsies missing an asymmetrical TZ, whereas in 7 cases the histopathologic features of the TZ were not recognized. In 1 case the TZPT was caused by surgical error. As a consequence of the TZPT 7 children underwent repeat pull-through. One child is fully continent, one has daytime fecal continence, and 2 others are incontinent. Two children have permanent stomas. One child is clean with antegrade colonic washouts. Repeat pull-throughs were not attempted in 6 children. Two children have achieved full continence, 2 have permanent stomas, 1 is clean with antegrade colonic washouts, and 1 child receives regular suppositories. Transition zone pull-throughs occurred because of a combination of surgical and histopathologic errors. The transition zone may follow an asymmetric course around the circumference of the bowel and may be missed if single

  16. Coexistence and transition between shear zones in slow granular flows.

    Science.gov (United States)

    Moosavi, Robabeh; Shaebani, M Reza; Maleki, Maniya; Török, János; Wolf, Dietrich E; Losert, Wolfgang

    2013-10-04

    We report experiments on slow granular flows in a split-bottom Couette cell that show novel strain localization features. Nontrivial flow profiles have been observed which are shown to be the consequence of simultaneous formation of shear zones in the bulk and at the boundaries. The fluctuating band model based on a minimization principle can be fitted to the experiments over a large variation of morphology and filling height with one single fit parameter, the relative friction coefficient μ(rel) between wall and bulk. The possibility of multiple shear zone formation is controlled by μ(rel). Moreover, we observe that the symmetry of an initial state, with coexisting shear zones at both side walls, breaks spontaneously below a threshold value of the shear velocity. A dynamical transition between two asymmetric flow states happens over a characteristic time scale which depends on the shear strength.

  17. "Textural analysis of multiparametric MRI detects transition zone prostate cancer".

    Science.gov (United States)

    Sidhu, Harbir S; Benigno, Salvatore; Ganeshan, Balaji; Dikaios, Nikos; Johnston, Edward W; Allen, Clare; Kirkham, Alex; Groves, Ashley M; Ahmed, Hashim U; Emberton, Mark; Taylor, Stuart A; Halligan, Steve; Punwani, Shonit

    2017-06-01

    To evaluate multiparametric-MRI (mpMRI) derived histogram textural-analysis parameters for detection of transition zone (TZ) prostatic tumour. Sixty-seven consecutive men with suspected prostate cancer underwent 1.5T mpMRI prior to template-mapping-biopsy (TPM). Twenty-six men had 'significant' TZ tumour. Two radiologists in consensus matched TPM to the single axial slice best depicting tumour, or largest TZ diameter for those with benign histology, to define single-slice whole TZ-regions-of-interest (ROIs). Textural-parameter differences between single-slice whole TZ-ROI containing significant tumour versus benign/insignificant tumour were analysed using Mann Whitney U test. Diagnostic accuracy was assessed by receiver operating characteristic area under curve (ROC-AUC) analysis cross-validated with leave-one-out (LOO) analysis. ADC kurtosis was significantly lower (p Textural features of the whole prostate TZ can discriminate significant prostatic cancer through reduced kurtosis of the ADC-histogram where significant tumour is included in TZ-ROI and reduced T1 entropy independent of tumour inclusion. • MR textural features of prostate transition zone may discriminate significant prostatic cancer. • Transition zone (TZ) containing significant tumour demonstrates a less peaked ADC histogram. • TZ containing significant tumour reveals higher post-contrast T1-weighted homogeneity. • The utility of MR texture analysis in prostate cancer merits further investigation.

  18. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    Directory of Open Access Journals (Sweden)

    Rackel eSan Nicolas

    2015-12-01

    Full Text Available The interfacial transition zone (ITZ is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE generated in an environmental scanning electron microscope (ESEM are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  19. 33 CFR 165.103 - Safety and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone...

    Science.gov (United States)

    2010-07-01

    ... within a 500-yard radius of any Liquefied Petroleum Gas (LPG) vessel while it is moored at the LPG... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones; LPG... and Security Zones; LPG Vessel Transits in Portland, Maine, Captain of the Port Zone, Portsmouth...

  20. POROUS MICROSTRUCTURE OF THE INTERFACIAL TRANSITION ZONE IN GEOPOLYMER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Steinerová M.

    2013-12-01

    Full Text Available The study deals with a comparison of the differences in the structure, composition and micromechanical properties of a metakaolinite geopolymer composite matrix, inside and outside of the interfacial transition zone (ITZ with quartz grains of added silica sand. The microstructure is investigated by a measurement of the mercury porosimetry, microscopy and by a measurement in SEM and AFM, completed by Raman spectroscopy. Weaker mechanical properties, micropores in the ITZ, a higher concentration of Al atoms and hydroxyl groups than in the ambient matrix were detected. The water transport is probably the reason for the micropore formation, caused by disequilibrium in the course of solid-phase building from geopolymer dispersion.

  1. The Root Transition Zone: A Hot Spot for Signal Crosstalk.

    Science.gov (United States)

    Kong, Xiangpei; Liu, Guangchao; Liu, Jiajia; Ding, Zhaojun

    2018-05-01

    The root transition zone (TZ), located between the apical meristem and basal elongation region, has a unique role in root growth and development. The root TZ is not only the active site for hormone crosstalk, but also the perception site for various environmental cues, such as aluminum (Al) stress and low phosphate (Pi) stress. We propose that the root TZ is a hot spot for the integration of diverse inputs from endogenous (hormonal) and exogenous (sensorial) stimuli to control root growth. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Response of mantle transition zone thickness to plume buoyancy flux

    Science.gov (United States)

    Das Sharma, S.; Ramesh, D. S.; Li, X.; Yuan, X.; Sreenivas, B.; Kind, R.

    2010-01-01

    The debate concerning thermal plumes in the Earth's mantle, their geophysical detection and depth characterization remains contentious. Available geophysical, petrological and geochemical evidence is at variance regarding the very existence of mantle plumes. Utilizing P-to-S converted seismic waves (P receiver functions) from the 410 and 660 km discontinuities, we investigate disposition of these boundaries beneath a number of prominent hotspot regions. The thickness of the mantle transition zone (MTZ), measured as P660s-P410s differential times (tMTZ), is determined. Our analyses suggest that the MTZ thickness beneath some hotspots correlates with the plume strength. The relationship between tMTZ, in response to the thermal perturbation, and the strength of plumes, as buoyancy flux B, follows a power law. This B-tMTZ behavior provides unprecedented insights into the relation of buoyancy flux and excess temperature at 410-660 km depth below hotspots. We find that the strongest hotspots, which are located in the Pacific, are indeed plumes originating at the MTZ or deeper. According to the detected power law, even the strongest plumes may not shrink the transition zone by significantly more than ~40 km (corresponding to a maximum of 300-400° excess temperature).

  3. Measurements of traveling transition zone along a superconductor

    International Nuclear Information System (INIS)

    Lottin, J.C.; Miller, J.R.; Lue, J.W.; Dresner, L.

    1978-01-01

    The spatial variation of the temperature in a traveling superconducting-normal transition zone can provide valuable information on transient heat transfer in realistic coil conditions. In this paper, temperature wave curves are presented for several transport currents corresponding to propagation and recovery in a high magnetic field. The temperature profiles have been constructed in the form T = T (x + vt) by measuring the wave velocity and the temperature at one point as a function of time. The temperature is measured directly with differential thermocouples; simultaneous voltage measurements provide a continuous temperature reference in the current sharing region. Information is given about thermocouple calibration in the high magnetic field and about the temperature and magnetic field dependence of the thermal conductivity of the sample

  4. Analytical Determination of the Boundaries of Transition Natural Zones (Ecotones

    Directory of Open Access Journals (Sweden)

    Rulev Aleksandr Sergeevich

    2015-04-01

    Full Text Available The morphological units that are part of the catena, are recognized in accordance with the response to the geomorphological and soil processes. The spatial relationship is the main unit between them. In this regard, the landscape patterns acquire a cascade type, and their main link becomes the zonal catena, which has specific stable features, reflecting the dependence of the complex of natural conditions and processes of latitude. However, clear-cut boundaries do not exist – they have spatial and temporal displacement, associated with the cyclical nature of the global climatic processes. The landscapes in these transition zones (ecotones a priori can be considered unstable. The detection of ecotones boundaries provides the opportunity to divide natural zones to potentially stable and potentially unstable parts for planning measures on preventing the degradation of landscapes localized in them. The latitude of the ecotones localization can be determined through the connection of the radiation heat flux on land (R with the normalized geographical latitude of the subboreal belt (x, which is described by the equation of the energy balance, expressed in the logistic function R = А / [1 + 0,72 exp(4,25 – Bx] + C.

  5. Receiver Function Imaging of Mantle Transition Zone Discontinuities Beneath Alaska

    Science.gov (United States)

    Dahm, Haider Hassan Faraj

    Subduction of tectonic plates is one of the most important tectonic processes, yet many aspects of subduction zone geodynamics remain unsolved and poorly understood, such as the depth extent of the subducted slab and its geometry. The Alaska subduction zone, which is associated with the subduction of the Pacific Plate beneath the North America plate, has a complex tectonic setting and carries a series of subduction episodes, and represents an excellent target to study such plate tectonic processes. Previous seismological studies in Alaska have proposed different depth estimations and geometry for the subducted slab. The Mantle transition zone discontinuities of the 410km and the 660 km provide independent constraints on the depth extent of the subducted slabs. We conducted a receiver function study to map the topography of the 410 km and the 660 km discontinuities beneath Alaska and its adjacent areas by taking advantage of the teleseismic data from the new USArray deployment in Alaska and northwestern Canada. Stacking over 75,000 high-quality radial receiver functions recorded in Alaska with more than 40 years of recording period, the topographies of the 410 km and 660 km are mapped. The depths of both d410 and d660 show systematic spatial variations, the mean depth of d410 and d660 are within 6 km and 6 km from the global average, respectively. The mean MTZ thickness of the entire study area is within -2 km from the global average of 250 km, suggesting normal MTZ conditions on average. Central and south-central Alaska are characterized by a larger than normal MTZ thickness, suggesting that the subducting Pacific slab is thermally interacted with the MTZ. This study shows that lateral upper mantle velocity variations contribute the bulk of the observed apparent undulations of the MTZ discontinuities.

  6. STEM tomography analysis of the trypanosome transition zone.

    Science.gov (United States)

    Trépout, Sylvain; Tassin, Anne-Marie; Marco, Sergio; Bastin, Philippe

    2018-04-01

    The protist Trypanosoma brucei is an emerging model for the study of cilia and flagella. Here, we used scanning transmission electron microscopy (STEM) tomography to describe the structure of the trypanosome transition zone (TZ). At the base of the TZ, nine transition fibres irradiate from the B microtubule of each doublet towards the membrane. The TZ adopts a 9 + 0 structure throughout its length of ∼300 nm and its lumen contains an electron-dense structure. The proximal portion of the TZ has an invariant length of 150 nm and is characterised by a collarette surrounding the membrane and the presence of electron-dense material between the membrane and the doublets. The distal portion exhibits more length variation (from 55 to 235 nm) and contains typical Y-links. STEM analysis revealed a more complex organisation of the Y-links compared to what was reported by conventional transmission electron microscopy. Observation of the very early phase of flagellum assembly demonstrated that the proximal portion and the collarette are assembled early during construction. The presence of the flagella connector that maintains the tip of the new flagellum to the side of the old was confirmed and additional filamentous structures making contact with the membrane of the flagellar pocket were also detected. The structure and potential functions of the TZ in trypanosomes are discussed, as well as its mode of assembly. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Transition zone cells reach G2 phase before initiating elongation in maize root apex

    Directory of Open Access Journals (Sweden)

    M. Victoria Alarcón

    2017-06-01

    Full Text Available Root elongation requires cell divisions in the meristematic zone and cell elongation in the elongation zone. The boundary between dividing and elongating cells is called the transition zone. In the meristem zone, initial cells are continuously dividing, but on the basal side of the meristem cells exit the meristem through the transition zone and enter in the elongation zone, where they stop division and rapidly elongate. Throughout this journey cells are accompanied by changes in cell cycle progression. Flow cytometry analysis showed that meristematic cells are in cycle, but exit when they enter the elongation zone. In addition, the percentage of cells in G2 phase (4C strongly increased from the meristem to the elongation zone. However, we did not observe remarkable changes in the percentage of cells in cell cycle phases along the entire elongation zone. These results suggest that meristematic cells in maize root apex stop the cell cycle in G2 phase after leaving the meristem.

  8. The upper-mantle transition zone beneath the Chile-Argentina flat subduction zone

    Science.gov (United States)

    Bagdo, Paula; Bonatto, Luciana; Badi, Gabriela; Piromallo, Claudia

    2016-04-01

    The main objective of the present work is the study of the upper mantle structure of the western margin of South America (between 26°S and 36°S) within an area known as the Chile-Argentina flat subduction zone. For this purpose, we use teleseismic records from temporary broad band seismic stations that resulted from different seismic experiments carried out in South America. This area is characterized by on-going orogenic processes and complex subduction history that have profoundly affected the underlying mantle structure. The detection and characterization of the upper mantle seismic discontinuities are useful to understand subduction processes and the dynamics of mantle convection; this is due to the fact that they mark changes in mantle composition or phase changes in mantle minerals that respond differently to the disturbances caused by mantle convection. The discontinuities at a depth of 410 km and 660 km, generally associated to phase changes in olivine, vary in width and depth as a result of compositional and temperature anomalies. As a consequence, these discontinuities are an essential tool to study the thermal and compositional structure of the mantle. Here, we analyze the upper-mantle transition zone discontinuities at a depth of 410 km and 660 km as seen from Pds seismic phases beneath the Argentina-Chile flat subduction.

  9. Importance of ecotone type to landscape dynamics at biome transition zones

    Science.gov (United States)

    Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsc...

  10. Analysis of Bridge Transition Zones in Railways Considering the Moisture Condition of the Ballast and Subballast

    NARCIS (Netherlands)

    Wang, Haoyu; Silvast, Mika; Markine, V.L.; Wiljanen, Bruce

    2017-01-01

    Transition zones in railway tracks are the locations with considerable changes in vertical support structures, e.g., near bridges. Due to possible water flow constrictions in transition zone structures, there is frequently an increased moisture level in the ballast/subballast layers, which is a

  11. Impact of spectral transition zone in reference ENIGMA configuration

    International Nuclear Information System (INIS)

    Aliberti, G.; Palmiotti, G.; Taiwo, T. A.; Tommasi, J.

    2005-01-01

    Investigation of Gas-cooled reactor at Masurca) is being planned for Cadarache. This new experiment would provide better understanding of GFR neutronic features and will be the basis for the extension of current neutronics code validation domain (particularly, the ERANOS code system in France) to the analysis of GFRs. Experimental planning and decisions are ongoing for ENIGMA. One of the items that have been evaluated is the feasibility of obtaining different flux spectra in the ENIGMA reference configuration, giving the flexibility of simulating a large series of proposed gas-cooled fast systems with harder or softer spectra. In order to achieve this goal it was proposed to use a spectral transition zone in the center region of the ENIGMA core configuration. Another goal of the study is to evaluate the impact of the graphite cross-sections on the performance characteristics of the MASURCA configurations. The work was supported by ANL, through the residence of one of the authors at CEA-Cadarache in 2005. In this report, the impacts of the transition zone on the core physics parameters of the reference ENIGMA configuration are summarized

  12. Microbial Mineral Colonization Across a Subsurface Redox Transition Zone

    Directory of Open Access Journals (Sweden)

    Brandon eConverse

    2015-08-01

    Full Text Available This study employed 16S rRNA gene amplicon pyrosequencing to examine the hypothesis that chemolithotrophic Fe(II-oxidizing bacteria (FeOB would preferentially colonize the Fe(II-bearing mineral biotite compared to quartz sand when the minerals were incubated in situ within a subsurface redox transition zone (RTZ at the Hanford 300 Area site in Richland, WA, USA. The work was motivated by the recently documented presence of neutral-pH chemolithotrophic FeOB capable of oxidizing structural Fe(II in primary silicate and secondary phyllosilicate minerals in 300 Area sediments and groundwater (Benzine et al., 2013. Sterilized portions of sand+biotite or sand alone were incubated in situ for five months within a multilevel sampling (MLS apparatus that spanned a ca. 2-m interval across the RTZ in two separate groundwater wells. Parallel MLS measurements of aqueous geochemical species were performed prior to deployment of the minerals. Contrary to expectations, the 16S rRNA gene libraries showed no significant difference in microbial communities that colonized the sand+biotite versus sand-only deployments. Both mineral-associated and groundwater communities were dominated by heterotrophic taxa, with organisms from the Pseudomonaceae accounting for up to 70% of all reads from the colonized minerals. These results are consistent with previous results indicating the capacity for heterotrophic metabolism (including anaerobic metabolism below the RTZ as well as the predominance of heterotrophic taxa within 300 Area sediments and groundwater. Although heterotrophic organisms clearly dominated the colonized minerals, several putative lithotrophic (NH4+, H2, Fe(II, and HS- oxidizing taxa were detected in significant abundance above and within the RTZ. Such organisms may play a role in the coupling of anaerobic microbial metabolism to oxidative pathways with attendant impacts on elemental cycling and redox-sensitive contaminant behavior in the vicinity of the

  13. Structural Health Monitoring of Railway Transition Zones Using Satellite Radar Data.

    Science.gov (United States)

    Wang, Haoyu; Chang, Ling; Markine, Valeri

    2018-01-31

    Transition zones in railway tracks are locations with considerable changes in the rail-supporting structure. Typically, they are located near engineering structures, such as bridges, culverts and tunnels. In such locations, severe differential settlements often occur due to the different material properties and structure behavior. Without timely maintenance, the differential settlement may lead to the damage of track components and loss of passenger's comfort. To ensure the safety of railway operations and reduce the maintenance costs, it is necessary to consecutively monitor the structural health condition of the transition zones in an economical manner and detect the changes at an early stage. However, using the current in situ monitoring of transition zones is hard to achieve this goal, because most in situ techniques (e.g., track-measuring coaches) are labor-consuming and usually not frequently performed (approximately twice a year in the Netherlands). To tackle the limitations of the in situ techniques, a Satellite Synthetic Aperture Radar (InSAR) system is presented in this paper, which provides a potential solution for a consecutive structural health monitoring of transition zones with bi-/tri-weekly data update and mm-level precision. To demonstrate the feasibility of the InSAR system for monitoring transition zones, a transition zone is tested. The results show that the differential settlement in the transition zone and the settlement rate can be observed and detected by the InSAR measurements. Moreover, the InSAR results are cross-validated against measurements obtained using a measuring coach and a Digital Image Correlation (DIC) device. The results of the three measuring techniques show a good correlation, which proves the applicability of InSAR for the structural health monitoring of transition zones in railway track.

  14. Structural Health Monitoring of Railway Transition Zones Using Satellite Radar Data

    Directory of Open Access Journals (Sweden)

    Haoyu Wang

    2018-01-01

    Full Text Available Transition zones in railway tracks are locations with considerable changes in the rail-supporting structure. Typically, they are located near engineering structures, such as bridges, culverts and tunnels. In such locations, severe differential settlements often occur due to the different material properties and structure behavior. Without timely maintenance, the differential settlement may lead to the damage of track components and loss of passenger’s comfort. To ensure the safety of railway operations and reduce the maintenance costs, it is necessary to consecutively monitor the structural health condition of the transition zones in an economical manner and detect the changes at an early stage. However, using the current in situ monitoring of transition zones is hard to achieve this goal, because most in situ techniques (e.g., track-measuring coaches are labor-consuming and usually not frequently performed (approximately twice a year in the Netherlands. To tackle the limitations of the in situ techniques, a Satellite Synthetic Aperture Radar (InSAR system is presented in this paper, which provides a potential solution for a consecutive structural health monitoring of transition zones with bi-/tri-weekly data update and mm-level precision. To demonstrate the feasibility of the InSAR system for monitoring transition zones, a transition zone is tested. The results show that the differential settlement in the transition zone and the settlement rate can be observed and detected by the InSAR measurements. Moreover, the InSAR results are cross-validated against measurements obtained using a measuring coach and a Digital Image Correlation (DIC device. The results of the three measuring techniques show a good correlation, which proves the applicability of InSAR for the structural health monitoring of transition zones in railway track.

  15. Articular Cartilage Increases Transition Zone Regeneration in Bone-tendon Junction Healing

    Science.gov (United States)

    Qin, Ling; Lee, Kwong Man; Leung, Kwok Sui

    2008-01-01

    The fibrocartilage transition zone in the direct bone-tendon junction reduces stress concentration and protects the junction from failure. Unfortunately, bone-tendon junctions often heal without fibrocartilage transition zone regeneration. We hypothesized articular cartilage grafts could increase fibrocartilage transition zone regeneration. Using a goat partial patellectomy repair model, autologous articular cartilage was harvested from the excised distal third patella and interposed between the residual proximal two-thirds bone fragment and tendon during repair in 36 knees. We evaluated fibrocartilage transition zone regeneration, bone formation, and mechanical strength after repair at 6, 12, and 24 weeks and compared them with direct repair. Autologous articular cartilage interposition resulted in more fibrocartilage transition zone regeneration (69.10% ± 14.11% [mean ± standard deviation] versus 8.67% ± 7.01% at 24 weeks) than direct repair at all times. There was no difference in the amount of bone formation and mechanical strength achieved. Autologous articular cartilage interposition increases fibrocartilage transition zone regeneration in bone-tendon junction healing, but additional research is required to ascertain the mechanism of stimulation and to establish the clinical applicability. PMID:18987921

  16. Fatigue Resistance of the Grain Size Transition Zone in a Dual Microstructure Superalloy Disk

    Science.gov (United States)

    Gabb, T. P.; Kantzos, P. T.; Telesman, J.; Gayda, J.; Sudbrack, C. K.; Palsa, B. S.

    2010-01-01

    Mechanical property requirements vary with location in nickel-based superalloy disks. To maximize the associated mechanical properties, heat treatment methods have been developed for producing tailored microstructures. In this study, a specialized heat treatment method was applied to produce varying grain microstructures from the bore to the rim portions of a powder metallurgy processed nickel-based superalloy disk. The bore of the contoured disk consisted of fine grains to maximize strength and fatigue resistance at lower temperatures. The rim microstructure of the disk consisted of coarse grains for maximum resistance to creep and dwell crack growth at high temperatures up to 704 C. However, the fatigue resistance of the grain size transition zone was unclear, and needed to be evaluated. This zone was located as a band in the disk web between the bore and rim. Specimens were extracted parallel and transverse to the transition zone, and multiple fatigue tests were performed at 427 and 704 C. Mean fatigue lives were lower at 427 C than for 704 C. Specimen failures often initiated at relatively large grains, which failed on crystallographic facets. Grain size distributions were characterized in the specimens, and related to the grains initiating failures as well as location within the transition zone. Fatigue life decreased with increasing maximum grain size. Correspondingly, mean fatigue resistance of the transition zone was slightly higher than that of the rim, but lower than that of the bore. The scatter in limited tests of replicates was comparable for all transition zone locations examined.

  17. Buckling instabilities of subducted lithosphere beneath the transition zone

    NARCIS (Netherlands)

    Ribe, N.M.; Stutzmann, E.; Ren, Y.; Hilst, R.D. van der

    2007-01-01

    A sheet of viscous fluid poured onto a surface buckles periodically to generate a pile of regular folds. Recent tomographic images beneath subduction zones, together with quantitative fluid mechanical scaling laws, suggest that a similar instability can occur when slabs of subducted oceanic

  18. Risk Assessment of Maize Drought Disaster in Agro-Pastoral Transitional Zone in North China

    Science.gov (United States)

    Jia, H.; Pan, D.

    2017-12-01

    Agricultural drought is one of the focuses of global concern and one of the natural disasters that affect the agriculture production mostly in China. Farming-pastoral zones in China are located in the monsoon fringe area, precipitation of which is extremely unstable, and drought occurs frequently. The agro-pastoral transitional zone in North China is one of the main producing areas of northern spring maize in northern China, and maize is the second largest grain crop in the region. An assessment of the risk of drought disaster in this region is therefore important in ensuring a reduction in such disasters and an increase in food security. A risk assessment model, EPIC (Environmental Policy Integrated Climate) model, for maize drought disasters based on the Erosion Productivity Impact Calculator crop model is proposed for areas with the topographic characteristics of agro-pastoral transitional zone in North China. The results showed that the hazard risk level for the maize zone of agro-pastoral transitional zone in North China is generally high. Most hazard index values were between 0.4 and 0.5, accounting for 48.77% of total study area. The high-risk areas were mainly distributed in Ordos Plateau (South of Inner Mongolia Autonomous region), South of Ningxia Hui Autonomous Region and Center of Gansu Province. These results provide a scientific basis and support for the reduction of agricultural drought disasters and an increase in food security in the agro-pastoral transitional zone in North China.

  19. Mapping the mantle transition zone beneath the central Mid-Atlantic Ridge using Ps receiver functions.

    Science.gov (United States)

    Agius, M. R.; Rychert, C.; Harmon, N.; Kendall, J. M.

    2017-12-01

    Determining the mechanisms taking place beneath ridges is important in order to understand how tectonic plates form and interact. Of particular interest is establishing the depth at which these processes originate. Anomalies such as higher temperature within the mantle transition zone may be inferred seismically if present. However, most ridges are found in remote locations beneath the oceans restricting seismologists to use far away land-based seismometers, which in turn limits the imaging resolution. In 2016, 39 broadband ocean-bottom seismometers were deployed across the Mid-Atlantic Ridge, along the Romanche and Chain fracture zones as part of the PI-LAB research project (Passive Imaging of the Lithosphere and Asthenosphere Boundary). The one-year long seismic data is now retrieved and analysed to image the mantle transition zone beneath the ridge. We determine P-to-s (Ps) receiver functions to illuminate the 410- and 660-km depth mantle discontinuities using the extended multitaper deconvolution. The data from ocean-bottom seismometers have tilt and compliance noise corrections and is filtered between 0.05-0.2 Hz to enhance the signal. 51 teleseismic earthquakes generated hundreds of good quality waveforms, which are then migrated to depth in 3-D. The topography at the d410 deepens towards the west of the Romanche and Chain fracture zone by 15 km, whereas the topography of d660 shallows beneath the ridge between the two zones. Transition zone thickness thins from 5 to 20 km. Thermal anomalies determined from temperature relationships with transition zone thickness and depth variations of the d410 and d660 suggests hotter temperatures of about 200 K. Overall, the result suggests mid-ocean ridges may have associated thermal signatures as deep as the transition zone.

  20. Fatigue Failure Modes of the Grain Size Transition Zone in a Dual Microstructure Disk

    Science.gov (United States)

    Gabb, Timothy P.; Kantzos, Pete T.; Palsa, Bonnie; Telesman, Jack; Gayda, John; Sudbrack, Chantal K.

    2012-01-01

    Mechanical property requirements vary with location in nickel-based superalloy disks. In order to maximize the associated mechanical properties, heat treatment methods have been developed for producing tailored grain microstructures. In this study, fatigue failure modes of a grain size transition zone in a dual microstructure disk were evaluated. A specialized heat treatment method was applied to produce varying grain microstructure in the bore to rim portions of a powder metallurgy processed nickel-based superalloy disk. The transition in grain size was concentrated in a zone of the disk web, between the bore and rim. Specimens were extracted parallel and transversely across this transition zone, and multiple fatigue tests were performed at 427 C and 704 C. Grain size distributions were characterized in the specimens, and related to operative failure initiation modes. Mean fatigue life decreased with increasing maximum grain size, going out through the transition zone. The scatter in limited tests of replicates was comparable for failures of uniform gage specimens in all transition zone locations examined.

  1. Heterogeneous distribution of water in the mantle transition zone beneath United States inferred from seismic observations

    Science.gov (United States)

    Wang, Y.; Pavlis, G. L.; Li, M.

    2017-12-01

    The amount of water in the Earth's deep mantle is critical for the evolution of the solid Earth and the atmosphere. Mineral physics studies have revealed that Wadsleyite and Ringwoodite in the mantle transition zone could store several times the volume of water in the ocean. However, the water content and its distribution in the transition zone remain enigmatic due to lack of direct observations. Here we use seismic data from the full deployment of the Earthscope Transportable Array to produce 3D image of P to S scattering of the mantle transition zone beneath the United States. We compute the image volume from 141,080 pairs of high quality receiver functions defined by the Earthscope Automated Receiver Survey, reprocessed by the generalized iterative deconvolution method and imaged by the plane wave migration method. We find that the transition zone is filled with previously unrecognized small-scale heterogeneities that produce pervasive, negative polarity P to S conversions. Seismic synthetic modeling using a point source simulation method suggests two possible structures for these objects: 1) a set of randomly distributed blobs of slight difference in size, and 2) near vertical diapir structures from small scale convections. Combining with geodynamic simulations, we interpret the observation as compositional heterogeneity from small-scale, low-velocity bodies that are water enriched. Our results indicate there is a heterogeneous distribution of water through the entire mantle transition zone beneath the contiguous United States.

  2. Transit and radial velocity survey efficiency comparison for a habitable zone Earth

    International Nuclear Information System (INIS)

    Burke, Christopher J.; McCullough, P. R.

    2014-01-01

    Transit and radial velocity searches are two techniques for identifying nearby extrasolar planets to Earth that transit bright stars. Identifying a robust sample of these exoplanets around bright stars for detailed atmospheric characterization is a major observational undertaking. In this study we describe a framework that answers the question of whether a transit or radial velocity survey is more efficient at finding transiting exoplanets given the same amount of observing time. Within the framework we show that a transit survey's window function can be approximated using the hypergeometric probability distribution. We estimate the observing time required for a transit survey to find a transiting Earth-sized exoplanet in the habitable zone (HZ) with an emphasis on late-type stars. We also estimate the radial velocity precision necessary to detect the equivalent HZ Earth-mass exoplanet that also transits when using an equal amount of observing time as the transit survey. We find that a radial velocity survey with σ rv ∼ 0.6 m s –1 precision has comparable efficiency in terms of observing time to a transit survey with the requisite photometric precision σ phot ∼ 300 ppm to find a transiting Earth-sized exoplanet in the HZ of late M dwarfs. For super-Earths, a σ rv ∼ 2.0 m s –1 precision radial velocity survey has comparable efficiency to a transit survey with σ phot ∼ 2300 ppm.

  3. Perception of the Transition Zones from Urban to Suburban Area Using Mobile Eye

    Directory of Open Access Journals (Sweden)

    Paolo Magris

    2014-12-01

    Full Text Available Road users adjust their driving behavior based on the perception of the route and the surrounding environment. The eye-tracking technology allows interpreting the driver behavior, analyzing aspects otherwise not considered in the design stage. This technology has been used for transition zone analysis at town entrances along the SP 610 “Selice Montanara”, to verify the efficiency of gateway created to reduce the input speed in urban areas. Results show that the installation of traffic calming measures at transition zones leads to a change of the environment perception by drivers, and consequently safety increase.

  4. Childhood obesity in transition zones: an analysis using structuration theory.

    Science.gov (United States)

    Chan, Christine; Deave, Toity; Greenhalgh, Trisha

    2010-07-01

    Childhood obesity is particularly prevalent in areas that have seen rapid economic growth, urbanisation, cultural transition, and commodification of food systems. Structuration theory may illuminate the interaction between population and individual-level causes of obesity. We conducted in-depth ethnographies of six overweight/obese and four non-overweight preschool children in Hong Kong, each followed for 12-18 months. Analysis was informed by Stones' strong structuration theory. Risk factors played out differently for different children as social structures were enacted at the level of family and preschool. The network of caregiving roles and relationships around the overweight/obese child was typically weak and disjointed, and the primary caregiver appeared confused by mixed messages about what is normal, expected and legitimate behaviour. In particular, external social structures created pressure to shift childcare routines from the logic of nurturing to the logic of consumption. Our findings suggest that threats to what Giddens called ontological security in the primary caregiver may underpin the poor parenting, family stress and weak mealtime routines that mediate the relationship between an obesogenic environment and the development of obesity in a particular child. This preliminary study offers a potentially transferable approach for studying emerging epidemics of diseases of modernity in transition societies.

  5. Analysis of the Dynamic Wheel Loads in Railway Transition Zones Considering the Moisture Condition of the Ballast and Subballast

    Directory of Open Access Journals (Sweden)

    Haoyu Wang

    2017-11-01

    Full Text Available Transition zones in railway tracks are the locations with considerable changes in vertical support structures, e.g., near bridges. Due to possible water flow constrictions in transition zone structures, there is frequently an increased moisture level in the ballast/subballast layers, which is a potential source of track degradation. This paper presents results of the moisture condition measured in three transition zones using ground penetrating radar, where the ballast/subballast are analyzed. The relationship between the moisture condition and track degradation in the transition zones is studied by comparing it to the longitudinal track level that is measured by the track inspection coaches. A strong connection is found between the high moisture condition and track degradation in the transition zones. The dynamic behavior of the transition zones with high moisture condition is analyzed using the Finite Element method. Differential stiffness and settlement are taken into consideration in the transition zone model, which is also coupled with a vehicle. The ballast/subballast layers are modelled as solid elements. Increased moisture conditions are considered as a reduction of elastic modulus, according to laboratory findings. Results show that high moisture leads to an increase of dynamic wheel loads in the transition zone, which explains the connection and confirms that the high moisture condition is a source of transition zone problems.

  6. The influence of train running direction and track supports position on the behaviour of transition zones

    Energy Technology Data Exchange (ETDEWEB)

    Sañudo Ortega, R.; Miranda Manzanares, M.; Markine, V.; Dell' Olio, L.

    2016-07-01

    Different types of track infrastructure can be found along railway lines. Separation zones between these different types of structures are the source of a lot of problems. Transition zones on a railway line represent a gradual solution for the problems between conventional railway structure and singular structures located at different points along the line. The different nature, positioning and geometry used with the materials generate changes in the stiffness on both sides of these singular zones leading to an increase in wear and a loss of geometry, with the associated maintenance costs. This article describes the use of mathematical modelling to represent the behaviour of these zones as a function of train running direction and track supports. Available research into transition zones has not studied these separation points where high increases in load are generated for very short periods of time. Finite elements are used to model two types of track (conventional ballasted track and slab track), using a vehicle to dynamically simulate the behaviour in these zones as a function of train running direction and the position of track supports. The magnitudes analysed were the vertical stresses and the vertical displacements under the sleepers and the supports in both types of structure. The results show increased stresses at the separation zone between both structures which varied in magnitude and position depending most of track supports’ location than the train running direction. (Author)

  7. Global Transition Zone Anisotropy and Consequences for Mantle Flow and Earth's Deep Water Cycle

    Science.gov (United States)

    Beghein, C.; Yuan, K.

    2011-12-01

    The transition zone has long been at the center of the debate between multi- and single-layered convection models that directly relate to heat transport and chemical mixing throughout the mantle. It has also been suggested that the transition zone is a reservoir that collects water transported by subduction of the lithosphere into the mantle. Since water lowers mantle minerals density and viscosity, thereby modifying their rheology and melting behavior, it likely affects global mantle dynamics and the history of plate tectonics. Constraining mantle flow is therefore important for our understanding of Earth's thermochemical evolution and deep water cycle. Because it can result from deformation by dislocation creep during convection, seismic anisotropy can help us model mantle flow. It is relatively well constrained in the uppermost mantle, but its presence in the transition zone is still debated. Its detection below 250 km depth has been challenging to date because of the poor vertical resolution of commonly used datasets. In this study, we used global Love wave overtone phase velocity maps, which are sensitive to structure down to much larger depths than fundamental modes alone, and have greater depth resolution than shear wave-splitting data. This enabled us to obtain a first 3-D model of azimuthal anisotropy for the upper 800km of the mantle. We inverted the 2Ψ terms of anisotropic phase velocity maps [Visser, et al., 2008] for the first five Love wave overtones between 35s and 174s period. The resulting model shows that the average anisotropy amplitude for vertically polarized shear waves displays two main stable peaks: one in the uppermost mantle and, most remarkably, one in the lower transition zone. F-tests showed that the presence of 2Ψ anisotropy in the transition zone is required to improve the third, fourth, and fifth overtones fit. Because of parameter trade-offs, however, we cannot exclude that the anisotropy is located in the upper transition zone as

  8. Interaction of the Cyprus/Tethys Slab With the Mantle Transition Zone Beneath Anatolia

    Science.gov (United States)

    Thompson, D. A.; Rost, S.; Taylor, G.; Cornwell, D. G.

    2017-12-01

    The geodynamics of the eastern Mediterranean are dominated by northward motion of the Arabian/African continents and subduction of the oldest oceanic crust on the planet along the Aegean and Cyprean trenches. These slabs have previously been imaged using seismic tomography on a continental scale, but detailed information regarding their descent from upper to lower mantle and how they interact with the mantle transition zone have been severely lacking. The Dense Array for North Anatolia (DANA) was a 73 station passive seismic deployment active between 2012-2013 with the primary aim of imaging shallow structure beneath the North Anatolian Fault. However, we exploit the exceptional dataset recorded by DANA to characterise a region where the Cyprus Slab impinges upon the mantle transition zone beneath northern Turkey, providing arguably the most detailed view of a slab as it transits from the upper to lower mantle. We map varying depths and amplitudes of the transition zone seismic discontinuities (`410', `520' and `660') in 3D using over 1500 high quality receiver functions over an area of approximately 200km x 300km. The `410' is observed close to its predicted depth, but the `660' is depressed to >670 km across the entirety of the study region. This is consistent with an accumulation of cold subducted material at the base of the upper mantle, and the presence of a `520' discontinuity in the vicinity of the slab surface also suggests that the slab is present deep within the transition zone. Anomalous low velocity layers above and within the transition zone are constrained and may indicate hydration and ongoing mass/fluid flux between upper and lower mantle in the presence of subduction. The results of the study have implications not only for the regional geodynamics of Anatolia, but also for slab dynamics globally.

  9. Study on microstructure of transition zone and its strong contrast of single T700 carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xinshuang; Zhang, Kexiang [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Fan, Zhen; Feng, Zhihai [National Key Laboratory of Advanced Functional Composite Materials, Aerospace Research Institute of Materials and Processing Technology, Beijing 100076 (China); He, LianLong, E-mail: llhe@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2017-06-01

    Highlights: • The transition zone of T700 carbon fiber was first identified with higher density in addition to higher orientation. • The higher sample density still existed while the higher orientation disappeared after heat treatment at 2800 °C. • The strong contrast of the transition zone mainly results from its higher density. • The transition zone with higher density and orientation may exist not only in the T700 but other PAN-based carbon fibers. - Abstract: The transition zone (TZ) between the skin and core of Toray T700 carbon fiber was investigated by transmission electron microscopy. The higher basal-plane orientation was identified in the TZ compared with the skin and core, but it disappeared after heat treatment at 2800 °C. Plasmon peak energy in the TZ was higher than that in the skin and core about 0.7–0.8 eV, indicating the TZ with higher density. No element concentration existed in the TZ. The TZ with strong contrast manifests itself before and after heat treatment, and formation mechanism of its strong contrast was proposed.

  10. Cilium transition zone proteome reveals compartmentalization and differential dynamics of ciliopathy complexes

    Czech Academy of Sciences Publication Activity Database

    Dean, S.; Moreira-Leite, F.; Varga, Vladimír; Gull, K.

    2016-01-01

    Roč. 113, č. 35 (2016), E5135-E5143 ISSN 0027-8424 Institutional support: RVO:68378050 Keywords : transition zone * cilium/flagellum * BBSome * MKS/B9 complex * trypanosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.661, year: 2016

  11. Garnet Yield Strength at High Pressures and Implications for Upper Mantle and Transition Zone Rheology

    International Nuclear Information System (INIS)

    Kavner, A.

    2008-01-01

    Garnet helps control the mechanical behavior of the Earth's crust, mantle, and transition zone. Here, measurements are presented suggesting that garnet, long considered to be a high-viscosity phase, is actually weaker than the other dominant components in the transition zone. The mechanical behavior of garnet at high pressures was examined using radial diffraction techniques in the diamond anvil cell. The yield strength of grossular garnet was inferred from synchrotron X-ray measurements of differential lattice strains. The differential stress was found to increase from 1.3 (±0.6) GPa at a hydrostatic pressure 5.8 (±1.1) GPa to 4.1 (±0.4) GPa at 15.7 (±1.0) GPa, where it was level to 19 GPa. The strength results are consistent with inferred strength values for majorite garnet from measurements in the diamond cell normal geometry, bolstering the idea that garnet-structured materials may all have similar strengths. In this low-temperature, high differential stress regime, garnet is shown to be significantly weaker than anhydrous ringwoodite and to have a strength similar to hydrous ringwoodite. This result suggests that the presence of water in the transition zone may not be required to explain a weak rheology, and therefore models of transition zone behavior built assuming that garnet is the high-strength phase may need to be revised.

  12. Structural health monitoring of railway transition zones using satellite radar data

    NARCIS (Netherlands)

    Wang, Haoyu; Chang, L.; Markine, V.L.

    2018-01-01

    Transition zones in railway tracks are locationswith considerable changes in the rail-supporting structure. Typically, they are located near engineering structures, such as bridges, culverts and tunnels. In such locations, severe differential settlements often occur due to the different material

  13. Select transition zone prostate cancers may be radiocurable despite markedly elevated prostate-specific antigen levels

    International Nuclear Information System (INIS)

    D'Amico, Anthony V.; Kaplan, Irving

    1996-01-01

    In 1993, three men with transition zone prostate cancers were described (Stamey et al., J. Urol. 149: 510-515, 1993) who despite high prostate-specific antigen (PSA) levels remained PSA failure-free at 22 months postoperatively. This report illustrates that prolonged PSA failure free survival may be achieved when external beam radiation therapy is used to treat similar patients

  14. Household vulnerability and small ruminant benefits in transitional zone of Ghana

    NARCIS (Netherlands)

    Duku, S.; Zijpp, van der A.J.; Udo, H.M.J.

    2012-01-01

    This study investigated household vulnerability and small ruminant benefits in the transitional zone of Ghana. The dimensions of vulnerability considered were the sex and socio-economic status of the household head, and household morbidity and mortality. Data was collected from 11 key informants,

  15. Improvement of train-track interaction in transition zones via reduction of ballast damage

    NARCIS (Netherlands)

    Wang, H.; Markine, V.L.; Dollevoet, R.P.B.J.; Shevtsov, I.Y.

    2015-01-01

    Transition zones in railway tracks are locations with considerable changes in the vertical stiffness of the rail support. Typically they are located near engineering structures, such as bridges, culverts, tunnels and level crossings. In such locations, the differential settlement always exists and

  16. Long-rod penetration: the transition zone between rigid and hydrodynamic penetration modes

    Directory of Open Access Journals (Sweden)

    Jian-feng Lou

    2014-06-01

    Full Text Available Long-rod penetration in a wide range of velocity means that the initial impact velocity varies in a range from tens of meters per second to several kilometers per second. The long rods maintain rigid state when the impact velocity is low, the nose of rod deforms and even is blunted when the velocity gets higher, and the nose erodes and fails to lead to the consumption of long projectile when the velocity is very high due to instantaneous high pressure. That is, from low velocity to high velocity, the projectile undergoes rigid rods, deforming non-erosive rods, and erosive rods. Because of the complicated changes of the projectile, no well-established theoretical model and numerical simulation have been used to study the transition zone. Based on the analysis of penetration behavior in the transition zone, a phenomenological model to describe target resistance and a formula to calculate penetration depth in transition zone are proposed, and a method to obtain the boundary velocity of transition zone is determined. A combined theoretical analysis model for three response regions is built by analyzing the characteristics in these regions. The penetration depth predicted by this combined model is in good agreement with experimental result.

  17. 210Pb sediment dating in coastal transition zones: tropical saltmarshes.

    Science.gov (United States)

    Ruiz-Fernandez, A. C.; Sanchez-Cabeza, J. A.; Carnero-Bravo, V.; Perez-Bernal, L. H.

    2016-12-01

    Sea level rise (SLR) is one of the climate change effects expected to have the largest impact on coastal environments. SLR rates are not uniform around the planet and, therefore, local and regional data and trends are needed for proper adaptation plans. As long term monitoring stations of SLR are very scarce in most of the world, SLR trends obtained from 210Pb-dated sediment cores from tropical saltmarshes have become a practical alternative to obtain SLR trends within the past century, under the assumption that these ecosystems accrete at a similar rate to SLR. However, tropical saltmarshes are challenging environments for 210Pb dating: they are regularly dry, intermittently covered by seawater only during the highest tides, and sedimentary records often reflect the transition between terrestrial and marine environments (e.g. changes in grain size distribution, organic matter content and elemental composition) with all these factors contributing for atypical 210Pb depth profiles. In addition, 137Cs, the chronostratigraphic marker most commonly used to corroborate 210Pb dating, fails to be preserved in the sedimentary record in tropical areas, owing to its solubility in marine waters, if at all detectable. The present study describes the challenges and proposed solutions for 210Pb dating saltmarsh sediment cores from two saltmarsh areas (southern Gulf of California and Yucatan Peninsula) including the use of plutonium isotopes for corroboration purposes. Acknowledgements: projects CONACYT CB2010/153492 and PDCPN201301/214349; UNAM PAPIIT-IN203313 and the PRODEP network "Aquatic contamination: levels and effects" (year 3).

  18. Seismic Structure of Mantle Transition Zone beneath Northwest Pacific Subduction Zone and its Dynamic Implication

    Science.gov (United States)

    Li, J.; Guo, G.; WANG, X.; Chen, Q.

    2017-12-01

    The northwest Pacific subduction region is an ideal location to study the interaction between the subducting slab and upper mantle discontinuities. Various and complex geometry of the Pacific subducting slab can be well traced downward from the Kuril, Japan and Izu-Bonin trench using seismicity and tomography images (Fukao and Obayashi, 2013). Due to the sparse distribution of seismic stations in the sea, investigation of the deep mantle structure beneath the broad sea regions is very limited. In this study, we applied the well- developed multiple-ScS reverberations method (Wang et al., 2017) to analyze waveforms recorded by the Chinese Regional Seismic Network, the densely distributed temporary seismic array stations installed in east Asia. A map of the topography of the upper mantle discontinuities beneath the broad oceanic regions in northwest Pacific subduction zone is imaged. We also applied the receiver function analysis to waveforms recorded by stations in northeast China and obtain the detailed topography map beneath east Asia continental regions. We then combine the two kinds of topography of upper mantle discontinuities beneath oceanic and continental regions respectively, which are obtained from totally different methods. A careful image matching and spatial correlation is made in the overlapping study regions to calibrate results with different resolution. This is the first time to show systematically a complete view of the topography of the 410-km and 660-km discontinuities beneath the east Asia "Big mantle wedge" (Zhao and Ohtani, 2009) covering the broad oceanic and continental regions in the Northwestern Pacific Subduction zone. Topography pattern of the 660 and 410 is obtained and discussed. Especially we discovered a broad depression of the 410-km discontinuity covering more than 1000 km in lateral, which seems abnormal in the cold subducting tectonic environment. Based on plate tectonic reconstruction studies and HTHP mineral experiments, we

  19. Diffusion-weighted magnetic resonance imaging in the prostate transition zone: histopathological validation using magnetic resonance-guided biopsy specimens

    NARCIS (Netherlands)

    Hoeks, C.M.A.; Vos, E.K.; Bomers, J.G.R.; Barentsz, J.O.; Kaa, C.A. van de; Scheenen, T.W.J.

    2013-01-01

    OBJECTIVES: The objective of this study was to evaluate the apparent diffusion coefficient (ADC) of diffusion-weighted magnetic resonance (MR) imaging for the differentiation of transition zone cancer from non-cancerous transition zone with and without prostatitis and for the differentiation of

  20. Seismic investigation of an ocean-continent transition zone in the northern South China Sea

    Science.gov (United States)

    Zhu, J.; Qiu, X.; Xu, H.; Zhan, W.; Sun, Z.

    2011-12-01

    Rifted continental margins and basins are mainly formed by the lithospheric extension. Thined lithosphere of passive continental margins results in decompression melt of magma and created oceanic crust and thined ocean-continent transition (OCT) zone. Two refraction profiles used ocean bottom seismometers deployed in the broad continental shelf and three multi-channel seismic reflection lines in the northern South China Sea, acquired by the ship "Shiyan 2" of the South China Sea Institute of Oceanology, Chinese Academy of Sciences in 2010, are processed and interpreted in this study. Seismic reflection lines cut through the Dongsha rise, Zhu-1 and Zhu-2 depression within a Tertiary basin, Pear River Mouth basin (called as Zhujiangkou basin). These tectonic features are clear imaged in the seismic reflection records. Numerous normal faults, cutted through the basement and related to the stretch of the northern South China Sea margin, are imaged and interpreted. Reflection characteristics of the ocean-continent transition (OCT) zone are summaried and outlined. The COT zone is mainly divided into the northern syn-rift subsidence zone, central volcano or buried volcano uplift zone and tilt faulted block near the South Chia Sea basin. Compared to the previous seismic reflection data and refraction velocity models, the segmentation range of the OCT zone is outlined, from width of about 225 km in the northeastern South China Sea , of 160 km in the central to of 110 km in the north-central South China Sea. Based on the epicenter distribution of sporadic and large than 6 magnitude earthquakes, it suggests the OCT zone in the northern South China Sea at present is still an active seismic zone.

  1. Complex plume dynamics in the transition zone underneath the Hawaii hotspot: seismic imaging results

    Science.gov (United States)

    Cao, Q.; van der Hilst, R. D.; de Hoop, M. V.; Shim, S.

    2010-12-01

    In recent years, progress has been made in seismology to constrain the depth variations of the transition zone discontinuities, e.g. 410 km and 660 km discontinuities, which can be used to constrain the local temperature and chemistry profiles, and hence to infer the existences and morphology of mantle plumes. Taking advantage of the abundance of natural earthquake sources in western Pacific subduction zones and the many seismograph stations in the Americas, we used a generalized Radon transform (GRT), a high resolution inverse-scattering technique, of SS precursors to form 3-D images of the transition zone structures of a 30 degree by 40 degree area underneath Hawaii and the Hawaii-Emperor seamount chain. Rather than a simple mushroom-shape plume, our seismic images suggest complex plume dynamics interacting with the transition zone phase transitions, especially at the 660’ discontinuity. A conspicuous uplift of the 660 discontinuity in a region of 800km in diameter is observed to the west of Hawaii. No correspondent localized depression of the 410 discontinuity is found. This lack of correlation between and differences in lateral length scale of the topographies of the 410 and 660 km discontinuities are consistent with many geodynamical modeling results, in which a deep-mantle plume impinging on the transition zone, creating a pond of hot material underneath endothermic phase change at 660 km depth, and with secondary plumes connecting to the present-day hotspot at Earth’s surface. This more complex plume dynamics suggests that the complicated mass transport process across the transition zone should be taken into account when we try to link the geochemical observations of Hawaiian basalt geochemistry at the Earth’s surface to deep mantle domains. In addition to clear signals at 410km, 520km and 660km depth, the data also reveals rich structures near 350km depth and between 800 - 1000km depth, which may be regional, laterally intermittent scatter interfaces

  2. Dynamics of baroclinic wave pattern in transition zones between different flow regimes

    International Nuclear Information System (INIS)

    Larcher, Thomas von; Egbers, Christoph

    2005-01-01

    Baroclinic waves, both steady and time-dependent, are studied experimentally in a differentially heated rotating cylindrical gap with a free surface, cooled from within. Water is used as working fluid. We focus especially on transition zones between different flow regimes, where complex flow pattern like mixed-mode states are found. The transition from steady wave regime to irregular flow is also of particular interest. The surface flow is observed with visualisation techniques. Velocity time series are measured with the optical laser-Doppler-velocimetry technique. Thermographic measurements are applied for temperature field visualisations

  3. Observations of solar flare transition zone plasmas from the Solar Maximum Mission

    Science.gov (United States)

    Cheng, C.-C.; Bruner, E. C.; Tandberg-Hanssen, E.; Woodgate, B. E.; Shine, R. A.; Kenny, P. J.; Henze, W.; Poletto, G.

    1982-01-01

    The spatial and temporal evolution of the Si IV and O IV intensity, density and mass motions in preflare and flare transition zone plasmas are studied for the case of the April 8, 1980 flare. It is found that: (1) the UV flare observed in the Si IV and O IV lines is unambiguously identified as occurring in a low-lying, preexisting transition zone loop which spanned the magnetic neutral line separating a larger leader spot and a newly emerged, isolated spot of opposite polarity; (2) at the onset of the flare, the easternmost footpoint, which was anchored in an isolated spot region of high longitudinal magnetic field gradient, showed sudden, impulsive brightening with large intensity increases; and (3) the release flare energy was transported by way of large-scale connecting field lines to other parts of the active region, producing the hot plasma and H-alpha kernels observed near the trailing spot.

  4. Changes in melatonin secretion in tourists after rapid movement to another lighting zone without transition of time zone.

    Science.gov (United States)

    Wieczorek, Joanna; Blazejczyk, Krzysztof; Morita, Takeshi

    2016-01-01

    Most of the research in the field of Chronobiology is focused on the problem of the circadian rhythms (CR) desynchronization. In travelers, it results mostly from the changes of surrounding: photoperiod, local climate conditions (radiation and thermal load) and behavior (e.g. type and place of tourism and activity level). Until now, it was not documented whether the changes in melatonin (MLT) secretion occur in effect of mid-distance transparallel travels (TpT), without complications arising due to time-zone transitions (e.g. jet-lag syndrome). To cope with this problem, a special field experiment was carried out. In the experiment, MLT characteristics were examined twice a year in real conditions through a group of young tourists (23-26 years old) at their place of habitual residence (Warsaw, Poland), and at their tourist destination (Tromso, Norway). Transition to circumpolar zone in summer has resulted in insignificant reduction in melatonin peak value (MPV) compared to preflight control (2 days before travel) and the melatonin peak time (MPT) was delayed. However, after traveling southward on the returning flight, MPV was lower compared to control and MPT was advanced. In winter, MPV was insignificantly higher in comparison to preflight control and MPT was almost unchanged. While changes in MPV do not depend on season, flight direction and day of stay after flight than MPT was differentiated seasonally and due to direction of flight. MPV and MPT were significantly modified by characteristics of individual light exposure during daytime and evening. The experiment showed also that in real conditions activity level is an important factor affected melatonin peak in tourists. In winter, greater daytime activity significantly influenced earlier MPT occurrence, both after northward and southward flights.

  5. Global Discontinuity Structure of the Mantle Transition Zone from Finite-Frequency Tomography of SS Precursors

    Science.gov (United States)

    Guo, Z.; Zhou, Y.

    2017-12-01

    We report global structure of the 410-km and 660-km discontinuities from finite-frequency tomography using frequency-dependent traveltime measurements of SS precursors recorded at the Global Seismological Network (GSN). Finite-frequency sensitivity kernels for discontinuity depth perturbations are calculated in the framework of traveling-wave mode coupling. We parametrize the global discontinuities using a set of spherical triangular grid points and solve the tomographic inverse problem based on singular value decomposition. Our global 410-km and 660-km discontinuity models reveal distinctly different characteristics beneath the oceans and subduction zones. In general, oceanic regions are associated with a thinner mantle transition zone and depth perturbations of the 410-km and 660-km discontinuities are anti-correlated, in agreement with a thermal origin and an overall warm and dry mantle beneath the oceans. The perturbations are not uniform throughout the oceans but show strong small-scale variations, indicating complex processes in the mantle transition zone. In major subduction zones (except for South America where data coverage is sparse), depth perturbations of the 410-km and 660-km discontinuities are correlated, with both the 410-km and the 660-km discontinuities occurring at greater depths. The distributions of the anomalies are consistent with cold stagnant slabs just above the 660-km discontinuity and ascending return flows in a superadiabatic upper mantle.

  6. Supercritical fluid in the mantle transition zone deduced from H-D interdiffusion of wadsleyite

    Science.gov (United States)

    Sun, Wei; Yoshino, Takashi; Sakamoto, Naoya; Yurimoto, Hisayoshi

    2018-02-01

    Knowledge of the distribution of water in the Earth's mantle is key to understanding the mantle convection and geochemical evolution of the Earth. As wadsleyite and ringwoodite can incorporate large amounts of water in their crystal structures, proton conduction has been invoked to account for the widespread conductive anomalies observed in the mantle wedge, where descending slab stagnates at the transition zone. However, there is a lot of controversy on whether proton conduction by itself is able to explain such anomalies, because of large discrepancy in the extent of the water effect deduced from previous electrical conductivity measurements on hydrous polycrystalline wadsleyite and ringwoodite. Here we report the hydrogen self-diffusion coefficient obtained from H-D interdiffusion experiments in wadsleyite single-crystal couples. Our results demonstrate that the effect of water on the electrical conductivity of wadsleyite is limited and hydrous wadsleyite by itself is unable to explain conductive anomalies in the transition zone. In contrast, the expected hydrogen effective diffusion does not allow the wide propagation of water between the stagnant slab and surrounding mantle, probably leading to persistence of local water saturation and continuous release of supercritical fluids at the stagnant slab roof on geological time scales. This phenomenon provides an alternative explanation for both the high-conductivity and seismic-velocity anomalies observed in the mantle wedge at the transition-zone depth.

  7. Dynamics of the transition zone in coastal zone color scanner-sensed ocean color in the North Pacific during oceanographic spring

    Science.gov (United States)

    Glover, David M.; Wroblewski, J. S.; Mcclain, Charles R.

    1994-01-01

    A transition zone in phytoplankton concentration running across the North Pacific basin at 30 deg to 40 deg north latitude corresponds to a basin-wide front in surface chlorophyll observed in a composite of coastal zone color scanner (CZCS) images for May, June, and July 1979-1986. This transition zone with low chlorophyll to the south and higher chlorophyll to the north can be simulated by a simple model of the concentration of phytoplankton, zooplankton, and dissolved nutrient (nitrate) in the surface mixed layer of the ocean applied to the North Pacific basin for the climatological conditions during oceanographic springtime (May, June, and July). The model is initialized with a 1 deg x 1 deg gridded estimate of wintertime (February, March, and April) mixed layer nitrate concentrations calculated from an extensive nutrient database and a similarly gridded mixed layer depth data set. Comparison of model predictions with CZCS data provides a means of evaluating the dynamics of the transition zone. We conclude that in the North Pacific, away from major boundary currents and coastal upwelling zones, wintertime vertical mixing determines the total nutrient available to the plankton ecosystem in the spring. The transition zone seen in basin-scale CZCS images is a reflection of the geographic variation in the wintertime mixed layer depth and the nitracline, leading to a latitudinal gradient in phytoplankton chlorophyll.

  8. Small-scale spatial variability of phenoxy acid mineralization potentials in transition zones with a multidisciplinary approach

    DEFF Research Database (Denmark)

    Pazarbasi, Meric Batioglu

    The phenoxy acid group of herbicides is widely used to control broadleaf weeds, and it contaminates groundwater and surface water by leaching from agricultural soil or landfills. Due to the distinct vertical and horizontal gradients in nutrients and hydrologic exchange in transition zones...... in two transition zones, (1) the interfaces of unsaturated and saturated zones and (2) groundwater and surface water. Small-scale spatial variability of phenoxy acids was previously shown in topsoil; however, such small-scale studies are scarce in subsurface environments. We therefore studied the factors...... classes in the different mineralization potentials of discharge zones. Understanding of the natural attenuation potential of groundwater-surface water transition zones is important for stream water protection. In landfill-impacted groundwater-surface water interface, we further analyzed bacterial...

  9. Steady flows in the chromosphere and transition-zone above active regions as observed by OSO-8

    Science.gov (United States)

    Lites, B. W.

    1980-01-01

    Two years of data from the University of Colorado ultraviolet spectrometer aboard OSO-8 were searched for steady line-of-sight flows in the chromosphere and transition-zone above active regions. The most conspicuous pattern that emerges from this data set is that many sunspots show persistent blueshifts of transition-zone lines indicating velocities of about 20 km/s with respect to the surrounding plage areas. The data show much smaller shifts in ultraviolet emission lines arising from the chromosphere: the shifts are frequently to the blue, but sometimes redshifts do occur. Plage areas often show a redshift of the transition-zone lines relative to the surrounding quiet areas, and a strong gradient of the vertical component of the velocity is evident in many plages. One area of persistent blueshift was observed in the transition-zone above an active region filament. The energy requirement of these steady flows over sunspots is discussed.

  10. High Resolution Seismic Images of Transition Zone Discontinuities beneath the Hawaii-Emperor Seamount Chain

    Science.gov (United States)

    Cao, Q.; Wang, P.; van der Hilst, R. D.; Shim, S.

    2009-12-01

    Taking advantage of the abundance of natural sources (earthquakes) in western Pacific subduction zones and the many seismograph stations in the Americas, we use inverse scattering - a generalized Radon transform - of SS precursors to image the transition zone discontinuities underneath Hawaii and the Hawaii-Emperor seamount chain. The GRT makes use of scattering theory and extracts structural information from broad band data windows that include precursors to SS (which are the specular reflections at the discontinuities that form the main arrivals) as well as non-specular scattered energy (which is often discarded as noise). More than 150,000 seismograms (from the IRIS Data Management Center) are used to form a 3-D image of the transition zone discontinuities beneath the central Pacific. In addition to clear signals near 410, 520, and 660 km depth, the data also reveal scatter interfaces near 370 km dept and between 800-1000 km depth, which may be regional, laterally intermittent scatter horizons. Our images reveal a conspicuous uplift of the 660 discontinuity in a region of 800km in diameter to the west of the active volcanoes of Hawaii. No correspondent localized depression of the 410 discontinuity is found. Instead, we find a smaller scale anomaly suggesting that the 410 discontinuity is locally elevated in the same region. This may indicate the presence of melt or minor chemical constitutes. The lack of correlation between and differences in lateral length scale of the topographies of the 410 and 660 km discontinuities are also consistent with a deep-mantle plume impinging on the transition zone, creating a pond of hot material underneath 660 discontinuity, and with secondary plumes connecting to the present-day hotspot at Earth’s surface. Our observations suggest that more complicated plume morphology and plume dynamics within the Earth's mantle should be taken into account to describe the plumes and, in particular, mass transport across the transition zone

  11. High-Resolution P'P' Precursor Imaging of Nazca-South America Plate Boundary Zones and Inferences for Transition Zone Temperature and Composition

    Science.gov (United States)

    Gu, Y. J.; Schultz, R.

    2013-12-01

    Knowledge of upper mantle transition zone stratification and composition is highly dependent on our ability to efficiently extract and properly interpret small seismic arrivals. A promising high-frequency seismic phase group particularly suitable for a global analysis is P'P' precursors, which are capable of resolving mantle structures at vertical and lateral resolution of approximately 5 and 200 km, respectively, owing to their shallow incidence angle and small, quasi-symmetric Fresnel zones. This study presents a simultaneous analysis of SS and P'P' precursors based on deconvolution, Radon transform and depth migration. Our multi-resolution survey of the mantle near Nazca-South America subduction zone reveals both olivine and garnet related transitions at depth below 400 km. We attribute a depressed 660 to thermal variations, whereas compositional variations atop the upper-mantle transition zone are needed to explain the diminished or highly complex reflected/scattered signals from the 410 km discontinuity. We also observe prominent P'P' reflections within the transition zone, especially near the plate boundary zone where anomalously high reflection amplitudes result from a sharp (~10 km thick) mineral phase change resonant with the dominant frequency of the P'P' precursors. Near the base of the upper mantle, the migration of SS precursors shows no evidence of split reflections near the 660-km discontinuity, but potential majorite-ilmenite (590-640 km) and ilmenite-perovskite transitions (740-750 km) are identified based on similarly processed high-frequency P'P' precursors. At nominal mantle temperatures these two phase changes may be seismically indistinguishable, but colder mantle conditions from the descending Nazca plate, the presence of water and variable Fe contents may cause sufficient separation for a reliable analysis. In addition, our preliminary results provide compelling evidence for multiple shallow lower-mantle reflections (at ~800 km) along the

  12. Using thermodynamic data to reproduce main seismic features of transition zone

    Science.gov (United States)

    Fomin, Ilya; Saukko, Anna; Edwards, Paul; Schiffer, Christian

    2016-04-01

    Most of the seismic tomography studies nowadays are based on comprehensive models with optimization of lots of parameters. These models are able to resolve very subtle features of the Earth's mantle, but the influence of each specific parameter is not seen directly. In our research we try to minimize the number of processed parameters to produce simple synthetic cases. The main goals of our model are to see how water content influences the depth of the transition zone, and if melting at the transition zone is plausible. We also attempt to see how water content and the presence of melts influence the signal strength of the transition zone in receiver functions. Our MATLAB-code calculates phase assemblage according to specific temperature and pressure within 2D numerical domain (e.g. 300x700 km). Phase properties are calculated with database of Stixrude and Lithgow-Bertelloni [2011], with corrections for water impact on elastic constants according to Liu et al., [2012]. We use the mantle phase composition 55% garnet and 45% olivine-polymorph, soliduses by Ohtani et al. [2004] and melt properties by Sakamaki et al. [2006]. These data are used to calculate seismic velocities and, furthermore, receiver functions with standard routines (e.g.[Schiffer et al., 2012]). Model predicts Vs within 5 to 5.5 km/s and Vp around 9.5-10 km/s within transition zone (Vp/Vs = 1.84-1.87), which is close to standard values. The presence of water enlarges the wadsleyite region, but also dampens the peak of receiver functions down to background level. Increase in water content causes melting at much shallower depths. Using a normal thermal gradient, we can get up to 10% of melt at depths around 390 km with 80% of water saturation, shown by a negative anomaly on receiver functions. This result is similar to data obtained for Afar Plateau [Thompson et al., 2015]. With cratonic thermal gradient, the olivine-wadsleyite transition and corresponding melt layer appear at depths around 350 km

  13. Identifying the transition to the maturation zone in three ecotypes of Arabidopsis thaliana roots.

    Science.gov (United States)

    Cajero Sánchez, Wendy; García-Ponce, Berenice; Sánchez, María de la Paz; Álvarez-Buylla, Elena R; Garay-Arroyo, Adriana

    2018-01-01

    The Arabidopsis thaliana (hereafter Arabidopsis) root has become a useful model for studying how organ morphogenesis emerge from the coordination and balance of cell proliferation and differentiation, as both processes may be observed and quantified in the root at different stages of development. Hence, being able to objectively identify and delimit the different stages of root development has been very important. Up to now, three different zones along the longitudinal axis of the primary root of Arabidopsis, have been identified: the root apical meristematic zone (RAM) with two domains [the proliferative (PD) and the transition domain (TD)], the elongation zone (EZ) and the maturation zone (MZ). We previously reported a method to quantify the length of the cells of the meristematic and the elongation zone, as well as the boundaries or transitions between the root domains along the growing part of the Arabidopsis root. In this study, we provide a more accurate criterion to identify the MZ. Traditionally, the transition between the EZ to the MZ has been established by the emergence of the first root-hair bulge in the epidermis, because this emergence coincides with cell maturation in this cell type. But we have found here that after the emergence of the first root-hair bulge some cells continue to elongate and we have confirmed this in three different Arabidopsis ecotypes. We established the limit between the EZ and the MZ by looking for the closest cortical cell with a longer length than the average cell length of 10 cells after the cortical cell closest to the epidermal cell with the first root-hair bulge in these three ecotypes. In Col-0 and Ws this cell is four cells above the one with the root hair bulge and, in the Ler ecotype, this cell is five cells above. To unambiguously identifying the site at which cells stop elongating and attain their final length and fate at the MZ, we propose to calculate the length of completely elongated cortical cells counting 10

  14. The constructed catchment Chicken Creek as Critical Zone Observatory under transition

    Science.gov (United States)

    Gerwin, Werner; Schaaf, Wolfgang; Elmer, Michael; Hinz, Christoph

    2014-05-01

    The constructed catchment Chicken Creek was established in 2005 as an experimental landscape laboratory for ecosystem research. The 6 ha area with clearly defined horizontal as well as vertical boundary conditions was left for an unrestricted primary succession. All Critical Zone elements are represented at this site, which allows the study of most processes occurring at the interface of bio-, pedo-, geo- and hydrosphere. It provides outstanding opportunities for investigating interactions and feedbacks between different evolving compartments during ecosystem development. The catchment is extensively instrumented since 2005 in order to detect transition stages of the ecosystem. Data recorded with a high spatial and temporal resolution include hydrological, geomorphological, pedological, limnological as well as biological parameters. In contrast to other Critical Zone Observatories, this site offers the unique situation of an early stage ecosystem with highly dynamic system properties. The first years of development were characterized by a fast formation of geomorphological structures due to massive erosion processes at the initially non-vegetated surface. Hydrological processes led to the establishment of a local groundwater body within 5 years. In the following years the influence of biological structures like vegetation patterns gained an increasing importance. Feedbacks between developing vegetation and e.g. hydrological features became more and more dominant. As a result, different phases of ecosystem development could be distinguished until now. This observatory offers manifold possibilities to identify and disentangle complex interactions between Critical Zone processes in situ under natural conditions. The originally low complexity of the system is growing with time facilitating the identification of influences of newly developing structures on system functions. Thus, it is possible to study effects of small-scale processes on the whole system at the

  15. Geology of the Terra Cimmeria-Utopia Planitia Highland Lowland Transitional Zone: Final Technical Approach and Scientific Results

    Science.gov (United States)

    Skinner, J. A., Jr.; Tanaka, K. L.

    2010-01-01

    The southern Utopia highland-lowland transitional zone extends from northern Terra Cimmeria to southern Utopia Planitia and contains broad, bench-like platforms with depressions, pitted cones, tholi, and lobate flows. The locally occurring geologic units and landforms contrast other transitional regions and record a spatially partitioned geologic history. We systematically delineated and described the geologic units and landforms of the southern Utopia-Cimmeria highland-lowland transitional zone for the production of a 1:1,000,000-scale geologic map (MTMs 10237, 15237, 20237, 10242, 15242, 20242, 10247, 15247, and 20247). Herein, we present technical and scientific results of this mapping project.

  16. C2 Domains as Protein-Protein Interaction Modules in the Ciliary Transition Zone

    Directory of Open Access Journals (Sweden)

    Kim Remans

    2014-07-01

    Full Text Available RPGR-interacting protein 1 (RPGRIP1 is mutated in the eye disease Leber congenital amaurosis (LCA and its structural homolog, RPGRIP1-like (RPGRIP1L, is mutated in many different ciliopathies. Both are multidomain proteins that are predicted to interact with retinitis pigmentosa G-protein regulator (RPGR. RPGR is mutated in X-linked retinitis pigmentosa and is located in photoreceptors and primary cilia. We solved the crystal structure of the complex between the RPGR-interacting domain (RID of RPGRIP1 and RPGR and demonstrate that RPGRIP1L binds to RPGR similarly. RPGRIP1 binding to RPGR affects the interaction with PDEδ, the cargo shuttling factor for prenylated ciliary proteins. RPGRIP1-RID is a C2 domain with a canonical β sandwich structure that does not bind Ca2+ and/or phospholipids and thus constitutes a unique type of protein-protein interaction module. Judging from the large number of C2 domains in most of the ciliary transition zone proteins identified thus far, the structure presented here seems to constitute a cilia-specific module that is present in multiprotein transition zone complexes.

  17. [Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia].

    Science.gov (United States)

    Schmidt-Mumm, Udo; Vargas Ríos, Orlando

    2012-03-01

    Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia. High Andean paramo ecosystems are an important water resource for many towns, and major cities in this region. The aquatic and wetland vegetation of different paramo lakes, pond, swamps and bogs was studied according to the classical phytosociological approach, which is based on homogenous stands, but excludes any border phenomena or transitional zone. The present research aimed at determining the aquatic and wetland vegetation along different moisture gradients. A total of 89 species in 30 transects were reported, of which Crassula venezuelensis, Carex honplandii, Callitriche nubigena, Eleocharis macrostachya, Ranunculus flagelliformis, R. nubigenus, Eleocharis stenocarpa, Galium ascendens y Alopecurus aequalis were present in more than one third of the transects. Numerical classification and indicator species analysis resulted in the definition of the next 18 communities: 1) Calamagrostis effusa, 2) Sphagnum cuspidatum, 3) Cyperus rufus, 4) Eleocharis stenocarpa, 5) Carex acutata, 6) Poa annua,7) Valeriana sp., 8) Ranunculus flagelliformis, 9) Carex bonplandii, 10) Festuca andicola. 11) Muhlenbergia fustigiata, 12) Elatine paramoana, 13) Isoëtes palmeri, 14) Crassula venezuelensis, 15) Lilaeopsis macloviana, 16) Callitriche nubigena, 17) Potamogeton paramoanus and 18) Potamogeton illinoensis. The ordination of communities reveals the presence of three different aquatic-terrestrial gradients which are related to the life form structure of species that characterized the various communities. We concluded that patchiness and heterogeneity of the vegetation is mainly the result of alterations caused by human activities (burning, cattle raise and material extraction for road and dam construction).

  18. Triplicated P-wave measurements for waveform tomography of the mantle transition zone

    Directory of Open Access Journals (Sweden)

    S. C. Stähler

    2012-11-01

    Full Text Available Triplicated body waves sample the mantle transition zone more extensively than any other wave type, and interact strongly with the discontinuities at 410 km and 660 km. Since the seismograms bear a strong imprint of these geodynamically interesting features, it is highly desirable to invert them for structure of the transition zone. This has rarely been attempted, due to a mismatch between the complex and band-limited data and the (ray-theoretical modelling methods. Here we present a data processing and modelling strategy to harness such broadband seismograms for finite-frequency tomography. We include triplicated P-waves (epicentral distance range between 14 and 30° across their entire broadband frequency range, for both deep and shallow sources. We show that is it possible to predict the complex sequence of arrivals in these seismograms, but only after a careful effort to estimate source time functions and other source parameters from data, variables that strongly influence the waveforms. Modelled and observed waveforms then yield decent cross-correlation fits, from which we measure finite-frequency traveltime anomalies. We discuss two such data sets, for North America and Europe, and conclude that their signal quality and azimuthal coverage should be adequate for tomographic inversion. In order to compute sensitivity kernels at the pertinent high body wave frequencies, we use fully numerical forward modelling of the seismic wavefield through a spherically symmetric Earth.

  19. Functional Connectivity of Precipitation Networks in the Brazilian Rainforest-Savanna Transition Zone

    Science.gov (United States)

    Adera, S.; Larsen, L.; Levy, M. C.; Thompson, S. E.

    2016-12-01

    In the Brazilian rainforest-savanna transition zone, vegetation change has the potential to significantly affect precipitation patterns. Deforestation, in particular, can affect precipitation patterns by increasing land surface albedo, increasing aerosol loading to the atmosphere, changing land surface roughness, and reducing transpiration. Understanding land surface-precipitation couplings in this region is important not only for sustaining Amazon and Cerrado ecosystems, but also for cattle ranching and agriculture, hydropower generation, and drinking water management. Simulations suggest complex, scale-dependent interactions between precipitation and land cover. For example, the size and distribution of deforested patches has been found to affect precipitation patterns. We take an empirical approach to ask: (1) what are the dominant spatial and temporal length scales of precipitation coupling in the Brazilian rainforest-savanna transition zone? (2) How do these length scales change over time? (3) How does the connectivity of precipitation change over time? The answers to these questions will help address fundamental questions about the impacts of deforestation on precipitation. We use rain gauge data from 1100 rain gauges intermittently covering the period 1980 - 2013, a period of intensive land cover change in the region. The dominant spatial and temporal length scales of precipitation coupling are resolved using transfer entropy, a metric from information theory. Connectivity of the emergent network of couplings is quantified using network statistics. Analyses using transfer entropy and network statistics reveal the spatial and temporal interdependencies of rainfall events occurring in different parts of the study domain.

  20. Hybridization between mouse lemurs in an ecological transition zone in southern Madagascar.

    Science.gov (United States)

    Gligor, M; Ganzhorn, J U; Rakotondravony, D; Ramilijaona, O R; Razafimahatratra, E; Zischler, H; Hapke, A

    2009-02-01

    Hybrid zones in ecotones can be useful model systems for the study of evolutionary processes that shape the distribution and discreteness of species. Such studies could be important for an improved understanding of the complex biogeography of Madagascar, which is renowned for its outstanding degree of small-scale endemism. Certain forest remnants in central Madagascar indicate that transitional corridors across the island could have connected microendemics in different forest types in the past. Evolutionary processes in such corridors are difficult to study because most of these corridors have disappeared due to deforestation in central Madagascar. We studied a hybrid zone in one of the few remaining ecotonal corridors between dry and humid forests in Madagascar, which connects two species of mouse lemurs, Microcebus griseorufus in dry spiny forest and Microcebus murinus in humid littoral forest. We sampled 162 mouse lemurs at nine sites across this boundary. Morphometric analyses revealed intermediate morphotypes of many individuals in transitional habitat. Bayesian clustering of microsatellite genotypes and assignment tests yielded evidence for a mixed ancestry of mouse lemurs in the ecotone, where we also observed significant linkage disequilibria and heterozygote deficiency. In contrast to these observations, mitochondrial haplotypes displayed a sharply delimited boundary at the eastern edge of spiny forest, which was noncoincident with the signals from microsatellite data. Among several alternative scenarios, we propose asymmetric nuclear introgression due to male-biased dispersal, divergent environmental selection, and an expansion of dry spiny forest in the course of aridification as a probable explanation of our observations.

  1. Interpreting Brightness Asymmetries in Transition Disks: Vortex at Dead Zone or Planet-carved Gap Edges?

    Science.gov (United States)

    Regály, Zs.; Juhász, A.; Nehéz, D.

    2017-12-01

    Recent submillimeter observations show nonaxisymmetric brightness distributions with a horseshoe-like morphology for more than a dozen transition disks. The most-accepted explanation for the observed asymmetries is the accumulation of dust in large-scale vortices. Protoplanetary disks’ vortices can form by the excitation of Rossby wave instability in the vicinity of a steep pressure gradient, which can develop at the edges of a giant planet–carved gap or at the edges of an accretionally inactive zone. We studied the formation and evolution of vortices formed in these two distinct scenarios by means of two-dimensional locally isothermal hydrodynamic simulations. We found that the vortex formed at the edge of a planetary gap is short-lived, unless the disk is nearly inviscid. In contrast, the vortex formed at the outer edge of a dead zone is long-lived. The vortex morphology can be significantly different in the two scenarios: the vortex radial and azimuthal extensions are ∼1.5 and ∼3.5 times larger for the dead-zone edge compared to gap models. In some particular cases, the vortex aspect ratios can be similar in the two scenarios; however, the vortex azimuthal extensions can be used to distinguish the vortex formation mechanisms. We calculated predictions for vortex observability in the submillimeter continuum with ALMA. We found that the azimuthal and radial extent of the brightness asymmetry correlates with the vortex formation process within the limitations of α-viscosity prescription.

  2. Afferent and Efferent Connections of the Cortex-Amygdala Transition Zone in Mice.

    Science.gov (United States)

    Cádiz-Moretti, Bernardita; Abellán-Álvaro, María; Pardo-Bellver, Cecília; Martínez-García, Fernando; Lanuza, Enrique

    2016-01-01

    The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that the CxA receives a relatively restricted set of intratelencephalic connections, originated mainly by the olfactory system and basal forebrain, with minor afferents from the amygdala. The only relevant extratelencephalic afference originates in the ventral tegmental area (VTA). The efferent projections of the CxA reciprocate the inputs from the piriform cortex and olfactory amygdala. In addition, the CxA projects densely to the basolateral amygdaloid nucleus and the olfactory tubercle. The extratelencephalic projections of the CxA are very scarce, and target mainly hypothalamic structures. The pattern of connections of the CxA suggests that it is indeed a transitional area between the piriform cortex and the cortical amygdala. Double labeling with choline acetyltransferase indicates that the afferent projection from the basal forebrain is the origin of its distinctive cholinergic innervation, and double labeling with dopamine transporter shows that the projection from the VTA is the source of dopaminergic innervation. These connectivity and neurochemical features, together with the fact that it receives vomeronasal in addition to olfactory information, suggest that the CxA may be involved in processing olfactory information endowed with relevant biological meaning, such as odors

  3. Grain growth kinetics of ringwoodite and majorite garnet mixtures and implications for the rheology of the transition zone

    Science.gov (United States)

    Ezad, I.; Dobson, D. P.; Brodholt, J. P.; Thomson, A.; Hunt, S.

    2017-12-01

    The grain size of the transition zone is a poorly known but important geophysical parameter. Among others, the grain size may control the rheology, seismic attenuation and radiative thermal conductivity of the mantle. However, the grain size of the transition zone minerals ringwoodite (Mg,Fe)2SiO4 and majorite garnet MgSiO3 under appropriate zone conditions is currently unknown and there are very few experiments with which to constrain it. In order to determine the grain size of the transition zone, the grain growth kinetics must be determined for a range of mantle compositions. We have, therefore, experimentally determined the grain growth kinetics of the lowermost transition zone minerals through multi anvil experiments at University College London (UCL). This is achieved through a comprehensive set of time series experiments at pressures of 21 GPa and temperatures relevant to the transition zone. We have also determined the effect of varying water content, oxygen fugacity, iron content and aluminium content also discussed by Dobson and Mariani., (2014). Our initial grain growth experiments conducted at 1200°C and 1400°C at 18 GPa show extremely slow grain growth kinetics; time series experiments extended to 105.8 seconds are unable to produce grains larger than 100 nm. This suggests that fine-grained material at the base of the transition zone will persist on geological timescales. Such small grains size suggests that diffusion creep might be the dominant deformation mechanism in this region. Reference: Dobson, D.P., Mariani, E., 2014. The kinetics of the reaction of majorite plus ferropericlase to ringwoodite: Implications for mantle upwellings crossing the 660 km discontinuity. Earth Planet. Sci. Lett. 408, 110-118. doi:10.1016/j.epsl.2014.10.009

  4. Effects of Atlantic warm pool variability over climate of South America tropical transition zone

    Science.gov (United States)

    Ricaurte Villota, Constanza; Romero-Rodríguez, Deisy; Andrés Ordoñez-Zuñiga, Silvio; Murcia-Riaño, Magnolia; Coca-Domínguez, Oswaldo

    2016-04-01

    Colombia is located in the northwestern corner of South America in a climatically complex region due to the influence processes modulators of climate both the Pacific and Atlantic region, becoming in a transition zone between phenomena of northern and southern hemisphere. Variations in the climatic conditions of this region, especially rainfall, have been attributed to the influence of the El Nino Southern Oscillation (ENSO), but little is known about the interaction within Atlantic Ocean and specifically Caribbean Sea with the environmental conditions of this region. In this work We studied the influence of the Atlantic Warm Pool (AWP) on the Colombian Caribbean (CC) climate using data of Sea Surface Temperature (SST) between 1900 - 2014 from ERSST V4, compared with in situ data SIMAC (National System for Coral Reef Monitoring in Colombia - INVEMAR), rainfall between 1953-2013 of meteorological stations located at main airports in the Colombian Caribbean zone, administered by IDEAM, and winds data between 2003 - 2014 from WindSat sensor. The parameters analyzed showed spatial differences throughout the study area. SST anomalies, representing the variability of the AWP, showed to be associated with Multidecadal Atlantic Oscillation (AMO) and with the index of sea surface temperature of the North-tropical Atlantic (NTA), the variations was on 3 to 5 years on the ENSO scale and of approximately 11 years possibly related to solar cycles. Rainfall anomalies in the central and northern CC respond to changes in SST, while in the south zone these are not fully engage and show a high relationship with the ENSO. Finally, the winds also respond to changes in SST and showed a signal approximately 90 days possibly related to the Madden-Julian Oscillation, whose intensity depends on the CC region being analyzed. The results confirm that region is a transition zone in which operate several forcing, the variability of climate conditions is difficult to attribute only one, as ENSO

  5. Small Effect of Hydration on Elastic Wave Velocities of Ringwoodite in Earth's Transition Zone

    Science.gov (United States)

    Schulze, K.; Marquardt, H.; Boffa Ballaran, T.; Kurnosov, A.; Kawazoe, T.; Koch-Müller, M.

    2017-12-01

    Ringwoodite can incorporate significant amounts of hydrogen as OH-defects into its crystal structure. The measurement of 1.4 wt.% H20 in a natural ringwoodite diamond inclusion (Pearson et al. 2014) showed that hydrous ringwoodite can exist in the Earth's mantle. Since ringwoodite is considered to be the major phase in the mantle between 520 and 660 km depth it likely plays an important role for Earth's deep water cycle and the mantle water budget. Previous experimental work has shown that hydration reduces seismic wave velocities in ringwoodite, motivating attempts to map the hydration state of the mantle using seismic wave speed variations as depicted by seismic tomography. However, large uncertainties on the actual effects at transition zone pressures and temperatures remain. A major difficulty is the comparability of studies with different experimental setups and pressure- and temperature conditions. Here, we present results from a comparative elasticity study designed to quantify the effects of hydration on the seismic wave velocities of ringwoodite in Earth's transition zone. Focused ion beam cut single-crystals of four samples of either Fo90 or Fo100 ringwoodite with hydration states between 0.21 - 1.71 wt.% H2O were loaded in the pressure chamber of one diamond-anvil cell to ensure identical experimental conditions. Single-crystal Brillouin Spectroscopy and X-ray diffraction measurements were performed at room temperature to a pressure of 22 GPa. Additional experiments at high pressure and temperatures up to 500 K were performed. Our data collected at low pressures show a significant reduction of elastic wave velocities with hydration, consistent with previous work. However, in contrast to previous inferences, our results indicate that pressure significantly reduces the effect of hydration. Based on the outcome of our work, the redution in aggregate velocities caused by 1 wt.% H2O becomes smaller than 1% in ringwoodite at pressures equivalent to the Earth

  6. Water and Slabs in the Transition Zone - Hydrous Ringwoodite in Diamond

    Science.gov (United States)

    Pearson, D. G.; Brenker, F. E.; Nestola, F.; McNeill, J.; Nasdala, L.; Hutchison, M.; Matveev, S.; Mather, K.; Vincze, L.; Schmitz, S.; Vekemens, B.

    2014-12-01

    Theory and experiments have shown that the Earth's Transition Zone (TZ) could be a major repository for water, due to the ability of the higher-pressure polymorphs of olivine - wadsleyite and ringwoodite - to host up to ~2.5wt. % H2O. Despite experimental demonstration of the water-bearing capacity of these phases, geophysical probes such as electrical conductivity have provided conflicting results, and the issue of whether the TZ contains abundant water remains highly controversial. We report X-ray diffraction, Raman and infra-red spectroscopic evidence for the first terrestrial occurrence of any higher pressure polymorph of olivine: ringwoodite, included in a diamond from Juína, Brazil. The ringwoodite occurs with a Ca-walstromite phase that we interpret to be retrogressed Ca-silicate perovskite. The most likely interpretation of this two-phase assemblage is that it represents a partially retrogressed portion of a somewhat Fe-rich peridotitic mantle, in which hydrous ringwoodite, and former CaSiO3- perovskite co-existed above 15GPa. The ringwoodite has a Mg# of ~ 75, suggesting that it may be mantle hybrised with a more fertile component such as subducted oceanic crust. The water-rich nature of this inclusion (~1.5 wt%), along with the preservation of ringwoodite, is the first direct evidence that, at least locally, the TZ is hydrous, to about 1 wt%. As well as being in agreement with recent magnetotelluric estimates of the TZ water content, this amount of water helps to reconcile measured TZ seismic velocities with those predicted from lab experiments. The finding also indicates that some kimberlites must have their primary sources in this deep mantle region. The high water content of the ringwoodite suggests that it was not close to the mantle geotherm when trapped in the diamond. This may be an indication that the the assemblage was part of a water-rich subducted slab out of thermal equilibrium, within the transition zone. The water-rich nature of the

  7. Rifting-to-drifting transition of the South China Sea: Moho reflection characteristics in continental-ocean transition zone

    Science.gov (United States)

    Wen, Y.; Li, C.

    2017-12-01

    Dispute remains on the process of continental rifting to subsequent seafloor spreading in the South China Sea (SCS). Several crust-scale multi-channel seismic reflection profiles acquired in the continent-ocean transition zone (COT) of the SCS provide a detailed overview of Moho and deep crustal reflectors and give key information on rifting-to-drifting transition of the area. Moho has strong but discontinuous seismic reflection in COT. These discontinuities are mainly located in the landward side of continent-ocean boundary (COB), and may own to upwelling of lower crustal materials during initial continental extension, leading to numerous volcanic edifices and volcanic ridges. The continental crust in COT shows discontinuous Moho reflections at 11-8.5 s in two-way travel time (twtt), and thins from 18-20.5 km under the uppermost slope to 6-7 km under the lower slope, assuming an average crustal velocity of 6.0 km/s. The oceanic crust has Moho reflections of moderate to high continuity mostly at 1.8-2.2 s twtt below the top of the igneous basement, which means that the crustal thickness excluding sediment layer in COT is 5.4-6.6 km. Subhorizontal Moho reflections are often abruptly interrupted by large seaward dipping normal faults in southern COT but are more continuous compared with the fluctuant and very discontinuous Moho reflections in northern COT. The thickness of thinned continental crust (4.2-4.8 km) is smaller than that of oceanic crust (5.4-6.0 km) near southern COB, indicating that the continental crust has experienced a long period of rifting before seafloor spreading started. The smaller width of northern COT (0-40 km) than in southern COT (0-60 km), and thinner continental crust in southern COT, all indicate that the continental margin rifting and extension was asymmetric. The COT width in the SCS is narrower than that found in other magma-poor continental margins, indicating a swift transition from the final stage of rifting to the inception of

  8. Prostate-specific membrane antigen PET/MRI validation of MR textural analysis for detection of transition zone prostate cancer.

    Science.gov (United States)

    Bates, Anthony; Miles, Kenneth

    2017-12-01

    To validate MR textural analysis (MRTA) for detection of transition zone (TZ) prostate cancer through comparison with co-registered prostate-specific membrane antigen (PSMA) PET-MR. Retrospective analysis was performed for 30 men who underwent simultaneous PSMA PET-MR imaging for staging of prostate cancer. Thirty texture features were derived from each manually contoured T2-weighted, transaxial, prostatic TZ using texture analysis software that applies a spatial band-pass filter and quantifies texture through histogram analysis. Texture features of the TZ were compared to PSMA expression on the corresponding PET images. The Benjamini-Hochberg correction controlled the false discovery rate at prostate cancer. • Prostate transition zone (TZ) MR texture analysis may assist in prostate cancer detection. • Abnormal transition zone PSMA expression correlates with altered texture on T2-weighted MR. • TZ with abnormal PSMA expression demonstrates significantly reduced MI, SD and MPP.

  9. Repeating Deep Very Low Frequency Earthquakes: An Evidence of Transition Zone between Brittle and Ductile Zone along Plate Boundary

    Science.gov (United States)

    Ishihara, Y.; Yamamoto, Y.; Arai, R.

    2017-12-01

    Recently slow or low frequency seismic and geodetic events are focused under recognition of important role in tectonic process. The most western region of Ryukyu trench, Yaeyama Islands, is very active area of these type events. It has semiannual-like slow slip (Heki et.al., 2008; Nishimura et.al.,2014) and very frequent shallow very low frequency earthquakes near trench zone (Ando et.al.,2012; Nakamura et.al.,2014). Arai et.al.(2016) identified clear reverse phase discontinuity along plate boundary by air-gun survey, suggesting existence of low velocity layer including fluid. The subducting fluid layer is considered to control slip characteristics. On the other hand, deep low frequency earthquake and tremor observed at south-western Honshu and Shikoku of Japan are not identified well due to lack of high-quality seismic network. A broadband seismic station(ISG/PS) of Pacific21 network is operating in last 20 years that locates on occurrence potential area of low frequency earthquake. We tried to review continuous broadband record, searching low frequency earthquakes. In pilot survey, we found three very low frequency seismic events which are dominant in less than 0.1Hz component and are not listed in earthquake catalogue. Source locates about 50km depth and at transition area between slow slip event and active area of general earthquake along plate boundary. To detect small and/or hidden very low frequency earthquake, we applied matched filter analysis to continuous three components waveform data using pre-reviewed seismogram as template signal. 12 events with high correlation are picked up in last 10 years. Most events have very similar waveform, which means characteristics of repeating deep very low frequency earthquake. The event history of very low frequency earthquake is not related with one of slow slip event in this region. In Yaeyama region, low frequency earthquake, general earthquake and slow slip event occur dividing in space and have apparent

  10. Zone 1 retinopathy of prematurity in a transitional economy: a cautionary note.

    Science.gov (United States)

    Carden, Susan M; Lan, Luu Ngoc; Huynh, Tess

    2006-06-01

    To describe three low risk infants in whom severe retinopathy of prematurity developed. A prospective, observational case series. setting: National Hospital of Pediatrics, Hanoi, Vietnam. study population: Premature infants in the neonatal ward. observation procedure: Eye examinations. Severe retinopathy of prematurity occurred in three infants. All had zone 1 disease and other unusually severe findings, such as neovascularization of the disk. These infants would not be at risk for the development of such severe retinopathy of prematurity in countries with a developed economy. Unusual characteristics of retinopathy of prematurity may be occurring in countries with transitional economies. Screening programs should be implemented and should take into consideration the possibility that retinopathy of prematurity may occur in infants who fall outside the screening guidelines that are used in the developed world.

  11. Influence of compaction on the interfacial transition zone and the permeability of concrete

    International Nuclear Information System (INIS)

    Leemann, Andreas; Muench, Beat; Gasser, Philippe; Holzer, Lorenz

    2006-01-01

    The interfacial transition zone (ITZ) is regarded as a key feature for the transport properties and the durability of concrete. In this study one self-compacting concrete (SCC) mixture and two conventionally vibrated concrete (CVC) mixtures are studied in order to determine the influence of compaction on the porosity of the ITZ. Additionally oxygen permeability and water conductivity were measured in vertical and horizontal direction. The quantitative analysis of images made with an optical microscope and an environmental scanning electron microscope shows a significantly increased porosity and width of the ITZ in CVC compared to SCC. At the same time oxygen permeability and water conductivity of CVC are increased in comparison to SCC. Moreover, considerable differences in the porosity of the lower, lateral and upper ITZ are observed in both types of concrete. The anisotropic distribution of pores in the ITZ does not necessarily cause anisotropy in oxygen permeability and water conductivity though

  12. Micromechanical performance of interfacial transition zone in fiber-reinforced cement matrix

    Science.gov (United States)

    Zacharda, V.; Němeček, J.; Štemberk, P.

    2017-09-01

    The paper investigates microstructure, chemical composition and micromechanical behavior of an interfacial transition zone (ITZ) in steel fiber reinforced cement matrix. For this goal, a combination of scanning electron microscopy (SEM), nanoindentation and elastic homogenization theory are used. The investigated sample of cement paste with dispersed reinforcement consists of cement CEM I 42,5R and a steel fiber TriTreg 50 mm. The microscopy revealed smaller portion of clinkers and larger porosity in the ITZ. Nanoindentation delivered decreased elastic modulus in comparison with cement bulk (67%) and the width of ITZ (∼ 40 μm). The measured properties served as input parameters for a simple two-scale model for elastic properties of the composite. Although, no major influence of ITZ properties on the composite elastic behavior was found, the findings about the ITZ reduced properties and its size can serve as input to other microstructural fracture based models.

  13. PWR steam generators tube integrity: plugging criteria for PWSCC in roll transition zone

    International Nuclear Information System (INIS)

    Mattar Neto, Miguel; Cruz, Julio R.B.

    1999-01-01

    One of the most important causes for tube plugging in PWR (Pressurized Water Reactor) steam generators is the degradation mechanism called Primary Water Stress Corrosion Cracking (PWSCC) in roll transition zone (RTZ) near the tubesheet, mainly for Alloy 600 tubes. To avoid an excessive tube plugging, alternative criteria have been developed based on an approach that consists in withdrawing from service any tube containing a defect for which there is a high probability of a critical size under accident conditions to be reached during next operation cycle. Predictions of the number of tubes to be plugged can be done aiming at preventive maintenance and tube repair, and even a steam generator replacement, without a large and non-planned plant outage. This work presents important aspects related to tube plugging criteria for PWSCC in RTZ based on the risk of break after a leak detection. Calculations of allowable crack length and allowable leak rate for a particular situation are also shown. (author)

  14. Transition-zone observations of rapid flare events as observed by OSO-8

    Science.gov (United States)

    Lites, B. W.

    1981-01-01

    The rapid dissipation of flare energy has been observed in the transition-zone line of C IV at 1548.2 A using the University of Colorado spectrometer aboard OSO-8. Impulsive brightenings have been resolved with characteristic rise times as low as 3.5s. One event is analyzed in detail, and it is inferred that the electron density is greater than 2 x 10 to the 11th/cu cm at a temperature of 60,000 K, and that the flare energy is deposited at a rate of 2 ergs/cu cm per sec or greater. The temporal behavior of the intensity at the center of the C IV line is consistent with a nonequilibrium ionization of C III through C V. If this event is a result of the multiple tearing mode instability as the primary energy release mechanism, then the observations indicate a preflare magnetic field of about 175 G.

  15. Performance Analysis of a Recycled Concrete Interfacial Transition Zone in a Rapid Carbonization Environment

    Directory of Open Access Journals (Sweden)

    Gongbing Yue

    2018-01-01

    Full Text Available Based on the characteristics of recycled concrete interface structures, a multi-interface reconstruction model was established. To study the microstructure evolution of the interfacial transition zone (ITZ during the carbonization process of recycled concrete, the microstructure characteristics of the ITZ of C30, C40, and C50 grade recycled concrete and the mortar matrix before and after carbonization were studied through the microhardness tester and SEM. The results show that the microhardness values of the ITZ and the mortar matrix are obviously increased and that the width of the ITZ decreases, while the ITZ performance of the C50 grade recycled concrete is not significantly changed. The ITZ exhibits a large amount of granular CaCO3 after carbonization, the pores are refined, and microcracks are generated. Overall, there are significant differences in the microstructures between the ITZ and the mortar matrix before and after carbonization.

  16. Dynamic Linkages Between the Transition Zone & Surface Plate Motions in 2D Models of Subduction

    Science.gov (United States)

    Arredondo, K.; Billen, M. I.

    2013-12-01

    While slab pull is considered the dominant force controlling plate motion and speed, its magnitude is controlled by slab behavior in the mantle, where tomographic studies show a wide range of possibilities from direct penetration to folding, or stagnation directly above the lower mantle (e.g. Fukao et al., 2009). Geodynamic studies have investigated various parameters, such as plate age and two phase transitions, to recreate observed behavior (e.g. Běhounková and Cízková, 2008). However, past geodynamic models have left out known slab characteristics that may have a large impact on slab behavior and our understanding of subduction processes. Mineral experiments and seismic observations have indicated the existence of additional phase transitions in the mantle transition zone that may produce buoyancy forces large enough to affect the descent of a subducting slab (e.g. Ricard et al., 2005). The current study systematically tests different common assumptions used in geodynamic models: kinematic versus free-slip boundary conditions, the effects of adiabatic heating, viscous dissipation and latent heat, compositional layering and a more complete suite of phase transitions. Final models have a complete energy equation, with eclogite, harzburgite and pyrolite lithosphere compositional layers, and seven composition-dependent phase transitions within the olivine, pyroxene and garnet polymorph minerals. Results show important feedback loops between different assumptions and new behavior from the most complete models. Kinematic models show slab weakening or breaking above the 660 km boundary and between compositional layers. The behavior in dynamic models with a free-moving trench and overriding plate is compared to the more commonly found kinematic models. The new behavior may have important implications for the depth distribution of deep earthquakes within the slab. Though the thermodynamic parameters of certain phase transitions may be uncertain, their presence and

  17. DEEP STRUCTURE OF THE SIBERIAN PLATFORM – CENTRAL ASIAN MOBILE BELT TRANSITION ZONE FROM TELESEISMIC DATA

    Directory of Open Access Journals (Sweden)

    V. V. Mordvinova

    2016-01-01

    Full Text Available Deep velocity sections of the transition zone from the Siberian platform to the Central Asian mobile belt are constructed by teleseismic tomography and P-receiver function techniques. An array of the dense ancient Siberian craton is identified in the velocity sections with areas of high seismic velocity. In the SSW section MOBAL_2003, the surface boundary of the craton corresponds to the southern margin of the Siberian platform and is nearly vertical to a depth of 120 km. At larger depths, the craton slides almost horizontally underneath the Tunka rift area. At depths from 150 to 250 km, it is in contact with the area under the Khamar-Daban mountain range. In the southeast, according to the SE velocity section PASSCAL_1992 across the South Baikal basin and the Khamar-Daban mountain range, the Siberian craton thickness is reduced from 270 to 150 km at the contact of the Siberian platform with the Baikal folded area. In this contact zone, the upper part of the craton is wedge-shaped and has an angle of about 45° with the ground surface; it completely tapers off at a depth of 150 km to the east of Lake Baikal. The vertical configuration of the southern segment of the Siberian craton, which evolved with time, may determine the nature of the Baikal rifting in the Cenozoic. 

  18. Observed Spectral Invariant Behavior of Zenith Radiance in the Transition Zone Between Cloud-Free and Cloudy Regions

    Science.gov (United States)

    Marshak, A.; Knyazikhin, Y.; Chiu, C.; Wiscombe, W.

    2010-01-01

    The Atmospheric Radiation Measurement Program's (ARM) new Shortwave Spectrometer (SWS) looks straight up and measures zenith radiance at 418 wavelengths between 350 and 2200 nm. Because of its 1-sec sampling resolution, the SWS provides a unique capability to study the transition zone between cloudy and clear sky areas. A surprising spectral invariant behavior is found between ratios of zenith radiance spectra during the transition from cloudy to cloud-free atmosphere. This behavior suggests that the spectral signature of the transition zone is a linear mixture between the two extremes (definitely cloudy and definitely clear). The weighting function of the linear mixture is found to be a wavelength-independent characteristic of the transition zone. It is shown that the transition zone spectrum is fully determined by this function and zenith radiance spectra of clear and cloudy regions. This new finding may help us to better understand and quantify such physical phenomena as humidification of aerosols in the relatively moist cloud environment and evaporation and activation of cloud droplets.

  19. How Models Simulate the Radiative Effect in the Transition Zone of the Aerosol-Cloud Continuum

    Science.gov (United States)

    Calbo Angrill, J.; González, J. A.; Long, C. N.; McComiskey, A. C.

    2017-12-01

    Several studies have pointed towards dealing with clouds and aerosols as two manifestations of what is essentially the same physical phenomenon: a suspension of tiny particles in the air. Although the two extreme cases (i.e., pure aerosol and well-defined cloud) are easily distinguished, and obviously produce different radiative effects, there are many situations in the transition (or "twilight") zone. In a recent paper [Calbó et al., Atmos. Res. 2017, j.atmosres.2017.06.010], the authors of the current communication estimated that about 10% of time there might be a suspension of particles in the air that is difficult to distinguish as either cloud or aerosol. Radiative transfer models, however, simulate the effect of clouds and aerosols with different modules, routines, or parameterizations. In this study, we apply a sensitivity analysis approach to assess the ability of two radiative transfer models (SBDART and RRTM) in simulating the radiative effect of a suspension of particles with characteristics in the boundary between cloud and aerosol. We simulate this kind of suspension either in "cloud mode" or in "aerosol mode" and setting different values of optical depth, droplet size, water path, aerosol type, cloud height, etc. Irradiances both for solar and infrared bands are studied, both at ground level and at the top of the atmosphere, and all analyses are repeated for different solar zenith angles. We obtain that (a) water clouds and ice clouds have similar radiative effects if they have the same optical depth; (b) the spread of effects regarding different aerosol type/aerosol characteristics is remarkable; (c) radiative effects of an aerosol layer and of a cloud layer are different, even if they have similar optical depth; (d) for a given effect on the diffuse component, the effect on the direct component is usually greater (more extinction of direct beam) by aerosols than by clouds; (e) radiative transfer models are somewhat limited when simulating the

  20. Dynamic recrystallization mechanisms and their transition in the Daling Thrust (DT) zone, Darjeeling-Sikkim Himalaya

    Science.gov (United States)

    Ghosh, Subhajit; Bose, Santanu; Mandal, Nibir; Dasgupta, Sujoy

    2016-04-01

    The Daling Thrust (DT) delineates a zone of intense shear localization in the Lesser Himalayan Sequence (LHS) of the Darjeeling-Sikkim Himalaya. From microstructural studies of deformed quartzite samples, we show a transition in the dynamic recrystallization mechanism with increasing distance from the DT, dominated by grain boundary bulging (BLG) recrystallization closest to the DT, and progressively replaced by sub-grain rotation (SGR) recrystallization away from the thrust. The transition is marked by a characteristic variation in the fractal dimension (D) of grain boundaries, estimated from the area-perimeter method. For the BLG regime, D ≈ 1.046, which decreases significantly to a value as low as 1.025 for the SGR regime. Using the available thermal data for BLG and SGR recrystallization, we infer increasing deformation temperatures away from the DT in the hanging wall. Based on the quartz piezometer our estimates reveal strong variations in the flow stress (59.00 MPa to 16.00 MPa) over a distance of 1.2 km from the DT. Deformation mechanism maps constructed for different temperatures indicate that the strain rates (10- 12 S- 1 to 10- 14 S- 1) comply with the geologically possible range. Finally, we present a mechanical model to provide a possible explanation for the cause of stress intensification along the DT.

  1. CATCHING QUENCHING GALAXIES: THE NATURE OF THE WISE INFRARED TRANSITION ZONE

    Energy Technology Data Exchange (ETDEWEB)

    Alatalo, Katherine; Appleton, Philip N.; Rich, Jeffrey A. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Cales, Sabrina L. [Department of Astronomy, Faculty of Physical and Mathematical Sciences, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Kewley, Lisa J. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Lacy, Mark [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Lisenfeld, Ute [Departamento de Física Teórica y del Cosmos, Universidad de Granada, Granada (Spain); Nyland, Kristina, E-mail: kalatalo@caltech.edu [Physics Department, New Mexico Tech, Socorro, NM 87801 (United States)

    2014-10-10

    We present the discovery of a prominent bifurcation between early-type galaxies and late-type galaxies, in [4.6]-[12] μm colors from the Wide Field Infrared Survey Explorer (WISE). We then use an emission-line diagnostic comparison sample to explore the nature of objects found both within and near the edges of this WISE infrared transition zone (IRTZ). We hypothesize that this bifurcation might be due to the presence of hot dust and polyaromatic hydrocarbon (PAH) emission features in late-type galaxies. Using a sample of galaxies selected through the Shocked Poststarburst Galaxy Survey (SPOGS), we are able to identify galaxies with strong Balmer absorption (EW(Hδ) > 5 Å) as well as emission lines inconsistent with star formation (deemed SPOG candidates, or SPOGs*) that lie within the optical green valley. Seyferts and low-ionization nuclear emission line regions, whose u – r colors tend to be red, are strongly represented within IRTZ, whereas SPOGs* tend to sit near the star-forming edge. Although active galactic nuclei are well represented in the IRTZ, we argue that the dominant IRTZ population is composed of galaxies that are in late stages of transitioning across the optical green valley, shedding the last of their remnant interstellar media.

  2. Conjecture with water and rheological control for subducting slab in the mantle transition zone

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    Fumiko Tajima

    2015-01-01

    Full Text Available Seismic observations have shown structural variation near the base of the mantle transition zone (MTZ where subducted cold slabs, as visualized with high seismic speed anomalies (HSSAs, flatten to form stagnant slabs or sink further into the lower mantle. The different slab behaviors were also accompanied by variation of the “660 km” discontinuity depths and low viscosity layers (LVLs beneath the MTZ that are suggested by geoid inversion studies. We address that deep water transport by subducted slabs and dehydration from hydrous slabs could affect the physical properties of mantle minerals and govern slab dynamics. A systematic series of three-dimensional numerical simulation has been conducted to examine the effects of viscosity reduction or contrast between slab materials on slab behaviors near the base of the MTZ. We found that the viscosity reduction of subducted crustal material leads to a separation of crustal material from the slab main body and its transient stagnation in the MTZ. The once trapped crustal materials in the MTZ eventually sink into the lower mantle within 20–30 My from the start of the plate subduction. The results suggest crustal material recycle in the whole mantle that is consistent with evidence from mantle geochemistry as opposed to a two-layer mantle convection model. Because of the smaller capacity of water content in lower mantle minerals than in MTZ minerals, dehydration should occur at the phase transformation depth, ∼660 km. The variation of the discontinuity depths and highly localized low seismic speed anomaly (LSSA zones observed from seismic P waveforms in a relatively high frequency band (∼1 Hz support the hypothesis of dehydration from hydrous slabs at the phase boundary. The LSSAs which correspond to dehydration induced fluids are likely to be very local, given very small hydrogen (H+ diffusivity associated with subducted slabs. The image of such local LSSA zones embedded in HSSAs may not

  3. Deformation processes and weakening mechanisms within the frictional viscous transition zone of major crustal-scale faults: insights from the Great Glen Fault Zone, Scotland

    Science.gov (United States)

    Stewart, M.; Holdsworth, R. E.; Strachan, R. A.

    2000-05-01

    The Great Glen Fault Zone (GGFZ), Scotland, is a typical example of a crustal-scale, reactivated strike-slip fault within the continental crust. Analysis of intensely strained fault rocks from the core of the GGFZ near Fort William provides a unique insight into the nature of deformation associated with the main phase of (sinistral) movements along the fault zone. In this region, an exhumed sequence of complex mid-crustal deformation textures that developed in the region of the frictional-viscous transition (ca. 8-15 km depth) is preserved. Fault rock fabrics vary from mylonitic in quartzites to cataclastic in micaceous shear zones and feldspathic psammites. Protolith mineralogy exerted a strong control on the initial textural development and distribution of the fault rocks. At lower strains, crystal-plastic deformation occurred in quartz-dominated lithologies to produce mylonites simultaneously with widespread fracturing and cataclasis in feldspar- and mica-dominated rocks. At higher strains, shearing appears to increasingly localise into interconnected networks of cataclastic shear zones, many of which are strongly foliated. Textures indicative of fluid-assisted diffusive mass transfer mechanisms are widespread in such regions and suggest that a hydrous fluid-assisted, grainsize-controlled switch in deformation behaviour followed the brittle comminution of grains. The fault zone textural evolution implies that a strain-induced, fluid-assisted shallowing and narrowing of the frictional-viscous transition occurred with increasing strain. It is proposed that this led to an overall weakening of the fault zone and that equivalent processes may occur along many other long-lived, crustal-scale dislocations.

  4. Exploring the Cross-sectional Association between Transit-Oriented Development Zoning and Active Travel and Transit Usage in the United States, 2010-2014

    Directory of Open Access Journals (Sweden)

    Emily eThrun

    2016-06-01

    Full Text Available Background: In response to traditional zoning codes that contribute to car-dependent, sprawling, and disconnected neighborhoods, communities are reforming their land use laws to create pedestrian-friendly areas that promote physical activity. One such reform is the adoption of transit-oriented developments or districts (TODs. TODs are higher-density, compact, mixed use areas located around transit stops that are designed to encourage walking.Purpose: To identify the characteristics of communities that have adopted TODs in their land use laws and examine if communities that have included TODs in their zoning codes are more likely to have adults that commute by any form of active transportation (i.e., walking, biking, or public transportation or by using public transportation specifically.Methods: Zoning codes effective as of 2010 were obtained for a purposeful sample of the largest 3,914 municipal jurisdictions located in 473 of the most populous US counties and consolidated cities within 48 states and the District of Columbia. They were evaluated to determine whether they included TOD districts or regulations using a coding tool developed by the study team. Descriptive statistics together with t-tests and Pearson’s chi-squared independence test were used to compare characteristics of jurisdictions with and without TOD zoning. Multivariate linear regressions were used to compute the adjusted association between TOD zoning and taking public or active transportation to work.Results: Jurisdictions with TOD zoning were located more in the South and West than non-TOD jurisdictions and were more populous, higher income, more racially diverse, and younger. Jurisdictions with TOD zoning had significantly higher percentages of occupied housing with no vehicle than those without TOD zoning. TOD zoning was associated with significantly higher rates of public transportation to work (β=2.10, 95% CI=0.88, 3.32 and active transportation to work (β=2.48, 95

  5. Aggregate-cement paste transition zone properties affecting the salt-frost damage of high-performance concretes

    International Nuclear Information System (INIS)

    Cwirzen, Andrzej; Penttala, Vesa

    2005-01-01

    The influence of the cement paste-aggregate interfacial transition zone (ITZ) on the frost durability of high-performance silica fume concrete (HPSFC) has been studied. Investigation was carried out on eight non-air-entrained concretes having water-to-binder (W/B) ratios of 0.3, 0.35 and 0.42 and different additions of condensed silica fume. Studies on the microstructure and composition of the cement paste have been made by means of environmental scanning electron microscope (ESEM)-BSE, ESEM-EDX and mercury intrusion porosimetry (MIP) analysis. The results showed that the transition zone initiates and accelerates damaging mechanisms by enhancing movement of the pore solution within the concrete during freezing and thawing cycles. Cracks filled with ettringite were primarily formed in the ITZ. The test concretes having good frost-deicing salt durability featured a narrow transition zone and a decreased Ca/Si atomic ratio in the transition zone compared to the bulk cement paste. Moderate additions of silica fume seemed to densify the microstructure of the ITZ

  6. Earthworm activities in cassava and egusi melon fields in the transitional zone of Benin: linking farmers' perceptions with field studies

    NARCIS (Netherlands)

    Saïdou, A.; Kossou, D.; Brussaard, L.; Richards, P.; Kuyper, T.W.

    2008-01-01

    Farmers' perceptions of earthworm activities were studied in the transitional zone of Benin and linked to scientific explanations of earthworm casting activities. Earthworm activity was assessed in farmers' fields with three different cassava cultivars and in a field experiment with three different

  7. Migration agricole et usages durables de la terre dans la zone de transition forêt-savane (Ghana)

    NARCIS (Netherlands)

    van der Geest, K.

    2010-01-01

    Au Ghana, d’après des images satellites, la zone de transition entre la forêt et la savane a subi en trente ans une profonde dégradation environnementale. La forte immigration de cultivateurs du Haut Ghana occidental, accentuant une rapide croissance démographique, a accru la pression sur les

  8. Microphysical characteristics of squall-line stratiform precipitation and transition zones inferred using an ice particle property-evolving model

    Science.gov (United States)

    Jensen, A. A.; Harrington, J. Y.; Morrison, H.

    2017-12-01

    A quasi-idealized 3D squall line (based on a June 2007 Oklahoma case) is simulated using a novel bulk microphysics scheme called the Ice-Spheroids Habit Model with Aspect-ratio Evolution (ISHMAEL). In ISHMAEL, the evolution of ice particle properties, such as mass, shape, maximum diameter, density, and fall speed, are tracked as these properties evolve from vapor growth, sublimation, riming, and melting. Thus, ice properties evolve from various microphysical processes without needing separate unrimed and rimed ice categories. Simulation results show that ISHMAEL produces both a squall-line transition zone and an enhanced stratiform precipitation region. The ice particle properties produced in this simulation are analyzed and compared to observations to determine the characteristics of ice that lead to the development of these squall-line features. It is shown that rimed particles advected rearward from the convective region produce the enhanced stratiform precipitation region. The development of the transition zone results from hydrometer sorting: the evolution of ice particle properties in the convective region produces specific fall speeds that favor significant ice advecting rearward of the transition zone before reaching the melting level, causing a local minimum in precipitation rate and reflectivity there. Microphysical sensitivity studies, for example turning rime splintering off, that lead to changes in ice particle properties reveal that the fall speed of ice particles largely determines both the location of the enhanced stratiform precipitation region and whether or not a transition zone forms.

  9. Determinants of Transitional Zone Area and Porosity of the Proximal Femur Quantified In Vivo in Postmenopausal Women.

    Science.gov (United States)

    Shigdel, Rajesh; Osima, Marit; Lukic, Marko; Ahmed, Luai A; Joakimsen, Ragnar M; Eriksen, Erik F; Bjørnerem, Åshild

    2016-04-01

    Bone architecture as well as size and shape is important for bone strength and risk of fracture. Most bone loss is cortical and occurs by trabecularization of the inner part of the cortex. We therefore wanted to identify determinants of the bone architecture, especially the area and porosity of the transitional zone, an inner cortical region with a large surface/matrix volume available for intracortical remodeling. In 211 postmenopausal women aged 54 to 94 years with nonvertebral fractures and 232 controls from the Tromsø Study, Norway, we quantified femoral subtrochanteric architecture in CT images using StrAx1.0 software, and serum levels of bone turnover markers (BTM, procollagen type I N-terminal propeptide and C-terminal cross-linking telopeptide of type I collagen). Multivariable linear and logistic regression analyses were used to quantify associations of age, weight, height, and bone size with bone architecture and BTM, and odds ratio (OR) for fracture. Increasing age, height, and larger total cross-sectional area (TCSA) were associated with larger transitional zone CSA and transitional zone CSA/TCSA (standardized coefficients [STB] = 0.11 to 0.80, p ≤ 0.05). Increasing weight was associated with larger TCSA, but smaller transitional zone CSA/TCSA and thicker cortices (STB = 0.15 to 0.22, p zone (STB = 0.12 to 0.46, p zone CSA/TCSA, and higher porosity of each of the cortical compartments (p zone CSA and higher porosity than controls (p zone, OR for fracture was 1.71 (95% CI, 1.37 to 2.14) and 1.51 (95% CI, 1.23 to 1.85), respectively. Cortical bone architecture is determined mainly by bone size as built during growth and is modified by lifestyle factors throughout life through bone turnover. Fracture cases exhibited larger transitional zone area and porosity, highlighting the importance of cortical bone architecture for fracture propensity. © 2015 American Society for Bone and Mineral Research.

  10. Differentiation of prostate cancer lesions in the Transition Zone by diffusion-weighted MRI

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    Jie Bao

    Full Text Available Objective: To differentiate prostate cancer lesions in transition zone by diffusion-weighted-MRI (DW-MRI. Methods: Data from a total of 63 patients who underwent preoperative DWI (b of 0–1000 s/mm2 were prospectively collected and processed by a monoexponential (DWI model and compared with a biexponential (IVIM model for quantitation of apparent diffusion coefficients (ADCs, perfusion fraction f, diffusivity D and pseudo-diffusivity D*. Histogram analyses were performed by outlining entire-tumor regions of interest (ROIs. These parameters (separately and combined in a logistic regression model were used to differentiate lesions depending on histopathological analysis of Magnetic Resonance/transrectal Ultrasound (MR/TRUS fusion-guided biopsy. The diagnostic ability of differentiate the PCa from BHP in TZ was analyzed by ROC regression. Histogram analysis of quantitative parameters and Gleason score were assessed with Spearman correlation. Results: Thirty (30 foci cases of PCa in PZ and 33 (36 foci cases of BPH were confirmed by pathology. Mean ADC, median ADC, 10th percentile ADC, 90th percentile ADC, kurtosis and skewness of ADC and mean D values, median D and 90th percentile D differed significantly between PCa and BHP in TZ. The highest classification accuracy was achieved by the mean ADC (0.841 and mean D (0.809. A logistic regression model based on mean ADC and mean D led to an AUC of 0.873, however, the difference is not significant. There were 7 Gleason 6 areas, 9 Gleason 7 areas, 8 Gleason 8 areas, 5 Gleason 9 areas and 2 Gleason 10 areas detected from the 31 prostate cancer areas, the mean Gleason value was(7.5 ± 1.2. The mean ADC and mean D had correlation with Gleason score(r = −0.522 and r = −0.407 respectively, P < 0.05. Conclusion: The diagnosis efficiency of IVIM parameters was not superior to ADC in the diagnosis of PCa in TZ. Moreover, the combination of mean ADC and mean D did not

  11. Forging the Link: Using a Conservative Mixing Framework to Characterize Connections between Rivers and Great Lakes in River-lake Transition Zones

    Science.gov (United States)

    River-to-Great Lake transition zones are hydrologically, biogeochemically and biologically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. Our goal is to characterize the biogeochemical properties of the river-lake transition zones and under...

  12. TRANSIT SURVEYS FOR EARTHS IN THE HABITABLE ZONES OF WHITE DWARFS

    International Nuclear Information System (INIS)

    Agol, Eric

    2011-01-01

    To date the search for habitable Earth-like planets has primarily focused on nuclear burning stars. I propose that this search should be expanded to cool white dwarf stars that have expended their nuclear fuel. I define the continuously habitable zone of white dwarfs and show that it extends from ∼0.005 to 0.02 AU for white dwarfs with masses from 0.4 to 0.9 M sun , temperatures less than ∼10 4 K, and habitable durations of at least 3 Gyr. As they are similar in size to Earth, white dwarfs may be deeply eclipsed by terrestrial planets that orbit edge-on, which can easily be detected with ground-based telescopes. If planets can migrate inward or reform near white dwarfs, I show that a global robotic telescope network could carry out a transit survey of nearby white dwarfs placing interesting constraints on the presence of habitable Earths. If planets were detected, I show that the survey would favor detection of planets similar to Earth: similar size, temperature, and rotation period, and host star temperatures similar to the Sun. The Large Synoptic Survey Telescope could place even tighter constraints on the frequency of habitable Earths around white dwarfs. The confirmation and characterization of these planets might be carried out with large ground and space telescopes.

  13. Distribution of Neuroendocrine Cells in the Transition Zone of the Prostate

    Directory of Open Access Journals (Sweden)

    Yuki Kyoda

    2017-01-01

    Full Text Available Objectives. To evaluate the distribution of neuroendocrine (NE cells which may influence the development of benign prostatic hyperplasia (BPH in the transition zone (TZ. Methods. We reviewed specimens from 80 patients who underwent radical prostatectomy in our institution and evaluated the density of NE cells in the TZ. They were histologically classified into 3 groups: those with no adenomatous nodule in the TZ (group A, those with small nodules with normal epithelium and stroma around them in the TZ (group B, and those with large nodules occupying the TZ (group C. In the patients of group B, intra-adenoma (adenomatous nodules and extra-adenoma (normal tissue NE cells in the TZ were separately counted. Results. There were 22, 23, and 35 patients in groups A, B, and C, respectively. The median density of NE cells in the TZ of group B patients, 2.80/mm2, was significantly higher than that of NE cells in group A, 1.43/mm2, and group C, 0.61/mm2 (p<0.001. In group B, the median density of extra-adenoma NE cells was significantly higher than that of intra-adenoma. Conclusions. Many NE cells exist around small adenoma in the TZ. NE cells may influence the initial growth of BPH in a paracrine fashion. Trial Registration. This study approved by our institutional review board was retrospectively registered (#272-14.

  14. Large and giant hydrocarbon accumulations in the transitional continent-ocean zone

    Science.gov (United States)

    Khain, V. E.; Polyakova, I. D.

    2008-05-01

    The petroleum resource potential is considered for the Atlantic, West Pacific, and East Pacific types of deepwater continental margins. The most considerable energy resources are concentrated at the Atlantic-type passive margins in the zone transitional to the ocean. The less studied continental slope of backarc seas of the generally active margins of the West Pacific type is currently not so rich in discoveries as the Atlantic-type margin, but is not devoid of certain expectations. In some of their parameters, the margins bounded by continental slopes may be regarded as analogs of classical passive margins. At the margins of the East Pacific type, the petroleum potential is solely confined to transform segments. In the shelf-continental-slope basins of the rift and pull-apart nature, petroleum fields occur largely in the upper fan complex, and to a lesser extent in the lower graben (rift) complex. In light of world experience, the shelf-continental-slope basins of the Arctic and Pacific margins of Russia are evaluated as highly promising.

  15. Soil Structure Evaluation Across Geologic Transition Zones Using 2D Electrical Resistivity Imaging Technique

    Directory of Open Access Journals (Sweden)

    Geraldine C Anukwu

    2017-06-01

    Full Text Available This study utilizes the electrical resistivity values obtained using 2-D Electrical resistivity imaging (ERI technique to evaluate the subsurface lithology across different geological units. The primary objective was to determine the effect of subsurface lithology on the integrity of a road pavement, which had developed cracks and potholes at various locations. The dipole-dipole configuration was utilized and a total of nine traverses were established in the study area, whose geology cuts across both the basement and sedimentary complexes. The inverted resistivity section obtained showed significant variation in resistivity along established traverses and also across the different rock units, with the resistivity value ranging from about 4 ohm-m to greater than 7000 ohm- m. The lithology as interpreted from the resistivity section revealed the presence topsoil, clay, sandy clay, sand, sand stones/basement rocks, with varying vertical and horizontal arrangements to a depth of 40m. Results suggest that the geologic sequence and structure might have contributed to the observed pavement failure. The capability of the 2D ERI as an imaging tool is observed, especially across the transition zones as depicted in this study. The study further stressed the ability of this technique if properly designed and implemented, to be capable of providing a wealth of information that could complement other traditional geotechnical and geologic techniques.

  16. Role of Transition Zone Index in the Prediction of Clinical Benign Prostatic Hyperplasia

    Directory of Open Access Journals (Sweden)

    Muhammet Güzelsoy

    2016-12-01

    Full Text Available Objective The objective of this study was to determine the role of the transition zone (TZ index (TZI in the prediction of clinical benign prostatic hyperplasia (BPH in patients who underwent transurethral prostatectomy (TUR-P and to analyze the correlation between the amount of resected tissue and TZ volume (TZV. Materials and Methods Twenty-six male clinical BPH patients with obstructive complaints and 17 male benign prostate enlargement (BPE patients without any complaints were included in the study. Both the groups were over the age of 50. Clinical BPH patients underwent complete TUR-P. Statistical analysis was done with SPSS. Sensitivity, specificity, positive and negative predictive values of TZI-as a method of assessing clinical BPH-were measured. Results There was a statistically significant difference in prostate volume, uroflowmetry patterns, prostate-specific antigen (PSA, International prostate symptom score (IPSS, TZV and TZI between the two groups. There was a correlation between TZV and the amount of resected tissue (r=0.97; p0.40 has a high level of sensitivity and specificity in the prediction of clinical BPH among patients who undergo TUR-P due to obstructive symptoms and reported as BPH. There is a strong correlation between the amount of resected tissue and TZV. TZI is a valuable tool in diagnosis, and TZV gives valuable information about the patient to the surgeon.

  17. STEEL-SLAG AS SUBSTITUTE TO NATURAL AGGREGATES, PROPERTIES AND THE INTERFACIAL TRANSITION ZONE

    Directory of Open Access Journals (Sweden)

    Han Ay Lie

    2012-02-01

    Full Text Available Steel-slag is a residual product of the steel industry that has potential ability to pollute the ground water and soil containing heavy metals. To overcome this problem, attempts have been made for using the slag as substitute for both coarse and fine aggregates in concrete. The solidification process will prevent the metal components from polluting the water and soil. Test results on the mechanical properties of slag-concrete showed that while the compression strength of slag-concrete increased significantly as a function of slag-to-natural aggregate’s use, the tensile strength dropped accordingly. The substitution of fine-slag to Muntilan sand was even more negative, the compression strength decreased as a function of slag use. Research into the influences of the Interfacial Transition Zone was conducted, since the ITZ itself forms a weak link within the concrete matrix. The SEM tests were performed at the Quarter Laboratory, Department of Geology in Bandung using a Scanning Electron Microscope type JEOL.

  18. Finite Element Method Analysis of An Out Flow With Free Surface In Transition Zones

    Science.gov (United States)

    Saoula, R. Iddir S.; Mokhtar, K. Ait

    The object of this work is to present this part of the fluid mechanics that relates to out-flows of the fluid to big speeds in transitions. Results usually gotten by the classic processes can only have a qualitative aspect. The method fluently used for the count of these out-flows to big speeds is the one of characteristics, this approach remains interesting so much that doesn't appear within the out-flow of intersections of shock waves, as well as of reflections of these. In the simple geometry case, the method of finite differences satisfying result, But when the complexity of this geometry imposes itself, it is the method of finite elements that is proposed to solve this type of prob- lem, in particular for problems Trans critic. The goal of our work is to analyse free surface flows in channels no prismatic has oblong transverse section in zone of tran- sition. (Convergent, divergent). The basic mathematical model of this study is Saint Venant derivatives partial equations. To solve these equations we use the finite ele- ment method, the element of reference is the triangular element with 6 nodes which are quadratic in speed and linear in height (pressure). Our results and their obtains by others are very close to experimental results.

  19. Investigating the relationship between the mantle transition zone and the fate of subducted slabs: an adaptative-mesh numerical approach

    Science.gov (United States)

    Garel, F.; Davies, R.; Goes, S. D.; Davies, J.; Lithgow-Bertelloni, C. R.; Stixrude, L. P.

    2012-12-01

    Seismic observations show a wide range of slab morphologies within the mantle transition zone. This zone is likely to have been critical in Earth's thermal and chemical evolution, acting as a 'valve' that controls material transfer between the upper and lower mantle. However, the interaction between slabs and this complex region remains poorly understood. The complexity arises from non-linear and multi-scale interactions between several aspects of the mantle system, including mineral phase changes and material rheology. In this study, we will utilize new, multi-scale geodynamic models to determine what controls the seismically observed variability in slab behavior within the mantle transition zone and, hence, the down-going branch of the mantle 'valve'. Our models incorporate the newest mineral physics and theoretical constraints on density, phase proportions and rheology. In addition we exploit novel and unique adaptive grid methodologies to provide the resolution necessary to capture rapid changes in material properties in and around the transition zone. Our early results, which will be presented, illustrate the advantages of the new modelling technique for studying subduction including the effects of changes in material properties and mineral phases.

  20. 2-dimensional triplicated waveform modeling of the mantle transition zone beneath Northeast Asia

    Science.gov (United States)

    Lai, Y.; Chen, L.; Wang, T.

    2017-12-01

    The Mantle Transition Zone (MTZ) of Northeast Asia has long been investigated by geoscientists for its critical importance where the subducted Pacific slab is stagnant above the 660km discontinuity, accompanied by complicated mantle processes. Taking advantages of the frequent occurrent deep earthquakes in subduction zone and dense seismic arrays in Northeast China, we successfully constructed the fine-scale P and SH velocity structure of a narrow azimuthal fan area based on 2-Dimensional (2D) triplicated waveform modeling for three deep close earthquakes, in which the triplicated waveforms are very sensitive to MTZ velocity structure in general, particularly the morphology of the stagnant slab in Northeast Asia. In our 2D triplication study, for the first time, we show a quite consistent feature of a high velocity layer for both Vp and Vs with the thickness of 140km and the length of 1200km just atop the 660km discontinuity, the western edge of the stagnant slab intersect with the North-South Gravity Lineament in China and has the subducting age of 30 Ma. Compared with a quite normal Vp, the Shear wave velocity reduction of -0.5% in the slab and -2.5% in the upper MTZ is required to reconcile the SH waves featured by the broad BOD. The high Vp/Vs ratio beneath Northeast Asia may imply a water-rich MTZ with the H2O content of 0.1-0.3 wt%. Particularly, a low velocity anomaly of about 150km wide was detected in the overall high-velocity stagnant slab by both P and SH triplicated waveform modeling, with the velocity anomaly value of -1% and -3%, respectively. The gap/window in the stagnant slab may provide a passage for hot deeper mantle materials to penetrate through the thick slab and feed the surface Changbaishan volcano. We also speculate that the existence of such a gap can be the manifestation of the original heterogeneity in the subducted slab and will further exacerbatethe impending gravitational instability and speed up mantle avalanche.

  1. Testosterone and dihydrotestosterone levels in the transition zone correlate with prostate volume.

    Science.gov (United States)

    Pejčić, Tomislav; Tosti, Tomislav; Tešić, Živoslav; Milković, Borivoj; Dragičević, Dejan; Kozomara, Milutin; Čekerevac, Milica; Džamić, Zoran

    2017-07-01

    There is still no consensus regarding intraprostatic androgen levels and the accumulation of androgens in the hyperplastic prostatic tissue. The current opinion is that intraprostatic dihydrotestosterone (DHT) concentrations are maintained but not elevated in benign prostatic hyperplasia (BPH), while there is no similar data concerning intraprostatic testosterone (T). Tissue T (tT) and tissue DHT (tDHT) concentration were determined in 93 patients scheduled for initial prostate biopsy. The criteria for biopsy were abnormal DRE and/or PSA > 4 ng/mL. Total prostate volume (TPV) was determined by transrectal ultrasound (TRUS). During TRUS- guided prostate biopsy, 10-12 samples were collected from the peripheral zone (PZ) and two additional samples were collected from the transition zone (TZ). The samples from the TZ were immediately frozen in liquid nitrogen at -70°C, and transported for tissue androgen determination, using liquid chromatography mass spectrometry (LC-MS). Pathological analysis revealed that prostate cancer (PCa) was present in 45 and absent in 48 patients. In the whole group, there were 42 men with small prostate (TPV prostate (TPV ≥ 31 mL). The overall average tT level was 0.79 ± 0.66 ng/g, while the average tDHT level was 10.27 ± 7.15 ng/g. There were no differences in tT and tDHT level in prostates with and without PCa. However, tT and tDHT levels were significantly higher in larger, than in smaller prostates (tT: 1.05 ± 0.75 and 0.46 ± 0.29 ng/g, and tDHT: 15.0 ± 6.09 and 4.51 ± 2.75 ng/g, respectively). There were strong correlations between tT and TPV (r = 0.71), and tDHT and TPV (r = 0.74). The present study confirmed that both T and DHT accumulated in the stroma of enlarged prostates; the degree of accumulation correlated with prostate volume. © 2017 Wiley Periodicals, Inc.

  2. Low incidence of prostate cancer identified in the transition and anterior zones with transperineal biopsy

    Directory of Open Access Journals (Sweden)

    Danforth TL

    2012-12-01

    Full Text Available Teresa L Danforth,1 K Kent Chevli,1,2 Louis Baumann,1,2 Michael Duff1,21The State University of New York (SUNY, Buffalo, NY, 2Cancer Care of Western New York, Cheektowaga, NY, USAPurpose: Determine the incidence of anterior (AZ and transition (TZ zone prostate cancers using a transperineal mapping approach.Methods: A retrospective review of 137 patients with history of previous negative biopsy undergoing transperineal saturation biopsy for an elevated prostate-specific antigen (PSA, high-grade prostate intraepithelial neoplasia, atypical small acinar proliferation history, or abnormal digital rectal exam. The number of biopsy cores was determined by prostate volume and obtained using a predefined template. The electronic medical records were reviewed for patients' clinical and pathological characteristics.Results: Forty-one of 137 patients (31.4% had positive biopsy for prostate adenocarcinoma; 11 were from 24-core, 19 from 36-core, and 11 from 48-core sampling. Glands > 45 mL had a mean of 1.7 previous biopsies and a PSA of 9.1 ng/mL. Glands < 30 mL were 1.3 and 6.3 ng/mL and glands 30–45 mL were 1.4 and 6.5 ng/mL. Glands < 45 mL had a higher number of positive biopsies per total cores. Seven patients chose active surveillance while 34 chose treatment. Of the 36- and 48-cores biopsies, 2.2% and 1.5%, respectively, were positive in the TZ. One patient was AZ-positive, 1 was TZ-positive, and 18 were peripheral zone (PZ-positive alone. Twelve patients had cancer detected in PZ and TZ. Two patients developed urinary retention and one had a urine infection.Conclusion: Transperineal saturation biopsy is a safe and efficacious method of prostate cancer detection in patients with previous negative biopsy and high suspicion for cancer. Few cancers were found to originate in the TZ or AZ alone. We recommend that initial biopsy templates should sample PZ with less focus on the TZ.Keywords: carcinoma, prostate, biopsy, transperineal

  3. Molecular landscape of modified histones in Drosophila heterochromatic genes and euchromatin-heterochromatin transition zones.

    Directory of Open Access Journals (Sweden)

    Jiro C Yasuhara

    2008-01-01

    Full Text Available Constitutive heterochromatin is enriched in repetitive sequences and histone H3-methylated-at-lysine 9. Both components contribute to heterochromatin's ability to silence euchromatic genes. However, heterochromatin also harbors hundreds of expressed genes in organisms such as Drosophila. Recent studies have provided a detailed picture of sequence organization of D. melanogaster heterochromatin, but how histone modifications are associated with heterochromatic sequences at high resolution has not been described. Here, distributions of modified histones in the vicinity of heterochromatic genes of normal embryos and embryos homozygous for a chromosome rearrangement were characterized using chromatin immunoprecipitation and genome tiling arrays. We found that H3-di-methylated-at-lysine 9 (H3K9me2 was depleted at the 5' ends but enriched throughout transcribed regions of heterochromatic genes. The profile was distinct from that of euchromatic genes and suggests that heterochromatic genes are integrated into, rather than insulated from, the H3K9me2-enriched domain. Moreover, the profile was only subtly affected by a Su(var3-9 null mutation, implicating a histone methyltransferase other than SU(VAR3-9 as responsible for most H3K9me2 associated with heterochromatic genes in embryos. On a chromosomal scale, we observed a sharp transition to the H3K9me2 domain, which coincided with increased retrotransposon density in the euchromatin-heterochromatin (eu-het transition zones on the long chromosome arms. Thus, a certain density of retrotransposons, rather than specific boundary elements, may demarcate Drosophila pericentric heterochromatin. We also demonstrate that a chromosome rearrangement that created a new eu-het junction altered H3K9me2 distribution and induced new euchromatic sites of enrichment as far as several megabases away from the breakpoint. Taken together, the findings argue against simple classification of H3K9me as the definitive signature

  4. Differences in microRNA expression during tumor development in the transition and peripheral zones of the prostate

    International Nuclear Information System (INIS)

    Carlsson, Jessica; Helenius, Gisela; Karlsson, Mats G; Andrén, Ove; Klinga-Levan, Karin; Olsson, Björn

    2013-01-01

    The prostate is divided into three glandular zones, the peripheral zone (PZ), the transition zone (TZ), and the central zone. Most prostate tumors arise in the peripheral zone (70-75%) and in the transition zone (20-25%) while only 10% arise in the central zone. The aim of this study was to investigate if differences in miRNA expression could be a possible explanation for the difference in propensity of tumors in the zones of the prostate. Patients with prostate cancer were included in the study if they had a tumor with Gleason grade 3 in the PZ, the TZ, or both (n=16). Normal prostate tissue was collected from men undergoing cystoprostatectomy (n=20). The expression of 667 unique miRNAs was investigated using TaqMan low density arrays for miRNAs. Student’s t-test was used in order to identify differentially expressed miRNAs, followed by hierarchical clustering and principal component analysis (PCA) to study the separation of the tissues. The ADtree algorithm was used to identify markers for classification of tissues and a cross-validation procedure was used to test the generality of the identified miRNA-based classifiers. The t-tests revealed that the major differences in miRNA expression are found between normal and malignant tissues. Hierarchical clustering and PCA based on differentially expressed miRNAs between normal and malignant tissues showed perfect separation between samples, while the corresponding analyses based on differentially expressed miRNAs between the two zones showed several misplaced samples. A classification and cross-validation procedure confirmed these results and several potential miRNA markers were identified. The results of this study indicate that the major differences in the transcription program are those arising during tumor development, rather than during normal tissue development. In addition, tumors arising in the TZ have more unique differentially expressed miRNAs compared to the PZ. The results also indicate that separate mi

  5. Validation of Small Kepler Transiting Planet Candidates in or near the Habitable Zone

    Science.gov (United States)

    Torres, Guillermo; Kane, Stephen R.; Rowe, Jason F.; Batalha, Natalie M.; Henze, Christopher E.; Ciardi, David R.; Barclay, Thomas; Borucki, William J.; Buchhave, Lars A.; Crepp, Justin R.; Everett, Mark E.; Horch, Elliott P.; Howard, Andrew W.; Howell, Steve B.; Isaacson, Howard T.; Jenkins, Jon M.; Latham, David W.; Petigura, Erik A.; Quintana, Elisa V.

    2017-12-01

    A main goal of NASA’s Kepler Mission is to establish the frequency of potentially habitable Earth-size planets ({η }\\oplus ). Relatively few such candidates identified by the mission can be confirmed to be rocky via dynamical measurement of their mass. Here we report an effort to validate 18 of them statistically using the BLENDER technique, by showing that the likelihood they are true planets is far greater than that of a false positive. Our analysis incorporates follow-up observations including high-resolution optical and near-infrared spectroscopy, high-resolution imaging, and information from the analysis of the flux centroids of the Kepler observations themselves. Although many of these candidates have been previously validated by others, the confidence levels reported typically ignore the possibility that the planet may transit a star different from the target along the same line of sight. If that were the case, a planet that appears small enough to be rocky may actually be considerably larger and therefore less interesting from the point of view of habitability. We take this into consideration here and are able to validate 15 of our candidates at a 99.73% (3σ) significance level or higher, and the other three at a slightly lower confidence. We characterize the GKM host stars using available ground-based observations and provide updated parameters for the planets, with sizes between 0.8 and 2.9 R ⊕. Seven of them (KOI-0438.02, 0463.01, 2418.01, 2626.01, 3282.01, 4036.01, and 5856.01) have a better than 50% chance of being smaller than 2 R ⊕ and being in the habitable zone of their host stars.

  6. Ps mantle transition zone imaging beneath the Colorado Rocky Mountains: Evidence for an upwelling hydrous mantle

    Science.gov (United States)

    Zhang, Zhu; Dueker, Kenneth G.; Huang, Hsin-Hua

    2018-06-01

    We analyze teleseismic P-to-S conversions for high-resolution imaging of the mantle transition zone beneath the Colorado Rocky Mountains using data from a dense PASSCAL seismic broadband deployment. A total of 6,021 P-to-S converted receiver functions are constructed using a multi-channel minimum-phase deconvolution method and migrated using the common converted point technique with the 3-D teleseismic P- and S-wave tomography models of Schmandt and Humphreys (2010). The image finds that the average depths of the 410-km discontinuity (the 410) and 660-km discontinuity (the 660) at 408 ± 1.9 km and 649 ± 1.6 km respectively. The peak-to-peak topography of both discontinuities is 33 km and 27 km respectively. Additionally, prominent negative polarity phases are imaged both above and below the 410. To quantify the mean properties of the low-velocity layers about 410 km, we utilize double gradient layer models parameterization to fit the mean receiver function waveform. This waveform fitting is accomplished as a grid-search using anelastic synthetic seismograms. The best-fitting model reveals that the olivine-wadsleyite phase transformation width is 21 km, which is significantly larger than anhydrous mineral physics prediction (4-10 km) (Smyth and Frost, 2002). The findings of a wide olivine-wadsleyite phase transformation and the negative polarity phases above and below the 410, suggest that the mantle, at least in the 350-450 km depth range, is significantly hydrated. Furthermore, a conspicuous negative polarity phase below the 660 is imaged in high velocity region, we speculate the low velocity layer is due to dehydration flux melting in an area of convective downwelling. Our interpretation of these results, in tandem with the tomographic image of a Farallon slab segment at 800 km beneath the region (Schmandt and Humphreys, 2010), is that hydrous and upwelling mantle contributes to the high-standing Colorado Rocky Mountains.

  7. Decomposition of Phragmites australis rhizomes in artificial land-water transitional zones (ALWTZs) and management implications

    Science.gov (United States)

    Han, Zhen; Cui, Baoshan; Zhang, Yongtao

    2015-09-01

    Rhizomes are essential organs for growth and expansion of Phragmites australis. They function as an important source of organic matter and as a nutrient source, especially in the artificial land-water transitional zones (ALWTZs) of shallow lakes. In this study, decomposition experiments on 1- to 6-year-old P. australis rhizomes were conducted in the ALWTZ of Lake Baiyangdian to evaluate the contribution of the rhizomes to organic matter accumulation and nutrient release. Mass loss and changes in nutrient content were measured after 3, 7, 15, 30, 60, 90, 120, and 180 days. The decomposition process was modeled with a composite exponential model. The Pearson correlation analysis was used to analyze the relationships between mass loss and litter quality factors. A multiple stepwise regression model was utilized to determine the dominant factors that affect mass loss. Results showed that the decomposition rates in water were significantly higher than those in soil for 1- to 6-year-old rhizomes. However, the sequence of decomposition rates was identical in both water and soil. Significant relationships between mass loss and litter quality factors were observed at a later stage, and P-related factors proved to have a more significant impact than N-related factors on mass loss. According to multiple stepwise models, the C/P ratio was found to be the dominant factor affecting the mass loss in water, and the C/N and C/P ratios were the main factors affecting the mass loss in soil. The combined effects of harvesting, ditch broadening, and control of water depth should be considered for lake administrators.

  8. Transitions in Land Use Architecture under Multiple Human Driving Forces in a Semi-Arid Zone

    Directory of Open Access Journals (Sweden)

    Issa Ouedraogo

    2015-07-01

    Full Text Available The present study aimed to detect the main shifts in land-use architecture and assess the factors behind the changes in typical tropical semi-arid land in Burkina Faso. Three sets of time-series LANDSAT data over a 23-year period were used to detect land use changes and their underpinning drivers in multifunctional but vulnerable ecologies. Group discussions in selected villages were organized for mapping output interpretation and collection of essential drivers of change as perceived by local populations. Results revealed profound changes and transitions during the study period. During the last decade, shrub and wood savannahs exhibited high net changes (39% and −37% respectively with a weak net positive change for cropland (only 2%, while cropland and shrub savannah exhibited high swap (8% and 16%. This suggests that the area of cropland remained almost unchanged but was subject to relocation, wood savannah decreased drastically, and shrub savannah increased exponentially. Cropland exhibited a null net persistence while shrub and wood savannahs exhibited positive and negative net persistence (1.91 and −10.24, respectively, indicating that there is movement toward agricultural intensification and wood savannah tended to disappear to the benefit of shrub savannah. Local people are aware of the changes that have occurred and support the idea that illegal wood cutting and farming are inappropriate farming practices associated with immigration; absence of alternative cash generation sources, overgrazing and increasing demand for wood energy are driving the changes in their ecosystems. Policies that integrate restoration and conservation of natural ecosystems and promote sustainable agroforestry practices in the study zone are highly recommended.

  9. Logistic regression model for diagnosis of transition zone prostate cancer on multi-parametric MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dikaios, Nikolaos; Halligan, Steve; Taylor, Stuart; Atkinson, David; Punwani, Shonit [University College London, Centre for Medical Imaging, London (United Kingdom); University College London Hospital, Departments of Radiology, London (United Kingdom); Alkalbani, Jokha; Sidhu, Harbir Singh; Fujiwara, Taiki [University College London, Centre for Medical Imaging, London (United Kingdom); Abd-Alazeez, Mohamed; Ahmed, Hashim; Emberton, Mark [University College London, Research Department of Urology, London (United Kingdom); Kirkham, Alex; Allen, Clare [University College London Hospital, Departments of Radiology, London (United Kingdom); Freeman, Alex [University College London Hospital, Department of Histopathology, London (United Kingdom)

    2014-09-17

    We aimed to develop logistic regression (LR) models for classifying prostate cancer within the transition zone on multi-parametric magnetic resonance imaging (mp-MRI). One hundred and fifty-five patients (training cohort, 70 patients; temporal validation cohort, 85 patients) underwent mp-MRI and transperineal-template-prostate-mapping (TPM) biopsy. Positive cores were classified by cancer definitions: (1) any-cancer; (2) definition-1 [≥Gleason 4 + 3 or ≥ 6 mm cancer core length (CCL)] [high risk significant]; and (3) definition-2 (≥Gleason 3 + 4 or ≥ 4 mm CCL) cancer [intermediate-high risk significant]. For each, logistic-regression mp-MRI models were derived from the training cohort and validated internally and with the temporal cohort. Sensitivity/specificity and the area under the receiver operating characteristic (ROC-AUC) curve were calculated. LR model performance was compared to radiologists' performance. Twenty-eight of 70 patients from the training cohort, and 25/85 patients from the temporal validation cohort had significant cancer on TPM. The ROC-AUC of the LR model for classification of cancer was 0.73/0.67 at internal/temporal validation. The radiologist A/B ROC-AUC was 0.65/0.74 (temporal cohort). For patients scored by radiologists as Prostate Imaging Reporting and Data System (Pi-RADS) score 3, sensitivity/specificity of radiologist A 'best guess' and LR model was 0.14/0.54 and 0.71/0.61, respectively; and radiologist B 'best guess' and LR model was 0.40/0.34 and 0.50/0.76, respectively. LR models can improve classification of Pi-RADS score 3 lesions similar to experienced radiologists. (orig.)

  10. The ichthyoplankton assemblage of the Canaries-African Coastal Transition Zone: A review

    Science.gov (United States)

    Rodriguez, J. M.; Moyano, M.; Hernandez-Leon, S.

    2009-12-01

    In this paper we review information on the ichthyoplankton assemblage of the Canaries-African Coastal Transition Zone (C-ACTZ). This CTZ shows the singularity that the Canary Archipelago interrupts the main flow of the Canary Current and Trade Winds, introducing large mesoscale variability, in the form of island warm wakes and cyclonic and anticyclonic eddies downstream of the islands. Besides, upwelling filaments stretch towards the archipelago from the African coastal upwelling, transporting phytoplankton, zooplankton and fish larvae. They also interact with eddies shed from the islands to exchange water properties and biogenic material. All these mesoscale features influence the composition, structure, abundance and distribution of the larval fish community (LFC) of the region. The Canary Current (CC) and eddies shed from the islands drag larvae of island neritic fish species into the oceanic region and contribute, along warm wakes, to the horizontal distribution of fish larvae. Upwelling and upwelling filaments transport larvae of African neritic species into the oceanic region. These larvae dominate the LFC and account for the relatively high average larval fish abundance found in the C-ACTZ during the summer upwelling season. Filaments originated in the region of Cape Juby-Cape Bojador are entrained around a quasi-permanent cyclonic eddy, trapped between Gran Canaria Island and the African coast, forming a system through which most of the African neritic larvae may return to the African shelf. However, some larvae reach the eastern islands of the Canary archipelago and they may be spread all over the neritic region of the archipelago by eddies shed from the islands. Also in summer, the distribution of the LFC of the C-ACTZ is vertically stratified and fish larvae seem to carry out little or not diel vertical migration. Overall, this study highlights the strong relationship between mesoscale oceanographic processes and the LFC in the C-ACTZ.

  11. Logistic regression model for diagnosis of transition zone prostate cancer on multi-parametric MRI

    International Nuclear Information System (INIS)

    Dikaios, Nikolaos; Halligan, Steve; Taylor, Stuart; Atkinson, David; Punwani, Shonit; Alkalbani, Jokha; Sidhu, Harbir Singh; Fujiwara, Taiki; Abd-Alazeez, Mohamed; Ahmed, Hashim; Emberton, Mark; Kirkham, Alex; Allen, Clare; Freeman, Alex

    2015-01-01

    We aimed to develop logistic regression (LR) models for classifying prostate cancer within the transition zone on multi-parametric magnetic resonance imaging (mp-MRI). One hundred and fifty-five patients (training cohort, 70 patients; temporal validation cohort, 85 patients) underwent mp-MRI and transperineal-template-prostate-mapping (TPM) biopsy. Positive cores were classified by cancer definitions: (1) any-cancer; (2) definition-1 [≥Gleason 4 + 3 or ≥ 6 mm cancer core length (CCL)] [high risk significant]; and (3) definition-2 (≥Gleason 3 + 4 or ≥ 4 mm CCL) cancer [intermediate-high risk significant]. For each, logistic-regression mp-MRI models were derived from the training cohort and validated internally and with the temporal cohort. Sensitivity/specificity and the area under the receiver operating characteristic (ROC-AUC) curve were calculated. LR model performance was compared to radiologists' performance. Twenty-eight of 70 patients from the training cohort, and 25/85 patients from the temporal validation cohort had significant cancer on TPM. The ROC-AUC of the LR model for classification of cancer was 0.73/0.67 at internal/temporal validation. The radiologist A/B ROC-AUC was 0.65/0.74 (temporal cohort). For patients scored by radiologists as Prostate Imaging Reporting and Data System (Pi-RADS) score 3, sensitivity/specificity of radiologist A 'best guess' and LR model was 0.14/0.54 and 0.71/0.61, respectively; and radiologist B 'best guess' and LR model was 0.40/0.34 and 0.50/0.76, respectively. LR models can improve classification of Pi-RADS score 3 lesions similar to experienced radiologists. (orig.)

  12. ''Textural analysis of multiparametric MRI detects transition zone prostate cancer''

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, Harbir S.; Johnston, Edward W.; Taylor, Stuart A.; Halligan, Steve [Centre for Medical Imaging, University College London, London (United Kingdom); University College London Hospitals NHS Foundation Trust, London (United Kingdom); Benigno, Salvatore; Dikaios, Nikos [Centre for Medical Imaging, University College London, London (United Kingdom); Ganeshan, Balaji [Institute of Nuclear Medicine, University College London, University College Hospital, London (United Kingdom); Allen, Clare; Kirkham, Alex [University College London Hospitals NHS Foundation Trust, London (United Kingdom); Groves, Ashley M. [University College London Hospitals NHS Foundation Trust, London (United Kingdom); Institute of Nuclear Medicine, University College London, University College Hospital, London (United Kingdom); Ahmed, Hashim U.; Emberton, Mark [University College London Hospitals NHS Foundation Trust, London (United Kingdom); University College London, Research Department of Urology, London (United Kingdom); Punwani, Shonit [Centre for Medical Imaging, University College London, London (United Kingdom); University College London Hospitals NHS Foundation Trust, London (United Kingdom); Centre for Medical Imaging, University College London and University College London Hospitals NIHR Biomedical Research Centre, London (United Kingdom)

    2017-06-15

    To evaluate multiparametric-MRI (mpMRI) derived histogram textural-analysis parameters for detection of transition zone (TZ) prostatic tumour. Sixty-seven consecutive men with suspected prostate cancer underwent 1.5T mpMRI prior to template-mapping-biopsy (TPM). Twenty-six men had 'significant' TZ tumour. Two radiologists in consensus matched TPM to the single axial slice best depicting tumour, or largest TZ diameter for those with benign histology, to define single-slice whole TZ-regions-of-interest (ROIs). Textural-parameter differences between single-slice whole TZ-ROI containing significant tumour versus benign/insignificant tumour were analysed using Mann Whitney U test. Diagnostic accuracy was assessed by receiver operating characteristic area under curve (ROC-AUC) analysis cross-validated with leave-one-out (LOO) analysis. ADC kurtosis was significantly lower (p < 0.001) in TZ containing significant tumour with ROC-AUC 0.80 (LOO-AUC 0.78); the difference became non-significant following exclusion of significant tumour from single-slice whole TZ-ROI (p = 0.23). T1-entropy was significantly lower (p = 0.004) in TZ containing significant tumour with ROC-AUC 0.70 (LOO-AUC 0.66) and was unaffected by excluding significant tumour from TZ-ROI (p = 0.004). Combining these parameters yielded ROC-AUC 0.86 (LOO-AUC 0.83). Textural features of the whole prostate TZ can discriminate significant prostatic cancer through reduced kurtosis of the ADC-histogram where significant tumour is included in TZ-ROI and reduced T1 entropy independent of tumour inclusion. (orig.)

  13. VALIDATION OF 12 SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Guillermo; Kipping, David M.; Fressin, Francois; Newton, Elisabeth R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Caldwell, Douglas A.; Twicken, Joseph D. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ballard, Sarah [University of Washington, Seattle, WA 98195 (United States); Batalha, Natalie M.; Bryson, Stephen T.; Henze, Christopher E.; Howell, Steve B.; Jenkins, Jon M.; Barclay, Thomas; Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Isaacson, Howard T.; Petigura, Erik A. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Muirhead, Philip S. [Department of Astronomy, Boston University, Boston, MA 02215 (United States); Crepp, Justin R. [University of Notre Dame, Notre Dame, IN 46556 (United States); Everett, Mark E., E-mail: gtorres@cfa.harvard.edu [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); and others

    2015-02-20

    We present an investigation of 12 candidate transiting planets from Kepler with orbital periods ranging from 34 to 207 days, selected from initial indications that they are small and potentially in the habitable zone (HZ) of their parent stars. Few of these objects are known. The expected Doppler signals are too small to confirm them by demonstrating that their masses are in the planetary regime. Here we verify their planetary nature by validating them statistically using the BLENDER technique, which simulates large numbers of false positives and compares the resulting light curves with the Kepler photometry. This analysis was supplemented with new follow-up observations (high-resolution optical and near-infrared spectroscopy, adaptive optics imaging, and speckle interferometry), as well as an analysis of the flux centroids. For 11 of them (KOI-0571.05, 1422.04, 1422.05, 2529.02, 3255.01, 3284.01, 4005.01, 4087.01, 4622.01, 4742.01, and 4745.01) we show that the likelihood they are true planets is far greater than that of a false positive, to a confidence level of 99.73% (3σ) or higher. For KOI-4427.01 the confidence level is about 99.2% (2.6σ). With our accurate characterization of the GKM host stars, the derived planetary radii range from 1.1 to 2.7 R {sub ⊕}. All 12 objects are confirmed to be in the HZ, and nine are small enough to be rocky. Excluding three of them that have been previously validated by others, our study doubles the number of known rocky planets in the HZ. KOI-3284.01 (Kepler-438b) and KOI-4742.01 (Kepler-442b) are the planets most similar to the Earth discovered to date when considering their size and incident flux jointly.

  14. Fe-phyllosilicate redox cycling organisms from a redox transition zone in Hanford 300 Area sediments

    Directory of Open Access Journals (Sweden)

    Jason eBenzine

    2013-12-01

    Full Text Available Microorganisms capable of reducing or oxidizing structural iron (Fe in Fe-bearing phyllosilicate minerals were enriched and isolated from a subsurface redox transition zone at the Hanford 300 Area site in eastern Washington, USA. Both conventional and in situ i-chip enrichment strategies were employed. One Fe(III-reducing Geobacter (G. bremensis strain R1, Deltaproteobacteria and six Fe(II phyllosilicate-oxidizing isolates from the Alphaproteobacteria (Bradyrhizobium japonicum strains 22, is5, and in8p8, Betaproteobacteria (Cupriavidus necator strain A5-1, Dechloromonas agitata strain is5, and Actinobacteria (Nocardioides sp. strain in31 were recovered. The G. bremensis isolate grew by oxidizing acetate with the oxidized form of NAu-2 smectite as the electron acceptor. The Fe(II-oxidizers grew by oxidation of chemically reduced smectite as the energy source with nitrate as the electron acceptor. The Bradyrhizobium isolates could also carry out aerobic oxidation of biotite. This is the first report of the recovery of a Fe(II-oxidizing Nocardioides, and to date only one other Fe(II-oxidizing Bradyrhizobium is known. The 16S rRNA gene sequences of the isolates were similar to ones found in clone libraries from Hanford 300 sediments and groundwater, suggesting that such organisms may be present and active in situ. Whole genome sequencing of the isolates is underway, the results of which will enable comparative genomic analysis of mechanisms of extracellular phyllosilicate Fe redox metabolism, and facilitate development of techniques to detect the presence and expression of genes associated with microbial phyllosilicate Fe redox cycling in sediments.

  15. Sulfide enrichment at an oceanic crust-mantle transition zone: Kane Megamullion (23°N, MAR)

    Science.gov (United States)

    Ciazela, Jakub; Koepke, Juergen; Dick, Henry J. B.; Botcharnikov, Roman; Muszynski, Andrzej; Lazarov, Marina; Schuth, Stephan; Pieterek, Bartosz; Kuhn, Thomas

    2018-06-01

    The Kane Megamullion oceanic core complex located along the Mid-Atlantic Ridge (23°30‧N, 45°20‧W) exposes lower crust and upper mantle directly on the ocean floor. We studied chalcophile elements and sulfides in the ultramafic and mafic rocks of the crust-mantle transition and the mantle underneath. We determined mineralogical and elemental composition and the Cu isotope composition of the respective sulfides along with the mineralogical and elemental composition of the respective serpentines. The rocks of the crust-mantle transition zone (i.e., plagioclase harzburgite, peridotite-gabbro contacts, and dunite) overlaid by troctolites are by one order of magnitude enriched in several chalcophile elements with respect to the spinel harzburgites of the mantle beneath. Whereas the range of Cu concentrations in spinel harzburgites is 7-69 ppm, the Cu concentrations are highly elevated in plagioclase harzburgites with a range of 90-209 ppm. The zones of the peridotite-gabbro contacts are even more enriched, exhibiting up to 305 ppm Cu and highly elevated concentrations of As, Zn, Ga, Sb and Tl. High Cu concentrations show pronounced correlation with bulk S concentrations at the crust-mantle transition zone implying an enrichment process in this horizon of the oceanic lithosphere. We interpret this enrichment as related to melt-mantle reaction, which is extensive in crust-mantle transition zones. In spite of the ubiquitous serpentinization of primary rocks, we found magmatic chalcopyrites [CuFeS2] as inclusions in plagioclase as well as associated with pentlandite [(Fe,Ni)9S8] and pyrrhotite [Fe1-xS] in polysulfide grains. These chalcopyrites show a primary magmatic δ65Cu signature ranging from -0.04 to +0.29 ‰. Other chalcopyrites have been dissolved during serpentinization. Due to the low temperature (enrichment, increased sulfide modes, and potentially formation of small sulfide deposits could be expected globally along the petrological Moho.

  16. Modelling of interfacial transition zone effect on resistance to crack propagation in fine-grained cement-based composites

    Czech Academy of Sciences Publication Activity Database

    Šimonová, H.; Vyhlídal, M.; Kucharczyková, B.; Bayer, P.; Keršner, Z.; Malíková, Lucie; Klusák, Jan

    2017-01-01

    Roč. 11, č. 41 (2017), s. 211-219 ISSN 1971-8993 R&D Projects: GA ČR(CZ) GA16-18702S Institutional support: RVO:68081723 Keywords : Effective fracture toughness * Fine-grained concrete * Interfacial transition zone * Three-point bending fracture test * Scanning electron microscopy Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis

  17. Observation of the Spectrally Invariant Properties of Clouds in Cloudy-to-Clear Transition Zones During the MAGIC Field Campaign

    Science.gov (United States)

    Yang, Weidong; Marshak, Alexander; McBride, Patrick; Chiu, J. Christine; Knyazikhin, Yuri; Schmidt, K. Sebastian; Flynn, Connor; Lewis, Ernie R.; Eloranta, Edwin W.

    2016-01-01

    We use the spectrally invariant method to study the variability of cloud optical thickness tau and droplet effective radius r(sub eff) in transition zones (between the cloudy and clear sky columns) observed from Solar Spectral Flux Radiometer (SSFR) and Shortwave Array Spectroradiometer-Zenith (SASZe) during the Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign. The measurements from the SSFR and the SASZe are different, however inter-instrument differences of self-normalized measurements (divided by their own spectra at a fixed time) are small. The spectrally invariant method approximates the spectra in the cloud transition zone as a linear combination of definitely clear and cloudy spectra, where the coefficients, slope and intercept, characterize the spectrally invariant properties of the transition zone. Simulation results from the SBDART (Santa Barbara DISORT Atmospheric Radiative Transfer) model demonstrate that (1) the slope of the visible band is positively correlated with the cloud optical thickness t while the intercept of the near-infrared band has high negative correlation with the cloud drop effective radius r(sub eff)even without the exact knowledge of tau; (2) the above relations hold for all Solar Zenith Angle (SZA) and for cloud-contaminated skies. In observations using redundant measurements from SSFR and SASZe, we find that during cloudy-to-clear transitions, (a) the slopes of the visible band decrease, and (b) the intercepts of the near-infrared band remain almost constant near cloud edges. The findings in simulations and observations suggest that, while the optical thickness decreases during the cloudy-to-clear transition, the cloud drop effective radius does not change when cloud edges are approached. These results support the hypothesis that inhomogeneous mixing dominates near cloud edges in the studied cases.

  18. Three dimensional proton MR spectroscopic imaging in transition zone prostate cancer

    International Nuclear Information System (INIS)

    Yang Yi; Zhao Wenlu; Shen Junkang

    2012-01-01

    Objective: To discuss the clinical value of three dimensional proton MR spectroscopic imaging (3D 1 HMRSI) in the detection of transition zone (TZ) prorate cancer and evaluate the feasibility of 3D 1 HMRSI for determining the aggressiveness of TZ cancer by analyzing its metabolic characteristics. Methods: The 3D 1 HMRSI data of sixty patients suspected TZ cancer in conventional MR examinations were retrospectively analyzed. The values of (Cho + Cre)/Cit of TZ cancer and benign prostatic hyperplasia (BPH) voxels were recorded and compared using independent sample t' test, and the area under the ROC curve was used to evaluate the diagnostic accuracy. Based on Gleason scores, TZ cancer voxels were divided into three groups,including low-risk (Gleason score <7), intermediate-risk (Gleason score =7) and high-risk (Gleason score >7). The values of (Cho + Cre)/Cit were compared among the three groups using Kruskal-Wallis test. The correlation of the value of (Cho + Cre)/Cit and Gleason score was analyzed using rank correlation analysis. Results: Among the 60 patients, histopathology confirmed TZ cancer in 25 patients and BPH in 35 patients. The inversion of Cho and Cit peak value with increased (Cho + Cre)/Cit was detected in 160 out of 177 TZ cancer voxels. Most spectral curves of the 517 BPH voxels were similar with that of normal peripheral zone on 1 HMRSI. The mean values of (Cho + Cre)/Cit of TZ cancer and BPH voxels were 2.17 ± 1.29 and 0.77 ± 0.20, respectively, with significant difference between them (t'=14.38, P<0.01). Using (Cho + Cre)/Cit for distinguishing TZ cancer, the area under ROC curve was 0.985 (P<0.01).With the cut-off point 1.08, the sensitivity, specificity and accuracy of TZ cancer diagnosis was 92.7%, 94.2% and 93.8%, respectively. The number of low-risk, intermediate-risk and high-risk TZ cancer voxels were 57, 64 and 56 respectively, and the mean values of (Cho + Cre)/Cit of the three groups were 1.43 (1.16-1.87), 1.66 (1

  19. Global shear speed structure of the upper mantle and transition zone

    Science.gov (United States)

    Schaeffer, A. J.; Lebedev, S.

    2013-07-01

    resolution of the imaging. Our new shear speed model is parametrized on a triangular grid with a ˜280 km spacing. In well-sampled continental domains, lateral resolution approaches or exceeds that of regional-scale studies. The close match of known surface expressions of deep structure with the distribution of anomalies in the model provides a useful benchmark. In oceanic regions, spreading ridges are very well resolved, with narrow anomalies in the shallow mantle closely confined near the ridge axis, and those deeper, down to 100-120 km, showing variability in their width and location with respect to the ridge. Major subduction zones worldwide are well captured, extending from shallow depths down to the transition zone. The large size of our waveform fit data set also provides a strong statistical foundation to re-examine the validity field of the JWKB approximation and surface wave ray theory. Our analysis shows that the approximations are likely to be valid within certain time-frequency portions of most seismograms with high signal-to-noise ratios, and these portions can be identified using a set of consistent criteria that we apply in the course of waveform fitting.

  20. Environmental Risk of Metal Mining Contaminated River Bank Sediment at Redox-Transitional Zones

    Directory of Open Access Journals (Sweden)

    Sarah F. L. Lynch

    2014-01-01

    Full Text Available Diffuse metal pollution from mining impacted sediment is widely recognised as a potential source of contamination to river systems and may significantly hinder the achievement of European Union Water Framework Directive objectives. Redox-transitional zones that form along metal contaminated river banks as a result of flood and drought cycles could cause biogeochemical changes that alter the behaviour of polyvalent metals iron and manganese and anions such as sulphur. Trace metals are often partitioned with iron, manganese and sulphur minerals in mining-contaminated sediment, therefore the dissolution and precipitation of these minerals may influence the mobility of potentially toxic trace metals. Research indicates that freshly precipitated metal oxides and sulphides may be more “reactive” (more adsorbent and prone to dissolution when conditions change than older crystalline forms. Fluctuations at the oxic-anoxic interface brought about through changes in the frequency and duration of flood and drought episodes may therefore influence the reactivity of secondary minerals that form in the sediment and the flux of dissolved trace metal release. UK climate change models predict longer dry periods for some regions, interspersed with higher magnitude flood events. If we are to fully comprehend the future environmental risk these climate change events pose to mining impacted river systems it is recommended that research efforts focus on identifying the primary controls on trace metal release at the oxic-anoxic interface for flood and drought cycles of different duration and frequency. This paper critically reviews the literature regarding biogeochemical processes that occur at different temporal scales during oxic, reducing and dry periods and focuses on how iron and sulphur based minerals may alter in form and reactivity and influence the mobility of trace metal contaminants. It is clear that changes in redox potential can alter the composition

  1. Logistic regression model for diagnosis of transition zone prostate cancer on multi-parametric MRI.

    Science.gov (United States)

    Dikaios, Nikolaos; Alkalbani, Jokha; Sidhu, Harbir Singh; Fujiwara, Taiki; Abd-Alazeez, Mohamed; Kirkham, Alex; Allen, Clare; Ahmed, Hashim; Emberton, Mark; Freeman, Alex; Halligan, Steve; Taylor, Stuart; Atkinson, David; Punwani, Shonit

    2015-02-01

    We aimed to develop logistic regression (LR) models for classifying prostate cancer within the transition zone on multi-parametric magnetic resonance imaging (mp-MRI). One hundred and fifty-five patients (training cohort, 70 patients; temporal validation cohort, 85 patients) underwent mp-MRI and transperineal-template-prostate-mapping (TPM) biopsy. Positive cores were classified by cancer definitions: (1) any-cancer; (2) definition-1 [≥Gleason 4 + 3 or ≥ 6 mm cancer core length (CCL)] [high risk significant]; and (3) definition-2 (≥Gleason 3 + 4 or ≥ 4 mm CCL) cancer [intermediate-high risk significant]. For each, logistic-regression mp-MRI models were derived from the training cohort and validated internally and with the temporal cohort. Sensitivity/specificity and the area under the receiver operating characteristic (ROC-AUC) curve were calculated. LR model performance was compared to radiologists' performance. Twenty-eight of 70 patients from the training cohort, and 25/85 patients from the temporal validation cohort had significant cancer on TPM. The ROC-AUC of the LR model for classification of cancer was 0.73/0.67 at internal/temporal validation. The radiologist A/B ROC-AUC was 0.65/0.74 (temporal cohort). For patients scored by radiologists as Prostate Imaging Reporting and Data System (Pi-RADS) score 3, sensitivity/specificity of radiologist A 'best guess' and LR model was 0.14/0.54 and 0.71/0.61, respectively; and radiologist B 'best guess' and LR model was 0.40/0.34 and 0.50/0.76, respectively. LR models can improve classification of Pi-RADS score 3 lesions similar to experienced radiologists. • MRI helps find prostate cancer in the anterior of the gland • Logistic regression models based on mp-MRI can classify prostate cancer • Computers can help confirm cancer in areas doctors are uncertain about.

  2. Actin Cytoskeleton-Based Plant Synapse as Gravitransducer in the Transition Zone of the Root Apex

    Science.gov (United States)

    Baluska, Frantisek; Barlow, Peter; Volkmann, Dieter; Mancuso, Stefano

    The actin cytoskeleton was originally proposed to act as the signal transducer in the plant gravity sensory-motoric circuit. Surprisingly, however, several studies have documented that roots perfom gravisensing and gravitropism more effectively if exposed to diverse anti-F-actin drugs. Our study, using decapped maize root apices, has revealed that depolymerization of F-actin stimulates gravity perception in cells of the transition zone where root gravitropism is initiated (Mancuso et al. 2006). It has been proposed (Balǔka et al. 2005, 2009a) that s the non-growing adhesive end-poles, enriched with F-actin and myosin VIII, and active in endocytic recycling of both PIN transporters and cell wall pectins cross-linked with calcium and boron, act as the gravisensing domains, and that these impinge directly upon the root motoric responses via control of polar auxin transport. This model suggests that mechanical asymmetry at these plant synapses determines vectorial gravity-controlled auxin transport. Due to the gravity-imposed mechanical load upon the protoplast, a tensional stress is also imposed upon the plasma membrane of the physically lower synaptic cell pole. This stress is then relieved by shifting the endocytosis-exocytosis balance towards exocytosis (Balǔka et al. s 2005, 2009a,b). This `Synaptic Auxin Secretion' hypothesis does not conflict with the `Starch Statolith' hypothesis, which is based on amyloplast sedimentation. In fact, the `Synaptic Auxin Secretion' hypothesis has many elements which allow its unification with the Starch-Statolith model (Balǔka et al. 2005, 2009a,b). s References Balǔka F, Volkmann D, Menzel D (2005) Plant synapses: actin-based adhesion s domains for cell-to-cell communication. Trends Plant Sci 10: 106-111 Balǔka F, Schlicht M, s Wan Y-L, Burbach C, Volkmann D (2009a) Intracellular domains and polarity in root apices: from synaptic domains to plant neurobiology. Nova Acta Leopoldina 96: 103-122 Balǔka s F, Mancuso S

  3. Novel Pelagic Iron-Oxidizing Zetaproteobacteria from the Chesapeake Bay Oxic–Anoxic Transition Zone

    Science.gov (United States)

    Chiu, Beverly K.; Kato, Shingo; McAllister, Sean M.; Field, Erin K.; Chan, Clara S.

    2017-01-01

    Chemolithotrophic iron-oxidizing bacteria (FeOB) could theoretically inhabit any environment where Fe(II) and O2 (or nitrate) coexist. Until recently, marine Fe-oxidizing Zetaproteobacteria had primarily been observed in benthic and subsurface settings, but not redox-stratified water columns. This may be due to the challenges that a pelagic lifestyle would pose for Zetaproteobacteria, given low Fe(II) concentrations in modern marine waters and the possibility that Fe oxyhydroxide biominerals could cause cells to sink. However, we recently cultivated Zetaproteobacteria from the Chesapeake Bay oxic–anoxic transition zone, suggesting that they can survive and contribute to biogeochemical cycling in a stratified estuary. Here we describe the isolation, characterization, and genomes of two new species, Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8, which are the first Zetaproteobacteria isolates from a pelagic environment. We looked for adaptations enabling strains CP-5 and CP-8 to overcome the challenges of living in a low Fe redoxcline with frequent O2 fluctuations due to tidal mixing. We found that the CP strains produce distinctive dreadlock-like Fe oxyhydroxide structures that are easily shed, which would help cells maintain suspension in the water column. These oxides are by-products of Fe(II) oxidation, likely catalyzed by the putative Fe(II) oxidase encoded by the cyc2 gene, present in both CP-5 and CP-8 genomes; the consistent presence of cyc2 in all microaerophilic FeOB and other FeOB genomes supports its putative role in Fe(II) oxidation. The CP strains also have two gene clusters associated with biofilm formation (Wsp system and the Widespread Colonization Island) that are absent or rare in other Zetaproteobacteria. We propose that biofilm formation enables the CP strains to attach to FeS particles and form flocs, an advantageous strategy for scavenging Fe(II) and developing low [O2] microenvironments within more oxygenated waters

  4. Tracing the Paleo sulfate-methane transition zones and H2S seepage events in marine sediments: An application of C-S-Mo systematics

    Digital Repository Service at National Institute of Oceanography (India)

    Peketi, A; Mazumdar, A; Joshi, R.K.; Patil, D.J.; Srinivas, P.L.; Dayal, A

    Microbially mediated anaerobic oxidation of methane (AOM) coupled with sulfate consumption within the sulfate methane transition zone (SMTZ) in marine sediments is a widely recorded biogeochemical reaction and has profound influence...

  5. Effect of In-Vehicle Audio Warning System on Driver’s Speed Control Performance in Transition Zones from Rural Areas to Urban Areas

    Directory of Open Access Journals (Sweden)

    Xuedong Yan

    2016-06-01

    Full Text Available Speeding is a major contributing factor to traffic crashes and frequently happens in areas where there is a mutation in speed limits, such as the transition zones that connect urban areas from rural areas. The purpose of this study is to investigate the effects of an in-vehicle audio warning system and lit speed limit sign on preventing drivers’ speeding behavior in transition zones. A high-fidelity driving simulator was used to establish a roadway network with the transition zone. A total of 41 participants were recruited for this experiment, and the driving speed performance data were collected from the simulator. The experimental results display that the implementation of the audio warning system could significantly reduce drivers’ operating speed before they entered the urban area, while the lit speed limit sign had a minimal effect on improving the drivers’ speed control performance. Without consideration of different types of speed limit signs, it is found that male drivers generally had a higher operating speed both upstream and in the transition zones and have a larger maximum deceleration for speed reduction than female drivers. Moreover, the drivers who had medium-level driving experience had the higher operating speed and were more likely to have speeding behaviors in the transition zones than those who had low-level and high-level driving experience in the transition zones.

  6. Transition to University Life: Insights from High School and University Female Students in Wolaita Zone, Ethiopia

    Science.gov (United States)

    Thuo, Mary; Edda, Medhanit

    2017-01-01

    The purpose of this study was to get an insight about how high school female students perceive the transition to university life, and to understand the transition experience of university female students in the first semester. An exploratory study design was used where 166 high school female students and 88 first year university female students…

  7. Genetic diversity and biogeographical patterns of Caulerpa prolifera across the Mediterranean and Mediterranean/Atlantic transition zone

    KAUST Repository

    Varela-Á lvarez, Elena; Balau, Ana C.; Marbà , Nú rià N.; Afonso-Carrillo, Julio; Duarte, Carlos M.; Serrã o, Ester Á lvares

    2015-01-01

    Knowledge of spatial patterns of genetic differentiation between populations is key to understanding processes in evolutionary history of biological species. Caulerpa is a genus of marine green algae, which has attracted much public attention, mainly because of the impacts of invasive species in the Mediterranean. However, very little is known about the ecological and evolutionary history of the Mediterranean native Caulerpa prolifera, a species which is currently found at sites distributed worldwide. C. prolifera provides a good model to explore the patterns of genetic diversity at different scales across the Mediterranean and Atlantic area. This study aims to investigate the biogeographical patterns of diversity and differentiation of C. prolifera in the Mediterranean, with special focus on the Mediterranean/Atlantic transition zone. We used two nuclear (ITS rDNA and the hypervariable microsatellite locus CaPr_J2) and one chloroplast (tufA) DNA markers on samples of C. prolifera from its entire range. Analyses of 51 sequences of the cpDNA tufA of C. prolifera, 87 ITS2 sequences and genotypes of 788 ramets of C. prolifera for the locus CaPr_J2 revealed three different biogeographical areas: West Atlantic, East Atlantic and a larger area representing the Mediterranean, the Mediterranean/Atlantic transition zone and a Pacific site (Bali). It was found out that the Mediterranean/Atlantic transition zone is a biogeographical boundary for C. prolifera. A lack of connectivity was revealed between Atlantic and Mediterranean types, and identical sequences found in the Mediterranean and Indo-Pacific suggest either recent gene flow along the Red Sea connection or a possible ancient Indo-Pacific origin.

  8. Genetic diversity and biogeographical patterns of Caulerpa prolifera across the Mediterranean and Mediterranean/Atlantic transition zone

    KAUST Repository

    Varela-Álvarez, Elena

    2015-01-11

    Knowledge of spatial patterns of genetic differentiation between populations is key to understanding processes in evolutionary history of biological species. Caulerpa is a genus of marine green algae, which has attracted much public attention, mainly because of the impacts of invasive species in the Mediterranean. However, very little is known about the ecological and evolutionary history of the Mediterranean native Caulerpa prolifera, a species which is currently found at sites distributed worldwide. C. prolifera provides a good model to explore the patterns of genetic diversity at different scales across the Mediterranean and Atlantic area. This study aims to investigate the biogeographical patterns of diversity and differentiation of C. prolifera in the Mediterranean, with special focus on the Mediterranean/Atlantic transition zone. We used two nuclear (ITS rDNA and the hypervariable microsatellite locus CaPr_J2) and one chloroplast (tufA) DNA markers on samples of C. prolifera from its entire range. Analyses of 51 sequences of the cpDNA tufA of C. prolifera, 87 ITS2 sequences and genotypes of 788 ramets of C. prolifera for the locus CaPr_J2 revealed three different biogeographical areas: West Atlantic, East Atlantic and a larger area representing the Mediterranean, the Mediterranean/Atlantic transition zone and a Pacific site (Bali). It was found out that the Mediterranean/Atlantic transition zone is a biogeographical boundary for C. prolifera. A lack of connectivity was revealed between Atlantic and Mediterranean types, and identical sequences found in the Mediterranean and Indo-Pacific suggest either recent gene flow along the Red Sea connection or a possible ancient Indo-Pacific origin.

  9. Mapping and quantifying geodiversity in land-water transition zones using MBES and topobathymetric LiDAR

    Science.gov (United States)

    Brandbyge Ernstsen, Verner; Skovgaard Andersen, Mikkel; Gergely, Aron; Schulze Tenberge, Yvonne; Al-Hamdani, Zyad; Steinbacher, Frank; Rolighed Larsen, Laurids; Winter, Christian; Bartholomä, Alexander

    2016-04-01

    Land-water transition zones, like e.g. coastal and fluvial environments, are valuable ecosystems which are often characterised by high biodiversity and geodiversity. However, often these land-water transition zones are difficult or even impossible to map and investigate in high spatial resolution due to the challenging environmental conditions. Combining vessel borne shallow water multibeam echosounder (MBES) surveys ,to cover the subtidal coastal areas and the river channel areas, with airborne topobathymetric light detection and ranging (LiDAR) surveys, to cover the intertidal and supratidal coastal areas and the river floodplain areas, potentially enables full-coverage and high-resolution mapping in these challenging environments. We have carried out MBES and topobathymetric LiDAR surveys in the Knudedyb tidal inlet system, a coastal environment in the Danish Wadden Sea which is part of the Wadden Sea National Park and UNESCO World Heritage, and in the Ribe Vesterå, a fluvial environment in the Ribe Å river catchment discharging into the Knudedyb tidal basin. Detailed digital elevation models (DEMs) with a grid cell size of 0.5 m x 0.5 m were generated from the MBES and the LiDAR point clouds, which both have point densities in the order of 20 points/m2. Morphometric analyses of the DEMs enabled the identification and mapping of the different landforms within the coastal and fluvial environments. Hereby, we demonstrate that vessel borne MBES and airborne topobathymetric LiDAR, here in combination, are promising tools for seamless mapping across land-water transition zones as well as for the quantification of a range of landforms at landscape scale in different land-water transition zone environments. Hence, we demonstrate the potential for mapping and quantifying geomorphological diversity, which is one of the main components of geodiversity and a prerequisite for assessing geoheritage. Acknowledgements This work was funded by the Danish Council for

  10. Patterns of forest composition and their long term environmental drivers in the tropical dry forest transition zone of southern Africa

    Directory of Open Access Journals (Sweden)

    Vera De Cauwer

    2016-09-01

    Full Text Available Background Tropical dry forests cover less than 13 % of the world’s tropical forests and their area and biodiversity are declining. In southern Africa, the major threat is increasing population pressure, while drought caused by climate change is a potential threat in the drier transition zones to shrub land. Monitoring climate change impacts in these transition zones is difficult as there is inadequate information on forest composition to allow disentanglement from other environmental drivers. Methods This study combined historical and modern forest inventories covering an area of 21,000 km2 in a transition zone in Namibia and Angola to distinguish late succession tree communities, to understand their dependence on site factors, and to detect trends in the forest composition over the last 40 years. Results The woodlands were dominated by six tree species that represented 84 % of the total basal area and can be referred to as Baikiaea - Pterocarpus woodlands. A boosted regression tree analysis revealed that late succession tree communities are primarily determined by climate and topography. The Schinziophyton rautanenii and Baikiaea plurijuga communities are common on slightly inclined dune or valley slopes and had the highest basal area (5.5 – 6.2 m2 ha−1. The Burkea africana - Guibourtia coleosperma and Pterocarpus angolensis – Dialium englerianum communities are typical for the sandy plateaux and have a higher proportion of smaller stems caused by a higher fire frequency. A decrease in overall basal area or a trend of increasing domination by the more drought and cold resilient B. africana community was not confirmed by the historical data, but there were significant decreases in basal area for Ochna pulchra and the valuable fruit tree D. englerianum. Conclusions The slope communities are more sheltered from fire, frost and drought but are more susceptible to human expansion. The community with the important timber tree P

  11. Data set: A modeling dataset that spans the rain - snow transition zone: Johnston Draw catchment, Reynolds Creek Experimental Watershed, Idaho, USA

    Science.gov (United States)

    Hydrometeorological data from the rain-to-snow transition zone in mountain basins are limited. As the climate warms, the transition from rain to snow in mountain regions is moving to higher elevations, and these changes are altering the timing of water delivery to the downstream streams, lakes and w...

  12. Petrology and geochemistry at the Lower zone-Middle zone transition of the Panzhihua intrusion, SW China: Implications for differentiation and oxide ore genesis

    Directory of Open Access Journals (Sweden)

    Kwan-Nang Pang

    2013-09-01

    Full Text Available A sequence of gabbros showing isotropic, layered and fine-grained textures is exposed in the Nalaqing mine at the southern tip of the ∼260 Ma Panzhihua intrusion, SW China. The field relations, structure, texture and mineralogy of the rocks indicate that the sequence represents the transition between the Lower zone and Middle zone of the intrusion. Isotropic gabbros characteristic of the Lower zone pass upward to layered gabbros of the Middle zone through a ∼5 m-thick microgabbro sheet, within and close to which small-scaled, concordant Fe-Ti oxide ore horizons are identified. Strong fractionation between HFSE and REE in a subset of samples is ascribed to cumulus titanomagnetite into which HFSE are preferentially incorporated over REE, as reflected in the parallel relations between Nb/La, Hf/Sm and Ti/Ti*. Both the isotropic and layered gabbros display cumulate textures and have similar mineral compositions (Mg# of clinopyroxene = ∼76–79 and An59–61, isotopic compositions [(87Sr/86Sri = 0.7044–0.7045 and εNd(t = +2.4 to +3.9] and trapped liquid contents inferred from Zr abundance (∼17–34 ppm. However, there are substantial variations in elemental abundances (V, Cr and PGE and ratios (Ti/V, La/Yb, Ba/Y and Cu/Pd between the two types of gabbros, features that cannot be explained by cumulate formation from a common magma in a closed system. The microgabbros generally resemble high-Ti Emeishan basalts in major element compositions, but their low trace element abundances indicate some lost of residual liquid is inevitable despite rapid nucleation and cooling. Combined with available data and observations, we propose a model involving in-situ crystallization, followed by magma recharge and closed-system fractionation to explain the formation of texturally distinctive gabbros at Nalaqing and the evolution of the lower part of the Panzhihua intrusion.

  13. Heterogeneous seismic anisotropy in the transition zone and uppermost lower mantle: evidence from South America, Izu-Bonin and Japan

    Science.gov (United States)

    Lynner, Colton; Long, Maureen D.

    2015-06-01

    Measurements of seismic anisotropy are commonly used to constrain deformation in the upper mantle. Observations of anisotropy at mid-mantle depths are, however, relatively sparse. In this study we probe the anisotropic structure of the mid-mantle (transition zone and uppermost lower mantle) beneath the Japan, Izu-Bonin, and South America subduction systems. We present source-side shear wave splitting measurements for direct teleseismic S phases from earthquakes deeper than 300 km that have been corrected for the effects of upper mantle anisotropy beneath the receiver. In each region, we observe consistent splitting with delay times as large as 1 s, indicating the presence of anisotropy at mid-mantle depths. Clear splitting of phases originating from depths as great as ˜600 km argues for a contribution from anisotropy in the uppermost lower mantle as well as the transition zone. Beneath Japan, fast splitting directions are perpendicular or oblique to the slab strike and do not appear to depend on the propagation direction of the waves. Beneath South America and Izu-Bonin, splitting directions vary from trench-parallel to trench-perpendicular and have an azimuthal dependence, indicating lateral heterogeneity. Our results provide evidence for the presence of laterally variable anisotropy and are indicative of variable deformation and dynamics at mid-mantle depths in the vicinity of subducting slabs.

  14. A discrete transition zone organizes the topological and regulatory autonomy of the adjacent tfap2c and bmp7 genes.

    Directory of Open Access Journals (Sweden)

    Taro Tsujimura

    2015-01-01

    Full Text Available Despite the well-documented role of remote enhancers in controlling developmental gene expression, the mechanisms that allocate enhancers to genes are poorly characterized. Here, we investigate the cis-regulatory organization of the locus containing the Tfap2c and Bmp7 genes in vivo, using a series of engineered chromosomal rearrangements. While these genes lie adjacent to one another, we demonstrate that they are independently regulated by distinct sets of enhancers, which in turn define non-overlapping regulatory domains. Chromosome conformation capture experiments reveal a corresponding partition of the locus in two distinct structural entities, demarcated by a discrete transition zone. The impact of engineered chromosomal rearrangements on the topology of the locus and the resultant gene expression changes indicate that this transition zone functionally organizes the structural partition of the locus, thereby defining enhancer-target gene allocation. This partition is, however, not absolute: we show that it allows competing interactions across it that may be non-productive for the competing gene, but modulate expression of the competed one. Altogether, these data highlight the prime role of the topological organization of the genome in long-distance regulation of gene expression.

  15. OSO-8 observations of the impulsive phase of solar flares in the transition-zone and corona

    International Nuclear Information System (INIS)

    Lites, B.W.

    1981-01-01

    Several solar flares have been observed from their onset in C IV lambda 1548.2 and 1-8 Angstroem X-rays using instruments aboard OSO-8. In addition, microwave and Hα flare patrol data have been obtained for this study. The impulsive brightening in C IV is frequently accompanied by redshifts, interpreted as downflows, of the order of 80 km s -1 . The maximum soft X-ray intensity usually arrives several minutes after the maximum C IV intensity. The most energetic C IV event studied shows a small blueshift just before reaching maximum intensity, and estimates of the mass flux associated with this upflow through the transition-zone are consistent with the increase of mass in the coronal loops as observed in soft X-rays. This event had no observable microwave burst, suggesting that electron beams did not play a major role in the chromospheric and transition-zone excitation. Lastly, our observations suggest that the frequent occurrence of violent dynamical processes at the onset of the flare are associated with the initial energy release mechanism. (orig.)

  16. Effect of the roughening transition on the vicinal surface in the step droplet zone

    Science.gov (United States)

    Akutsu, Noriko

    2017-06-01

    For vicinal surfaces around the (001) surface inclined towards the 〈 111 〉 direction, the influence of roughening transitions on the surface tension and on step droplets is studied numerically. The surface tension is calculated using a restricted solid-on-solid model with a point-contact type step-step attraction (p-RSOS model) on a square lattice. To ensure the reliability of the calculations, the density matrix renormalization group method is used. The growth rate of the vicinal surface near equilibrium is also calculated by the Monte Carlo method. It is found that the roughening transition changes the morphology around the (001) surface, and the roughening transition affects the size of locally merged steps (step droplets).

  17. Synthetic receiver function profiles through the upper mantle and the transition zone for upwelling scenarios

    Science.gov (United States)

    Nagel, Thorsten; Düsterhöft, Erik; Schiffer, Christian

    2017-04-01

    We investigate the signature relevant mantle lithologies leave in the receiver function record for different adiabatic thermal gradients down to 800 kilometers depth. The parameter space is chosen to target the visibility of upwelling mantle (a plume). Seismic velocities for depleted mantle, primitive mantle, and three pyroxenites are extracted from thermodynamically calculated phases diagrams, which also provide the adiabatic decompression paths. Results suggest that compositional variations, i.e. the presence or absence of considerable amounts of pyroxenites in primitive mantle should produce a clear footprint while horizontal differences in thermal gradients for similar compositions might be more subtle. Peridotites best record the classic discontinuities at around 410 and 650 kilometers depth, which are associated with the olivin-wadsleyite and ringwoodite-perovskite transitions, respectively. Pyroxenites, instead, show the garnet-perovskite transition below 700 kilometers depth and SiO2-supersaturated compositions like MORB display the coesite-stishovite transition between 300 and 340 kilometers depth. The latter shows the strongest temperature-depth dependency of all significant transitions potentially allowing to infer information about the thermal state if the mantle contains a sufficient fraction of MORB-like compositions. For primitive and depleted mantle compositions, the olivin-wadsleyite transition shows a certain temperature-depth dependency reflected in slightly larger delay times for higher thermal gradients. The lower-upper-mantle discontinuity, however, is predicted to display larger delay times for higher thermal gradients although the associated assemblage transition occurs at shallower depths thus requiring a very careful depth migration if a thermal anomaly should be recognized. This counterintuitive behavior results from the downward replacement of the assemblage wadsleyite+garnet with the assemblage garnet+periclase at high temperatures

  18. ACUTE ZONAL OCCULT OUTER RETINOPATHY: Structural and Functional Analysis Across the Transition Zone Between Healthy and Diseased Retina.

    Science.gov (United States)

    Duncker, Tobias; Lee, Winston; Jiang, Fan; Ramachandran, Rithambara; Hood, Donald C; Tsang, Stephen H; Sparrow, Janet R; Greenstein, Vivienne C

    2018-01-01

    To assess structure and function across the transition zone (TZ) between relatively healthy and diseased retina in acute zonal occult outer retinopathy. Six patients (6 eyes; age 22-71 years) with acute zonal occult outer retinopathy were studied. Spectral-domain optical coherence tomography, fundus autofluorescence, near-infrared reflectance, color fundus photography, and fundus perimetry were performed and images were registered to each other. The retinal layers of the spectral-domain optical coherence tomography scans were segmented and the thicknesses of two outer retinal layers, that is, the total receptor and outer segment plus layers, and the retinal nerve fiber layer were measured. All eyes showed a TZ on multimodal imaging. On spectral-domain optical coherence tomography, the TZ was in the nasal retina at varying distances from the fovea. For all eyes, it was associated with loss of the ellipsoid zone band, significant thinning of the two outer retinal layers, and in three eyes with thickening of the retinal nerve fiber layer. On fundus autofluorescence, all eyes had a clearly demarcated peripapillary area of abnormal fundus autofluorescence delimited by a border of high autofluorescence; the latter was associated with loss of the ellipsoid zone band and with a change from relatively normal to markedly decreased or nonrecordable visual sensitivity on fundus perimetry. The results of multimodal imaging clarified the TZ in acute zonal occult outer retinopathy. The TZ was outlined by a distinct high autofluorescence border that correlated with loss of the ellipsoid zone band on spectral-domain optical coherence tomography. However, in fundus areas that seemed healthy on fundus autofluorescence, thinning of the outer retinal layers and thickening of the retinal nerve fiber layer were observed near the TZ. The TZ was also characterized by a decrease in visual sensitivity.

  19. Counterclockwise and Clockwise Rotation of QRS Transitional Zone: Prospective Correlates of Change and Time-Varying Associations With Cardiovascular Outcomes.

    Science.gov (United States)

    Patel, Siddharth; Kwak, Lucia; Agarwal, Sunil K; Tereshchenko, Larisa G; Coresh, Josef; Soliman, Elsayed Z; Matsushita, Kunihiro

    2017-11-03

    A few studies have recently reported clockwise and counterclockwise rotations of QRS transition zone as predictors of mortality. However, their prospective correlates and associations with individual cardiovascular disease (CVD) outcomes are yet to be investigated. Among 13 567 ARIC (Atherosclerosis Risk in Communities) study participants aged 45 to 64 years, we studied key correlates of changes in the status of clockwise and counterclockwise rotation over time as well as the association of rotation status with incidence of coronary heart disease (2408 events), heart failure (2196 events), stroke (991 events), composite CVD (4124 events), 898 CVD deaths, and 3469 non-CVD deaths over 23 years of follow-up. At baseline, counterclockwise rotation was most prevalent (52.9%), followed by no (40.5%) and clockwise (6.6%) rotation. Of patients with no rotation, 57.9% experienced counterclockwise or clockwise rotation during follow-up, with diabetes mellitus and black race significantly predicting clockwise and counterclockwise conversion, respectively. Clockwise rotation was significantly associated with higher risk of heart failure (hazard ratio, 1.20; 95% confidence interval [CI], 1.02-1.41) and non-CVD death (hazard ratio, 1.28; 95% CI, 1.12-1.46) after adjusting for potential confounders including other ECG parameters. On the contrary, counterclockwise rotation was significantly related to lower risk of composite CVD (hazard ratio, 0.93; 95% CI, 0.87-0.99]), CVD mortality (hazard ratio, 0.76; 95% CI, 0.65-0.88), and non-CVD deaths (hazard ratio, 0.92; 95% CI, 0.85-0.99 [borderline significance with heart failure]). Counterclockwise rotation, the most prevalent QRS transition zone pattern, demonstrated the lowest risk of CVD and mortality, whereas clockwise rotation was associated with the highest risk of heart failure and non-CVD mortality. These results have implications on how to interpret QRS transition zone rotation when ECG was recorded. © 2017 The Authors

  20. A Bayesian approach to infer the radial distribution of temperature and anisotropy in the transition zone from seismic data

    Science.gov (United States)

    Drilleau, M.; Beucler, E.; Mocquet, A.; Verhoeven, O.; Moebs, G.; Burgos, G.; Montagner, J.

    2013-12-01

    Mineralogical transformations and matter transfers within the Earth's mantle make the 350-1000 km depth range (considered here as the mantle transition zone) highly heterogeneous and anisotropic. Most of the 3-D global tomographic models are anchored on small perturbations from 1-D models such as PREM, and are secondly interpreted in terms of temperature and composition distributions. However, the degree of heterogeneity in the transition zone can be strong enough so that the concept of a 1-D reference seismic model may be addressed. To avoid the use of any seismic reference model, we developed a Markov chain Monte Carlo algorithm to directly interpret surface wave dispersion curves in terms of temperature and radial anisotropy distributions, considering a given composition of the mantle. These interpretations are based on laboratory measurements of elastic moduli and Birch-Murnaghan equation of state. An originality of the algorithm is its ability to explore both smoothly varying models and first-order discontinuities, using C1-Bézier curves, which interpolate the randomly chosen values for depth, temperature and radial anisotropy. This parameterization is able to generate a self-adapting parameter space exploration while reducing the computing time. Using a Bayesian exploration, the probability distributions on temperature and anisotropy are governed by uncertainties on the data set. The method was successfully applied to both synthetic data and real dispersion curves. Surface wave measurements along the Vanuatu- California path suggest a strong anisotropy above 400 km depth which decreases below, and a monotonous temperature distribution between 350 and 1000 km depth. On the contrary, a negative shear wave anisotropy of about 2 % is found at the top of the transition zone below Eurasia. Considering compositions ranging from piclogite to pyrolite, the overall temperature profile and temperature gradient are higher for the continental path than for the oceanic

  1. Temporary streams in temperate zones: recognizing, monitoring and restoring transitional aquatic-terrestrial ecosystems

    OpenAIRE

    Stubbington, Rachel; England, Judy; Wood, Paul J.; Sefton, Catherine E.M.

    2017-01-01

    Temporary streams are defined by periodic flow cessation, and may experience partial or complete loss of surface water. The ecology and hydrology of these transitional aquatic-terrestrial ecosystems have received unprecedented attention in recent years. Research has focussed on the arid, semi-arid, and Mediterranean regions in which temporary systems are the dominant stream type, and those in cooler, wetter temperate regions with an oceanic climate influence are also receiving increasing atte...

  2. Mutations in DZIP1L, which encodes a ciliary transition zone protein, cause autosomal recessive polycystic kidney disease

    Science.gov (United States)

    Lu, Hao; Galeano, Maria C. Rondón; Ott, Elisabeth; Kaeslin, Geraldine; Kausalya, P. Jaya; Kramer, Carina; Ortiz-Brüchle, Nadina; Hilger, Nadescha; Metzis, Vicki; Hiersche, Milan; Tay, Shang Yew; Tunningley, Robert; Vij, Shubha; Courtney, Andrew D.; Whittle, Belinda; Wühl, Elke; Vester, Udo; Hartleben, Björn; Neuber, Steffen; Frank, Valeska; Little, Melissa H.; Epting, Daniel; Papathanasiou, Peter; Perkins, Andrew C.; Wright, Graham D.; Hunziker, Walter; Gee, Heon Yung; Otto, Edgar A.; Zerres, Klaus; Hildebrandt, Friedhelm; Roy, Sudipto; Wicking, Carol; Bergmann, Carsten

    2017-01-01

    Autosomal recessive polycystic kidney disease (ARPKD), usually considered to be a genetically homogeneous disease caused by mutations in PKHD1, has been associated with ciliary dysfunction. Here, we describe mutations in the DAZ interacting protein 1-like (DZIP1L) gene in patients with ARPKD, findings we have further validated by loss-of-function studies in mice and zebrafish. DZIP1L localizes to centrioles and at the distal end of basal bodies, and interacts with septin2, a protein implicated in maintenance of the periciliary diffusion barrier at the ciliary transition zone. Consistent with a defect in the diffusion barrier, we found that the ciliary membrane translocation of the PKD proteins, polycystin-1 and −2, is compromised in DZIP1L mutant cells. Together, these data provide the first conclusive evidence that ARPKD is not a homogeneous disorder, and establishes DZIP1L as a second gene involved in its pathogenesis. PMID:28530676

  3. Mutations in DZIP1L, which encodes a ciliary-transition-zone protein, cause autosomal recessive polycystic kidney disease.

    Science.gov (United States)

    Lu, Hao; Galeano, Maria C Rondón; Ott, Elisabeth; Kaeslin, Geraldine; Kausalya, P Jaya; Kramer, Carina; Ortiz-Brüchle, Nadina; Hilger, Nadescha; Metzis, Vicki; Hiersche, Milan; Tay, Shang Yew; Tunningley, Robert; Vij, Shubha; Courtney, Andrew D; Whittle, Belinda; Wühl, Elke; Vester, Udo; Hartleben, Björn; Neuber, Steffen; Frank, Valeska; Little, Melissa H; Epting, Daniel; Papathanasiou, Peter; Perkins, Andrew C; Wright, Graham D; Hunziker, Walter; Gee, Heon Yung; Otto, Edgar A; Zerres, Klaus; Hildebrandt, Friedhelm; Roy, Sudipto; Wicking, Carol; Bergmann, Carsten

    2017-07-01

    Autosomal recessive polycystic kidney disease (ARPKD), usually considered to be a genetically homogeneous disease caused by mutations in PKHD1, has been associated with ciliary dysfunction. Here, we describe mutations in DZIP1L, which encodes DAZ interacting protein 1-like, in patients with ARPKD. We further validated these findings through loss-of-function studies in mice and zebrafish. DZIP1L localizes to centrioles and to the distal ends of basal bodies, and interacts with septin2, a protein implicated in maintenance of the periciliary diffusion barrier at the ciliary transition zone. In agreement with a defect in the diffusion barrier, we found that the ciliary-membrane translocation of the PKD proteins polycystin-1 and polycystin-2 is compromised in DZIP1L-mutant cells. Together, these data provide what is, to our knowledge, the first conclusive evidence that ARPKD is not a homogeneous disorder and further establish DZIP1L as a second gene involved in ARPKD pathogenesis.

  4. Variability and Dynamics of Dissolved Oxygen in the Transition Zone of the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Jonasson, Lars

    information about the seasonal to decadal oxygen variations in the bottom water of the Kattegat, the Danish Straits, the Sound and the Western Baltic Sea and investigates the relative importance of physical and biogeochemical processes, climate change and nutrient load reductions on the oxygen variability......The bottom water in the transition zone of the North Sea and Baltic Sea suffers from seasonal hypoxia, usually during late summer and autumn. Hypoxia is a natural phenomenon in this region because of the strong vertical stratification which prevents the bottom water to be ventilated by atmospheric...... concentrations by 15-30 μmol O2 l−1 yr−1 while the reduced nutrient concentration has increased the oxygen concentration with approximately the same amount. Thus, the positive effect on oxygen conditions from reduced nutrient concentrations have been counteracted by increased water temperatures. This has made...

  5. OSO-8 observations of the impulsive phase of solar flares in the transition-zone and corona

    Science.gov (United States)

    Lites, B. W.; Bruner, E. C., Jr.; Wolfson, C. J.

    1981-01-01

    Several solar flares were observed from their onset in C IV 1548.2 A and 1-8 A X-rays using instruments on OSO-8. It is found that impulsive brightening in C IV is often accompanied by redshifts, interpreted as downflows, of the order of 80 km/s. The maximum soft X-ray intensity usually arrives several minutes after the maximum C IV intensity. The most energetic C IV event observed shows a small blueshift just before reaching maximum intensity; estimates of the mass flux associated with this upflow through the transition zone are consistent with the increase of mass in the coronal loops as observed in soft X-rays. Finally, it is suggested that the frequent occurrence of violent dynamical processes at the onset of the flare is associated with the initial energy release mechanism.

  6. Simulation of groundwater flow pathlines and freshwater/saltwater transition zone movement, Manhasset Neck, Nassau County, New York

    Science.gov (United States)

    Misut, Paul; Aphale, Omkar

    2014-01-01

    A density-dependent groundwater flow and solute transport model of Manhasset Neck, Long Island, New York, was used to analyze (1) the effects of seasonal stress on the position of the freshwater/saltwater transition zone and (2) groundwater flowpaths. The following were used in the simulation: 182 transient stress periods, representing the historical record from 1920 to 2011, and 44 transient stress periods, representing future hypothetical conditions from 2011 to 2030. Simulated water-level and salinity (chloride concentration) values are compared with values from a previously developed two-stress-period (1905–1944 and 1945–2005) model. The 182-stress-period model produced salinity (chloride concentration) values that more accurately matched the observed salinity (chloride concentration) values in response to hydrologic stress than did the two-stress-period model, and salinity ranged from zero to about 3 parts per thousand (equivalent to zero to 1,660 milligrams per liter chloride). The 182-stress-period model produced improved calibration statistics of water-level measurements made throughout the study area than did the two-stress-period model, reducing the Lloyd aquifer root mean square error from 7.0 to 5.2 feet. Decreasing horizontal and vertical hydraulic conductivities (fixed anisotropy ratio) of the Lloyd and North Shore aquifers by 20 percent resulted in nearly doubling the simulated salinity(chloride concentration) increase at Port Washington observation well N12508. Groundwater flowpath analysis was completed for 24 production wells to delineate water source areas. The freshwater/saltwater transition zone moved toward and(or) away from wells during future hypothetical scenarios.

  7. Could the peristaltic transition zone be caused by non-uniform esophageal muscle fiber architecture? A simulation study.

    Science.gov (United States)

    Kou, W; Pandolfino, J E; Kahrilas, P J; Patankar, N A

    2017-06-01

    Based on a fully coupled computational model of esophageal transport, we analyzed how varied esophageal muscle fiber architecture and/or dual contraction waves (CWs) affect bolus transport. Specifically, we studied the luminal pressure profile in those cases to better understand possible origins of the peristaltic transition zone. Two groups of studies were conducted using a computational model. The first studied esophageal transport with circumferential-longitudinal fiber architecture, helical fiber architecture and various combinations of the two. In the second group, cases with dual CWs and varied muscle fiber architecture were simulated. Overall transport characteristics were examined and the space-time profiles of luminal pressure were plotted and compared. Helical muscle fiber architecture featured reduced circumferential wall stress, greater esophageal distensibility, and greater axial shortening. Non-uniform fiber architecture featured a peristaltic pressure trough between two high-pressure segments. The distal pressure segment showed greater amplitude than the proximal segment, consistent with experimental data. Dual CWs also featured a pressure trough between two high-pressure segments. However, the minimum pressure in the region of overlap was much lower, and the amplitudes of the two high-pressure segments were similar. The efficacy of esophageal transport is greatly affected by muscle fiber architecture. The peristaltic transition zone may be attributable to non-uniform architecture of muscle fibers along the length of the esophagus and/or dual CWs. The difference in amplitude between the proximal and distal pressure segments may be attributable to non-uniform muscle fiber architecture. © 2017 John Wiley & Sons Ltd.

  8. Comprehensive understanding of a deep transition zone from an unstable- to stable-slip regime of the megathrust interplate earthquake

    Science.gov (United States)

    Kato, A.; Iidaka, T.; Ikuta, R.; Yoshida, Y.; Katsumata, K.; Iwasaki, T.; Sakai, S.; Yamaoka, K.; Watanabe, T.; Kunitomo, T.; Yamazaki, F.; Tsumura, N.; Nozaki, K.; Okubo, M.; Suzuki, S.; Hirata, N.; Zhang, H.; Thurber, C. H.

    2009-12-01

    Most slow slips have occurred in the deep transition zone from an unstable- to stable-slip regime. Detailed knowledge about a deep transition zone is essentially important to understand the mechanism of the slow slips, and the stress concentration process to the source region of the megathrust interplate earthquake. We have conducted a very dense seismic observation in the Tokai-region from the April to the August in 2008 through a linear deployment of 75 portable stations, in Japan. The array extended from the bottom part of the source region of the Tokai earthquake to deep low-frequency earthquakes (LFE, ~ 35 km depth) including the long-term slow-slip region (~ 25 km depth). Here we present a high-resolution tomographic imaging of seismic velocities and highly-accurate hypocenters including LFEs, using first arrival data from the dense seismograph deployment. We manually picked the first arrivals of P- and S- waves from each waveform for about 700 earthquakes including about 20 LFEs observed by the dense array. Then, we applied the TomoDD-code [Zhang and Thurber, 2003] to the arrival data set, adding an accurate double-difference data estimated by a waveform cross-correlation technique. A low velocity (Vp, Vs) layer with high Poisson’s ratio is clearly imaged, and tilts to the northwestward with a low dip angle, which corresponds to the subducting oceanic crust of the Philippine Sea Slab. Although seismicity within the oceanic crust is significantly low, few earthquakes occur within the oceanic crust. The LFEs are linearly aligned along the top surface of the subducting oceanic crust at depths from 30 to 40 km. The Poisson’s ratio within the oceanic crust does not show significant depth-dependent increase beneath the linear alignment of LFEs. This result argues against a depth section of Poisson’s ratio obtained in the SW Japan [Shelly et al., 2006]. Beneath the LFEs, active cluster of slab earthquakes are horizontally distributed. At the depths greater

  9. Isotopic evidence for the spatial heterogeneity of the planktonic food webs in the transition zone between river and lake ecosystems

    Directory of Open Access Journals (Sweden)

    Hideyuki Doi

    2013-12-01

    Full Text Available Resources and organisms in food webs are distributed patchily. The spatial structure of food webs is important and critical to understanding their overall structure. However, there is little available information about the small-scale spatial structure of food webs. We investigated the spatial structure of food webs in a lake ecosystem at the littoral transition zone between an inflowing river and a lake. We measured the carbon isotope ratios of zooplankton and particulate organic matter (POM; predominantly phytoplankton in the littoral zone of a saline lake. Parallel changes in the δ 13C values of zooplankton and their respective POMs indicated that there is spatial heterogeneity of the food web in this study area. Lake ecosystems are usually classified at the landscape level as either pelagic or littoral habitats. However, we showed small-scale spatial heterogeneity among planktonic food webs along an environmental gradient. Stable isotope data is useful for detecting spatial heterogeneity of habitats, populations, communities, and ecosystems.

  10. A phylogeographic study of the endemic rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of Northern Madagascar.

    Science.gov (United States)

    Rakotoarisoa, Jean-Eric; Raheriarisena, Martin; Goodman, Steven M

    2013-01-01

    We conducted a mitochondrial phylogeographic study of the endemic dry forest rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of northern Madagascar (Loky-Manambato) and 2 surrounding regions (Ankarana and Analamerana). The main goal was to assess the evolutionary consequences on this taxon of the complex landscape features and Quaternary ecological vicissitudes. Three haplogroups were identified from the 215 specimens obtained from 15 populations. High levels of genetic diversity and significant genetic differentiation among populations were observed. The different geographical subdivisions of the study area by regions, by river catchment zones, and the physical distance between populations are not correlated with genetic patterns. In contrast, population structure is mostly explained by the geographic distribution of the samples among existing forest blocks. E. carletoni experienced a genetic bottleneck between 18 750 and 7500 years BP, which correlates with periods when moister climates existed on the island. Overall, our data suggest that the complex genetic patterns of E. carletoni can be explained by Quaternary climatic vicissitudes that resulted in habitat fluctuations between dry and humid forests, as well as subsequent human-induced fragmentation of forest habitat.

  11. Imprints from genetic drift and mutation imply relative divergence times across marine transition zones in a Pan European small pelagic fish (Sprattus sprattus)

    DEFF Research Database (Denmark)

    Limborg, Morten; Hanel, R.; Debes, P.

    2012-01-01

    .) by combining inference from both mtDNA and microsatellite genetic markers throughout the species’ distribution. We compared effects from genetic drift and mutation for both genetic markers in shaping genetic differentiation across four transition zones. Microsatellite markers revealed significant isolation...... by distance and a complex population structure across the species0 distribution (overall yST¼0.038, Po0.01). Across transition zones markers indicated larger effects of genetic drift over mutations in the northern distribution of sprat contrasting a stronger relative impact of mutation in the species...

  12. Sedimentology and geochemistry of early Proterozoic storm-dominated deposits in the transition zone from microbanded Kuruman to granular Griquatown iron-formation, Griqualand West

    International Nuclear Information System (INIS)

    Beukes, N.J.; Klein, C.

    1990-01-01

    A transition from microbanded Kuruman to granular Griquatown iron-formation is described in terms of sedimentological, petrographic, and geochemical characteristics, as well as whole rock carbon and oxygen isotopic compositions. Five major lithofacies are present in the Kuruman-Griquatown transition zone. The lithofacies are arranged in an upward coarsening sequence. It is concluded that the coarsening upward microbanded-granular iron-formation units in the Kuruman-Griquatown sequence represent shallowing upward storm-dominated deposits. 2 refs

  13. Validation of small Kepler transiting planet candidates in or near the habitable zone

    DEFF Research Database (Denmark)

    Torres, Guillermo; Kane, Stephen R.; Rowe, Jason F.

    2017-01-01

    A main goal of NASA's Kepler Mission is to establish the frequency of potentially habitable Earth-size planets (). Relatively few such candidates identified by the mission can be confirmed to be rocky via dynamical measurement of their mass. Here we report an effort to validate 18 of them...... statistically using the BLENDER technique, by showing that the likelihood they are true planets is far greater than that of a false positive. Our analysis incorporates follow-up observations including high-resolution optical and near-infrared spectroscopy, high-resolution imaging, and information from...... the analysis of the flux centroids of the Kepler observations themselves. Although many of these candidates have been previously validated by others, the confidence levels reported typically ignore the possibility that the planet may transit a star different from the target along the same line of sight...

  14. Contribution to the study of velocity fields of chromosphere and solar transition zone

    International Nuclear Information System (INIS)

    Artzner, C.

    1982-06-01

    The LPSP (Laboratoire de Physique Stellaire et Planetaire) experiment on board 0508 is described. The properties of the instrument are discussed together with their evolution with time. The chromospheric oscillations and transients were studied (sunspost and active regions, prominences, oscillations in the chromosphere, chromosphere-corona transition lines). Simultaneous time-resolved observations of the H Lα, Mg k 2795A, and Ca, K solar lines were made. They indicate that the temporal variations of wavelength of the reversal of the solar H Lα and Mg k lines are correlated. A narrow absorption on the red part of the solar H Lα profile was observed and attributed to atomic hydrogen of the nearby interplanetary gas [fr

  15. TEM Microstructure and Chemical Composition of Transition Zone Between Steel Tube and An Inconel 625 Weld Overlay Coating Produced by CMT Method

    Directory of Open Access Journals (Sweden)

    Rozmus-Górnikowska M.

    2017-06-01

    Full Text Available The aim of this work was to investigate the microstructure and chemical composition of the transition zone between 16Mo3 steel and Inconel 625 weld overlay coating produced by the Cold Metal Transfer (CMT method. Investigations were primarily carried out through transmission electron microscopy (TEM on thin foils prepared by FIB (Focus Ion Beam.

  16. Small ruminant feed systems: perceptions and practices in the transitional zone of Ghana

    Directory of Open Access Journals (Sweden)

    van der Zijpp Akke J

    2010-03-01

    and agronomic investigations into major feeds, the creation of non-cropping zones around village fringes and studies on labour demands of different feed systems are proposed. The insight gained in this study on farmers' perceptions and practices relating to small ruminant feeds could guide in the selection and introduction of feed innovations that fit into current feed systems to enhance adoption.

  17. Organization of the Zone of Transition between the Pretectum and the Thalamus, with Emphasis on the Pretectothalamic Lamina

    Directory of Open Access Journals (Sweden)

    Emmanuel Márquez-Legorreta

    2016-08-01

    Full Text Available The zone of transition between the pretectum, derived from prosomere 1, and the thalamus, derived from prosomere 2, is structurally complex and its understanding has been hampered by cytoarchitectural and terminological confusion. Herein, using a battery of complementary morphological approaches, including cytoarchitecture, myeloarchitecture and the expression of molecular markers, we pinpoint the features or combination of features that best characterize each nucleus of the pretectothalamic transitional zone of the rat. Our results reveal useful morphological criteria to identify and delineate, with unprecedented precision, several [mostly auditory] nuclei of the posterior group of the thalamus, namely the pretectothalamic lamina (PTL; formerly known as the posterior limitans nucleus, the medial division of the medial geniculate body (MGBm, the suprageniculate nucleus (SG, and the ethmoid, posterior triangular and posterior nuclei of the thalamus. The PTL is a sparsely-celled and fiber rich flattened nucleus apposed to the lateral surface of the anterior pretectal nucleus that marks the border between the pretectum and the thalamus; this structure stains selectively with the Wisteria floribunda agglutinin (WFA, and is essentially immunonegative for the calcium binding protein parvalbumin. The MGBm, located medial to the ventral division of the medial geniculate body, can be unequivocally identified by the large size of many of its neurons, its dark immunostaining for parvalbumin, and its rather selective staining for WFA. The SG, which extends for a considerable caudorostral distance and deviates progressively from the MGB, is characterized by its peculiar cytoarchitecture, the paucity of myelinated fibers, and the conspicuous absence of staining for calretinin; indeed, in many calretinin-stained sections, the SG stands out as a blank spot. Because most of these nuclei are small and show unique anatomical relationships, the information provided

  18. A Transition Zone Showing Highly Discontinuous or Alternating Levels of Stem Cell and Proliferation Markers Characterizes the Development of PTEN-Haploinsufficient Colorectal Cancer.

    Science.gov (United States)

    Arvai, Kevin J; Hsu, Ya-Hsuan; Lee, Lobin A; Jones, Dan

    2015-01-01

    Stepwise acquisition of oncogene mutations and deletion/inactivation of tumor suppressor genes characterize the development of colorectal cancer (CRC). These genetic events interact with discrete morphologic transitions from hyperplastic mucosa to adenomatous areas, followed by in situ malignant transformation and finally invasive carcinoma. The goal of this study was to identify tissue markers of the adenoma-carcinoma morphogenetic transitions in CRC. We analyzed the patterns of expression of growth regulatory and stem cell markers across these distinct morphologic transition zones in 735 primary CRC tumors. In 202 cases with preserved adenoma-adenocarcinoma transition, we identified, in 37.1% of cases, a zone of adenomatous epithelium, located immediately adjacent to the invasive component, that showed rapidly alternating intraglandular stretches of PTEN+ and PTEN- epithelium. This zone exactly overlapped with similar alternating expression of Ki-67 and inversely with the transforming growth factor-beta (TGF-β) growth regulator SMAD4. These zones also show parallel alternating levels and/or subcellular localization of multiple cancer stem/progenitor cell (CSC) markers, including β-catenin/CTNNB1, ALDH1, and CD44. PTEN was always re-expressed in the invasive tumor in these cases, unlike those with complete loss of PTEN expression. Genomic microarray analysis of CRC with prominent CSC-like expansions demonstrated a high frequency of PTEN genomic deletion/haploinsufficiency in tumors with CSC-like transition zones (62.5%) but not in tumors with downregulated but non-alternating PTEN expression (14.3%). There were no significant differences in the levels of KRAS mutation or CTNNB1 mutation in CSC-like tumors as compared to unselected CRC cases. In conclusion, we have identified a distinctive CSC-like pre-invasive transition zone in PTEN-haploinsufficient CRC that shows convergent on-off regulation of the PTEN/AKT, TGF-β/SMAD and Wnt/β-catenin pathways. This

  19. A Transition Zone Showing Highly Discontinuous or Alternating Levels of Stem Cell and Proliferation Markers Characterizes the Development of PTEN-Haploinsufficient Colorectal Cancer.

    Directory of Open Access Journals (Sweden)

    Kevin J Arvai

    Full Text Available Stepwise acquisition of oncogene mutations and deletion/inactivation of tumor suppressor genes characterize the development of colorectal cancer (CRC. These genetic events interact with discrete morphologic transitions from hyperplastic mucosa to adenomatous areas, followed by in situ malignant transformation and finally invasive carcinoma. The goal of this study was to identify tissue markers of the adenoma-carcinoma morphogenetic transitions in CRC.We analyzed the patterns of expression of growth regulatory and stem cell markers across these distinct morphologic transition zones in 735 primary CRC tumors. In 202 cases with preserved adenoma-adenocarcinoma transition, we identified, in 37.1% of cases, a zone of adenomatous epithelium, located immediately adjacent to the invasive component, that showed rapidly alternating intraglandular stretches of PTEN+ and PTEN- epithelium. This zone exactly overlapped with similar alternating expression of Ki-67 and inversely with the transforming growth factor-beta (TGF-β growth regulator SMAD4. These zones also show parallel alternating levels and/or subcellular localization of multiple cancer stem/progenitor cell (CSC markers, including β-catenin/CTNNB1, ALDH1, and CD44. PTEN was always re-expressed in the invasive tumor in these cases, unlike those with complete loss of PTEN expression. Genomic microarray analysis of CRC with prominent CSC-like expansions demonstrated a high frequency of PTEN genomic deletion/haploinsufficiency in tumors with CSC-like transition zones (62.5% but not in tumors with downregulated but non-alternating PTEN expression (14.3%. There were no significant differences in the levels of KRAS mutation or CTNNB1 mutation in CSC-like tumors as compared to unselected CRC cases.In conclusion, we have identified a distinctive CSC-like pre-invasive transition zone in PTEN-haploinsufficient CRC that shows convergent on-off regulation of the PTEN/AKT, TGF-β/SMAD and Wnt

  20. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary

    Science.gov (United States)

    Amarilla, Leonardo D.; Anton, Ana M.; Chiapella, Jorge O.; Manifesto, María M.; Angulo, Diego F.; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species’ range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2–1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity. PMID:26110533

  1. Layered crust-mantle transition zone below a large crustal intrusion in the Norwegian-Danish basin

    DEFF Research Database (Denmark)

    Sandrin, Alessandro; Nielsen, Lars; Thybo, Hans

    2009-01-01

    the lowermost crust (7.7 km/s) and the uppermost mantle (7.9-8.0 km/s). The seismic data show a "ringing" Moho below the western part of the intrusion. The coda trailing the main PmP reflection is about 1.0 s long and is composed of 4-5 wavelets. We demonstrate that this feature may be explained by a layered......The crust and uppermost mantle below the large positive gravity anomaly in the central part of the Norwegian-Danish Basin, the Silkeborg Gravity High (SGH), is investigated using controlled source seismic data. A more than 80 km long and ~ 20 km thick intrusion is interpreted. The seismic velocity...... transition zone between 30 and 35 km depth, where high-velocity layers of mantle affinity (7.9-8.05 km/s) alternate with layers of typical lower crustal velocity (6.7-7.3 km/s). The characteristics of this layering, which causes thePmP coda, are modelled by matching synthetic seismograms to the observed data...

  2. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary.

    Directory of Open Access Journals (Sweden)

    Leonardo D Amarilla

    Full Text Available The South American Transition Zone (SATZ is a biogeographic area in which not only orogeny (Andes uplift and climate events (aridification since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species' range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2-1.2 Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

  3. Design and Development of Maize Dehusker cum Sheller: A Technology for Northern Transition Zone of Karnataka, India

    Science.gov (United States)

    Chilur, Rudragouda; Kumar, Sushilendra

    2018-06-01

    The Maize ( Zea mays L.) crop is one of the most important cereal in agricultural production systems of Northern Transition Zone (Hyderabad-Karnataka region) in India. These Hyderabad Karnataka farmers (small-medium) are lack of economic technologies with maize dehusking and shelling, which fulfils the two major needs as crops and as livestock in farming. The portable medium size (600 kg/h capacity) electric motor (2.23 kW) operated Maize Dehusker cum Sheller (MDS) was designed to resolve the issue by considering engineering properties of maize. The developed trapezium shaped MDS machine having overall dimensions (length × (top and bottom) × height) of 1200 × (500 and 610) × 810 mm. The selected operational parameters viz, cylinder peripheral speed (7.1 m/s), concave clearance (25 mm) and feed rate (600 kg/h) were studied for machine-performance and seed-quality parameters. The performance of machine under these parameters showed the dehusking efficiency of 99.56%, shelling efficiency of 98.01%, cleaning efficiency of 99.11%, total loss of 3.63% machine capacity of 527.11 kg/kW-h and germination percentage of 98.93%. Overall machine performance was found satisfactory for maize dehusking cum shelling operation as well as to produce the maize grains for seeding purpose.

  4. Influence of aggregate size, water cement ratio and age on the microstructure of the interfacial transition zone

    International Nuclear Information System (INIS)

    Elsharief, Amir; Cohen, Menashi D.; Olek, Jan

    2003-01-01

    This paper presents the results of an investigation on the effect of water-cement ratio (w/c), aggregate size, and age on the microstructure of the interfacial transition zone (ITZ) between normal weight aggregate and the bulk cement paste. Backscattered electron images (BSE) obtained by scanning electron microscope were used to characterize the ITZ microstructure. The results suggest that the w/c plays an important role in controlling the microstructure of the ITZ and its thickness. Reducing w/c from 0.55 to 0.40 resulted in an ITZ with characteristics that are not distinguishable from those of the bulk paste as demonstrated by BSE images. Aggregate size appears to have an important influence on the ITZ characteristics. Reducing the aggregate size tends to reduce the ITZ porosity. The evolution of the ITZ microstructure relative to that of the bulk paste appears to depend on the initial content of the unhydrated cement grains (UH). The results suggest that the presence of a relatively low amount of UH in the ITZ at early age may cause the porosity of the ITZ, relative to that of the bulk paste, to increase with time. The presence of relatively large amount of UH in the ITZ at early ages may cause its porosity, relative to that of the bulk paste, to decrease with time

  5. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary.

    Science.gov (United States)

    Amarilla, Leonardo D; Anton, Ana M; Chiapella, Jorge O; Manifesto, María M; Angulo, Diego F; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species' range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2-1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

  6. Prostate-specific membrane antigen PET/MRI validation of MR textural analysis for detection of transition zone prostate cancer

    International Nuclear Information System (INIS)

    Bates, Anthony; Miles, Kenneth

    2017-01-01

    To validate MR textural analysis (MRTA) for detection of transition zone (TZ) prostate cancer through comparison with co-registered prostate-specific membrane antigen (PSMA) PET-MR. Retrospective analysis was performed for 30 men who underwent simultaneous PSMA PET-MR imaging for staging of prostate cancer. Thirty texture features were derived from each manually contoured T2-weighted, transaxial, prostatic TZ using texture analysis software that applies a spatial band-pass filter and quantifies texture through histogram analysis. Texture features of the TZ were compared to PSMA expression on the corresponding PET images. The Benjamini-Hochberg correction controlled the false discovery rate at <5%. Eighty-eight T2-weighted images in 18 patients demonstrated abnormal PSMA expression within the TZ on PET-MR. 123 images were PSMA negative. Based on the corrected p-value of 0.005, significant differences between PSMA positive and negative slices were found for 16 texture parameters: Standard deviation and mean of positive pixels for all spatial filters (p = <0.0001 for both at all spatial scaling factor (SSF) values) and mean intensity following filtration for SSF 3-6 mm (p = 0.0002-0.0018). Abnormal expression of PSMA within the TZ is associated with altered texture on T2-weighted MR, providing validation of MRTA for the detection of TZ prostate cancer. (orig.)

  7. Prostate-specific membrane antigen PET/MRI validation of MR textural analysis for detection of transition zone prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Anthony [Princess Alexandra Hospital, Brisbane (Australia); Miles, Kenneth [Princess Alexandra Hospital, Department of Diagnostic Radiology, Brisbane, QLD (Australia); University College London, Institute of Nuclear Medicine, London (United Kingdom)

    2017-12-15

    To validate MR textural analysis (MRTA) for detection of transition zone (TZ) prostate cancer through comparison with co-registered prostate-specific membrane antigen (PSMA) PET-MR. Retrospective analysis was performed for 30 men who underwent simultaneous PSMA PET-MR imaging for staging of prostate cancer. Thirty texture features were derived from each manually contoured T2-weighted, transaxial, prostatic TZ using texture analysis software that applies a spatial band-pass filter and quantifies texture through histogram analysis. Texture features of the TZ were compared to PSMA expression on the corresponding PET images. The Benjamini-Hochberg correction controlled the false discovery rate at <5%. Eighty-eight T2-weighted images in 18 patients demonstrated abnormal PSMA expression within the TZ on PET-MR. 123 images were PSMA negative. Based on the corrected p-value of 0.005, significant differences between PSMA positive and negative slices were found for 16 texture parameters: Standard deviation and mean of positive pixels for all spatial filters (p = <0.0001 for both at all spatial scaling factor (SSF) values) and mean intensity following filtration for SSF 3-6 mm (p = 0.0002-0.0018). Abnormal expression of PSMA within the TZ is associated with altered texture on T2-weighted MR, providing validation of MRTA for the detection of TZ prostate cancer. (orig.)

  8. Feeding habit of the Brazilian tapir, Tapirus terrestris (Perissodactyla: Tapiridae in a vegetation transition zone in south-eastern Brazil

    Directory of Open Access Journals (Sweden)

    Sônia A. Talamoni

    2009-06-01

    Full Text Available Tapirs are considered generalist herbivores and the differences in the proportions of dietary items are often attributed to differences in the habitats where individuals live. This study characterized the feeding habit of Tapirus terrestris (Linnaeus, 1758 in a nature reserve in south-eastern Brazil, located in a region considered a transition zone between the Cerrado (Brazilian savanna and the Atlantic Forest biomes. Fecal samples from T. terrestris individuals were collected monthly at six sampling areas that encompassed a total of 242.22 ha. There were 147 fresh samples found (77 during the dry season and 70 during the wet season. The diet of the tapirs in this reserve was characterized by the prevalent browsing on leaves and stems. There was a low frequency of fruit seeds in the diet of the tapirs during both the wet and dry seasons. However, in the dry season a higher percentage of samples containing seeds was observed. Fruits of Rubiaceae, Solanaceae, and Annonaceae were most consumed during the dry season. Most of the fruit seeds found presented small mean diameter (3.7-8.4 mm and most of the fruits were capsules and dry fruits. The characteristics of the fruits consumed by the tapirs indicate that they forage in the lower forest stratum and upon species from Cerrado. Additionally, Psidium myrtoides O. Berg. clusters found in the study site suggest that the tapirs may be acting as dispersal agents of this species.

  9. Design and Development of Maize Dehusker cum Sheller: A Technology for Northern Transition Zone of Karnataka, India

    Science.gov (United States)

    Chilur, Rudragouda; Kumar, Sushilendra

    2018-02-01

    The Maize (Zea mays L.) crop is one of the most important cereal in agricultural production systems of Northern Transition Zone (Hyderabad-Karnataka region) in India. These Hyderabad Karnataka farmers (small-medium) are lack of economic technologies with maize dehusking and shelling, which fulfils the two major needs as crops and as livestock in farming. The portable medium size (600 kg/h capacity) electric motor (2.23 kW) operated Maize Dehusker cum Sheller (MDS) was designed to resolve the issue by considering engineering properties of maize. The developed trapezium shaped MDS machine having overall dimensions (length × (top and bottom) × height) of 1200 × (500 and 610) × 810 mm. The selected operational parameters viz, cylinder peripheral speed (7.1 m/s), concave clearance (25 mm) and feed rate (600 kg/h) were studied for machine-performance and seed-quality parameters. The performance of machine under these parameters showed the dehusking efficiency of 99.56%, shelling efficiency of 98.01%, cleaning efficiency of 99.11%, total loss of 3.63% machine capacity of 527.11 kg/kW-h and germination percentage of 98.93%. Overall machine performance was found satisfactory for maize dehusking cum shelling operation as well as to produce the maize grains for seeding purpose.

  10. 33 CFR 165.110 - Safety and Security Zone; Liquefied Natural Gas Carrier Transits and Anchorage Operations, Boston...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zone... Limited Access Areas First Coast Guard District § 165.110 Safety and Security Zone; Liquefied Natural Gas.... The following areas are safety and security zones: (1) Vessels underway. All navigable waters of the...

  11. Crustal structure beneath two seismic stations in the Sunda-Banda arc transition zone derived from receiver function analysis

    Energy Technology Data Exchange (ETDEWEB)

    Syuhada, E-mail: hadda9@gmail.com [Graduate Research on Earthquake and Active Tectonics (GREAT), Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132 (Indonesia); Research Centre for Physics - Indonesian Institute of Sciences (LIPI), Kompleks Puspiptek Serpong, Tangsel 15314, Banten Indonesia (Indonesia); Hananto, Nugroho D.; Handayani, Lina [Research Centre for Geotechnology - Indonesian Institute of Sciences (LIPI), Jl. Sangkuriang (Kompleks LIPI) Bandung 40135 (Indonesia); Puspito, Nanang T; Yudistira, Tedi [Faculty of Mining and Petroleum Engineering ITB, Jalan Ganesha 10, Bandung 40132 (Indonesia); Anggono, Titi [Research Centre for Physics - Indonesian Institute of Sciences (LIPI), Kompleks Puspiptek Serpong, Tangsel 15314, Banten Indonesia (Indonesia)

    2015-04-24

    We analyzed receiver functions to estimate the crustal thickness and velocity structure beneath two stations of Geofon (GE) network in the Sunda-Banda arc transition zone. The stations are located in two different tectonic regimes: Sumbawa Island (station PLAI) and Timor Island (station SOEI) representing the oceanic and continental characters, respectively. We analyzed teleseismic events of 80 earthquakes to calculate the receiver functions using the time-domain iterative deconvolution technique. We employed 2D grid search (H-κ) algorithm based on the Moho interaction phases to estimate crustal thickness and Vp/Vs ratio. We also derived the S-wave velocity variation with depth beneath both stations by inverting the receiver functions. We obtained that beneath station PLAI the crustal thickness is about 27.8 km with Vp/Vs ratio 2.01. As station SOEI is covered by very thick low-velocity sediment causing unstable solution for the inversion, we modified the initial velocity model by adding the sediment thickness estimated using high frequency content of receiver functions in H-κ stacking process. We obtained the crustal thickness is about 37 km with VP/Vs ratio 2.2 beneath station SOEI. We suggest that the high Vp/Vs in station PLAI may indicate the presence of fluid ascending from the subducted plate to the volcanic arc, whereas the high Vp/Vs in station SOEI could be due to the presence of sediment and rich mafic composition in the upper crust and possibly related to the serpentinization process in the lower crust. We also suggest that the difference in velocity models and crustal thicknesses between stations PLAI and SOEI are consistent with their contrasting tectonic environments.

  12. Diverse effects of crop distribution and climate change on crop production in the agro-pastoral transitional zone of China

    Science.gov (United States)

    Qiao, Jianmin; Yu, Deyong; Wang, Qianfeng; Liu, Yupeng

    2018-06-01

    Both crop distribution and climate change are important drivers for crop production and can affect food security, which is an important requirement for sustainable development. However, their effects on crop production are confounded and warrant detailed investigation. As a key area for food production that is sensitive to climate change, the agro-pastoral transitional zone (APTZ) plays a significant role in regional food security. To investigate the respective effects of crop distribution and climate change on crop production, the well-established GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted with different scenario designs in this study. From 1980 to 2010, the crop distribution for wheat, maize, and rice witnessed a dramatic change due to agricultural policy adjustments and ecological engineering-related construction in the APTZ. At the same time, notable climate change was observed. The simulation results indicated that the climate change had a positive impact on the crop production of wheat, maize, and rice, while the crop distribution change led to an increase in the production of maize and rice, but a decrease in the wheat production. Comparatively, crop distribution change had a larger impact on wheat (-1.71 × 106 t) and maize (8.53 × 106 t) production, whereas climate change exerted a greater effect on rice production (0.58 × 106 t), during the period from 1980 to 2010 in the APTZ. This study is helpful to understand the mechanism of the effects of crop distribution and climate change on crop production, and aid policy makers in reducing the threat of future food insecurity.

  13. Diverse effects of crop distribution and climate change on crop production in the agro-pastoral transitional zone of China

    Science.gov (United States)

    Qiao, Jianmin; Yu, Deyong; Wang, Qianfeng; Liu, Yupeng

    2017-07-01

    Both crop distribution and climate change are important drivers for crop production and can affect food security, which is an important requirement for sustainable development. However, their effects on crop production are confounded and warrant detailed investigation. As a key area for food production that is sensitive to climate change, the agro-pastoral transitional zone (APTZ) plays a significant role in regional food security. To investigate the respective effects of crop distribution and climate change on crop production, the well-established GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted with different scenario designs in this study. From 1980 to 2010, the crop distribution for wheat, maize, and rice witnessed a dramatic change due to agricultural policy adjustments and ecological engineering-related construction in the APTZ. At the same time, notable climate change was observed. The simulation results indicated that the climate change had a positive impact on the crop production of wheat, maize, and rice, while the crop distribution change led to an increase in the production of maize and rice, but a decrease in the wheat production. Comparatively, crop distribution change had a larger impact on wheat (-1.71 × 106 t) and maize (8.53 × 106 t) production, whereas climate change exerted a greater effect on rice production (0.58 × 106 t), during the period from 1980 to 2010 in the APTZ. This study is helpful to understand the mechanism of the effects of crop distribution and climate change on crop production, and aid policy makers in reducing the threat of future food insecurity.

  14. Tc(VII) and Cr(VI) Interaction with Naturally Reduced Ferruginous Smectite from a Redox Transition Zone.

    Science.gov (United States)

    Qafoku, Odeta; Pearce, Carolyn I; Neumann, Anke; Kovarik, Libor; Zhu, Mengqiang; Ilton, Eugene S; Bowden, Mark E; Resch, Charles T; Arey, Bruce W; Arenholz, Elke; Felmy, Andrew R; Rosso, Kevin M

    2017-08-15

    Fe(II)-rich clay minerals found in subsurface redox transition zones (RTZs) can serve as important sources of electron equivalents limiting the transport of redox-active contaminants. While most laboratory reactivity studies are based on reduced model clays, the reactivity of naturally reduced field samples remains poorly explored. Characterization of the clay size fraction of a fine-grained unit from the RTZ interface at the Hanford site, Washington, including mineralogy, crystal chemistry, and Fe(II)/(III) content, indicates that ferruginous montmorillonite is the dominant mineralogical component. Oxic and anoxic fractions differ significantly in Fe(II) natural content, but Fe TOTAL remains constant, demonstrating no Fe loss during its reduction-oxidation cyclings. At native pH of 8.6, the anoxic fraction, despite its significant Fe(II), ∼23% of Fe TOTAL , exhibits minimal reactivity with TcO 4 - and CrO 4 2- and much slower reaction kinetics than those measured in studies with biologically/chemically reduced model clays. Reduction capacity is enhanced by added/sorbed Fe(II) (if Fe(II) SORBED > 8% clay Fe(II) LABILE ); however, the kinetics of this conceptually surface-mediated reaction remain sluggish. Surface-sensitive Fe L-edge X-ray absorption spectroscopy shows that Fe(II) SORBED and the resulting reducing equivalents are not available in the outermost few nanometers of clay surfaces. Slow kinetics thus appear related to diffusion-limited access to electron equivalents retained within the clay mineral structure.

  15. Biogeochemical cycles at the sulfate-methane transition zone (SMTZ) and geochemical characteristics of the pore fluids offshore southwestern Taiwan

    Science.gov (United States)

    Hu, Ching-Yi; Frank Yang, Tsanyao; Burr, George S.; Chuang, Pei-Chuan; Chen, Hsuan-Wen; Walia, Monika; Chen, Nai-Chen; Huang, Yu-Chun; Lin, Saulwood; Wang, Yunshuen; Chung, San-Hsiung; Huang, Chin-Da; Chen, Cheng-Hong

    2017-11-01

    In this study, we used pore water dissolved inorganic carbon (DIC), SO42-, Ca2+ and Mg2+ gradients at the sulfate-methane transition zone (SMTZ) to estimate biogeochemical fluxes for cored sediments collected offshore SW Taiwan. Net DIC flux changes (ΔDIC-Prod) were applied to determine the proportion of sulfate consumption by organic matter oxidation (heterotrophic sulfate reduction) and anaerobic oxidation of methane (AOM), and to determine reliable CH4 fluxes at the SMTZ. Our results show that SO42- profiles are mainly controlled by AOM rather than heterotrophic sulfate reduction. Refinement of CH4 flux estimates enhance our understanding of methane abundance from deep carbon reservoirs to the SMTZ. Concentrations of chloride (Cl-), bromide (Br-) and iodide (I-) dissolved in pore water were used to identify potential sources that control fluid compositions and the behavior of dissolved ions. Constant Cl- concentrations throughout ∼30 m sediment suggest no influence of gas hydrates for the compositions within the core. Bromide (Br-) and Iodine (I-) concentrations increase with sediment depth. The I-/Br- ratio appears to reflect organic matter degradation. SO42- concentrations decrease with sediment depth at a constant rate, and sediment depth profiles of Br- and I- concentrations suggests diffusion as the main transport mechanism. Therefore diffusive flux calculations are reasonable. Coring sites with high CH4 fluxes are more common in the accretionary wedge, amongst thrust faults and fractures, than in the passive continental margin offshore southwestern Taiwan. AOM reactions are a major sink for CH4 passing upward through the SMTZ and prevent high methane fluxes in the water column and to the atmosphere.

  16. Is transition zone index useful in assessing bladder outflow obstruction due to benign prostatic hyperplasia?: A prospective study

    Directory of Open Access Journals (Sweden)

    S L Sailo

    2006-01-01

    Full Text Available BACKGROUND: Benign prostatic enlargement (BPE is the commonest cause of bladder outlet obstruction in men above 50 years of age. Though pressure-flow study is the gold standard in establishing outlet obstruction, it is associated with definite morbidity. Several noninvasive parameters are described to diagnose outlet obstruction due to BPE and evaluate treatment efficacy. AIM: We studied the role of transitional zone index (TZI in assessing bladder outlet obstruction (BOO due to BPE. SETTING AND DESIGN: Prospective hospital-based cross-sectional diagnostic study. MATERIALS AND METHODS: Thirty-five men aged between 50 and 77 years with untreated lower urinary tract symptoms due to BPE were studied. Patients with prostate cancer, prostatitis, active UTI urethral stricture, neurovesical dysfunction and diabetes mellitus were excluded. All patients underwent a standard assessment using the American Urological Association (AUA symptom score, uroflow, pressure-flow (PF study and transrectal ultrasound (TRUS estimation of TZI. Investigators undertaking PF studies and TRUS were blinded to the investigation of others. From the PF studies, Abrams Griffith (AG number was calculated. Based on this, patients were grouped into obstructed (AG>40 and unobstructed (AG< 40 groups. STATISTICAL ANALYSIS: TZI was calculated and compared with PF studies using Mann-Whitney U test, logistic regression analysis and receiver operator characteristic curve (ROC. RESULTS: The mean age was 63.2 years (SD. The mean AUA scores and peak flow rate were 16.7 and 7.5 ml/sec, respectively. Of the 35 men, 21 were obstructed and 14 were unobstructed. TZI was not significantly different between the two groups, while the differences in age, AUA symptom score, prostate volume and TZ volume were statistically significant. Logistic regression model did not show any independent effect of TZI in predicting obstruction. ROC curve showed a poor overall accuracy in diagnosing obstruction due

  17. The Mineral Character and Geomechanical Properties of the Transitional Rocks from the Mesozoic-Neogene Contact Zone in the Bełchatów Lignite Deposit

    Directory of Open Access Journals (Sweden)

    Agnieszka Pękala

    2014-01-01

    Originality/value: Against the background of a number of published papers on the rocks accompanying lignite seams there is a lack of the "Bełchatów" mineralogical-petrographic studies of the transitional sediments in the Mesozoic-Neogene contact zone in the "Bełchatów" lignite deposit taking into account the aspect of raw materials. This paper has been produced to fill the void in this area.

  18. A Bayesian method to quantify azimuthal anisotropy model uncertainties: application to global azimuthal anisotropy in the upper mantle and transition zone

    Science.gov (United States)

    Yuan, K.; Beghein, C.

    2018-04-01

    Seismic anisotropy is a powerful tool to constrain mantle deformation, but its existence in the deep upper mantle and topmost lower mantle is still uncertain. Recent results from higher mode Rayleigh waves have, however, revealed the presence of 1 per cent azimuthal anisotropy between 300 and 800 km depth, and changes in azimuthal anisotropy across the mantle transition zone boundaries. This has important consequences for our understanding of mantle convection patterns and deformation of deep mantle material. Here, we propose a Bayesian method to model depth variations in azimuthal anisotropy and to obtain quantitative uncertainties on the fast seismic direction and anisotropy amplitude from phase velocity dispersion maps. We applied this new method to existing global fundamental and higher mode Rayleigh wave phase velocity maps to assess the likelihood of azimuthal anisotropy in the deep upper mantle and to determine whether previously detected changes in anisotropy at the transition zone boundaries are robustly constrained by those data. Our results confirm that deep upper-mantle azimuthal anisotropy is favoured and well constrained by the higher mode data employed. The fast seismic directions are in agreement with our previously published model. The data favour a model characterized, on average, by changes in azimuthal anisotropy at the top and bottom of the transition zone. However, this change in fast axes is not a global feature as there are regions of the model where the azimuthal anisotropy direction is unlikely to change across depths in the deep upper mantle. We were, however, unable to detect any clear pattern or connection with surface tectonics. Future studies will be needed to further improve the lateral resolution of this type of model at transition zone depths.

  19. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  20. The durability of mortar: consideration of interfacial transition zones to characterize and to model the physicals and chemicals mechanisms involved in mortar corrosion

    International Nuclear Information System (INIS)

    Bourdette, B.

    1994-01-01

    In the framework of a study program aiming at anticipating the lifetime of concrete containers used for radioactive waste surface storage, the aim of this work is to model the physical and chemical processes of leaching of the mortars (cement paste + sand) by low ionized water at pH=8.5. This step is indispensable before the predicting of concrete durability (cement paste + sand + gravels) in which it can exist an initial microcrack. The mortar can be described as a three-phase system: the aggregates, the transition aureoles (aggregates-cement paste interfaces) and the cement matrix. The evolution of the very particular characteristics of the transition aureoles in terms of the degradation have been studied. The study has shown that the thickness of the degraded zone in the transition aureole is identical to those of the cement matrix. It has been shown too that the diffusion coefficient in the degraded transition aureole is similar to the diffusion coefficient in the degraded cement matrix. These observations can eventually be explained by a recombination of the texture and of the structure of the transition aureole during the degradation. This reorganization could lead to a decrease of the textural and structural differences which exist between the transition aureole and the cement matrix. As it has been supposed that the characteristics of the degraded zone govern the degradation kinetics, the thickness degraded in the transition aureole is then similar to those of the cement matrix. Mortar can then be considered as a two-phase system towards the degradation: the cement paste is assimilated to a pure paste but with different characteristics due to the presence of transition aureoles. In order to model the degradation of the mortar, the model used has been developed and validated by Adenot for pure cement pastes. At 300 years, the model anticipates that the thickness of the degraded zone in the mortar is of 2.9 cm, which is lightly higher than for the pure paste

  1. Intrinsic Mechanisms of Ductile-brittle Transition for F460 Steel Welding Coarse Grained Heat Affected Zones with Different Heat Inputs

    Directory of Open Access Journals (Sweden)

    LI Jing

    2016-08-01

    Full Text Available Coarse grain heat affected zone (HAZ of F460 steel was simulated by a Gleeble 3800 thermo-mechanical simulator. The microstructure, critical event of the HAZ formed at various heat inputs (E were characterized and determined by optical microscopy (OM and scanning electronic microscopy (SEM, and cleavage fracture stress σf was also calculated by ABAQUS software. Based on above systematic analysis, the intrinsic mechanism of ductile-brittle transition for F460 steel heat affected zones with different heat inputs were revealed. The results indicate that:with the improvement of heat input, the microstructures in sequence are a minority of lath martensite and massive fine lath bainite, more lath bainite with less granular bainite, more granular bainite with less lath bainite, bulky of granular bainite; and the maximum size of the original austenite grain and bainite packet becomes bigger with the improvement of heat input. The size of bainite packet is critical event of the cleavage fracture for coarse grain heat affected zone specimens with various heat inputs by comparing the relationships among residual crack length, original austenite grain size and bainite packet size. With the decreasing of the bainitic packet, the ductile to brittle transition temperature decreases. In addition, cleavage fracture stress σf is also calculated by ABAQUS software, σf gradually decreases with the increase of the heat input, which can explain the intrinsic mechanism of ductile to brittle transition temperature Tk with the change of the heat input.

  2. Louisiana Speaks Transportation Option B Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_transit_corridors

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

  3. Louisiana Speaks Transportation Option C Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_transit_corridors

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

  4. Louisiana Speaks Transportation Option C Transit Stations, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_transit_stations

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates potential fixed-transit stations included in the Louisiana Speaks Regional Plan community growth option of compact development...

  5. Louisiana Speaks Regional Vision Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_transit_corridors

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the primary and secondary transit corridors included in the Louisiana Speaks Regional Plan Vision. This network accommodates a...

  6. 33 CFR 165.1709 - Security Zones: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG...

    Science.gov (United States)

    2010-07-01

    ... Gas Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. 165.1709 Section...: Liquefied Natural Gas Tanker Transits and Operations at Phillips Petroleum LNG Pier, Cook Inlet, AK. (a... and outbound transits through Cook Inlet, Alaska between the Phillips Petroleum LNG Pier, 60°40′43″ N...

  7. Characteristics of Conducting the Multi-Component Seismic Prospecting in the Transition Zone in Conditions of Very Shallow Water of Arctic Seas

    Directory of Open Access Journals (Sweden)

    I. A. Matveev

    2017-12-01

    Full Text Available Transition zones of transition from land to sea are the areas where it is extremely difficult to conduct geophysical works with conventional methods. In the Arctic seas of Russia, there are additional difficulties associated with the short field season, unfavorable hydrometeorological conditions, and severe restrictions imposed on the methodology and acquisition techniques by requirements of the environmental nature protection legislation. To obtain high-quality seismic data it is extremely important to select the most suitable equipment for data acquisition, optimal shooting geometry and data acquisition methodology, and the most advanced data processing and quality control software. The purpose of this article is to show developed at JSC MAGE 4-component 2D seismic technology based on use of the autonomous bottom stations. It allows conducting the seismic regional 2D survey in the transit area with registration of converted (PS waves at higher efficiency level.

  8. Three-dimensional Seismic Survey of the Continental-Ocean Transition Zone of the Northern South China Sea

    Science.gov (United States)

    Zhao, M.; Wang, Q.; Sibuet, J. C.; Sun, L.; Sun, Z.; Qiu, X.

    2017-12-01

    91428204, 41576070 and 41176053). Key words: Continental-ocean transition zone (COT); 3D refraction survey; IODP Expeditions 367/368; nature of crust.

  9. Sudden disintegration of ice in the glacial-proglacial transition zone of the largest glacier in Austria

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas; Avian, Michael; Hirschmann, Simon; Lieb, Gerhard Karl; Seier, Gernot; Sulzer, Wolfgang; Wakonigg, Herwig

    2017-04-01

    Rapid deglaciation does not only reveal a landscape which is prone to rapid geomorphic changes and sediment reworking but also the glacier ice itself might be in a state of disintegration by ice melting, pressure relief, crevasse formation, ice collapse or changes in the glacier's hydrology. In this study we considered the sudden disintegration of glacier ice in the glacial-proglacial transition zone of Pasterze Glacier. Pasterze Glacier is a typical alpine valley glacier and covers currently some 16.5 km2 making it to the largest glacier in Austria. This glacier is an important site for alpine mass tourism in Austria related to a public high alpine road and a cable car which enable access to the glacier rather easily also for unexperienced mountaineers. Spatial focus in our research is given on two particular study areas where several ice-mass movement events occurred during the 2015- and 2016-melting seasons. The first study area is a crevasse field at the lower third of the glacier tongue. This lateral crevasse field has been substantially modified during the last two melting seasons particularly because of thermo-erosional effects of a glacial stream which changed at this site from subglacial (until 2015) to glacier-lateral revealing a several tens of meters high unstable ice cliff prone to ice falls of different magnitudes. The second study area is located at the proglacial area. At Pasterze Glacier the proglacial area is widely influenced by dead-ice bodies of various dimensions making this area prone to slow to sudden geomorphic changes caused by ice mass changes. A particular ice-mass movement event took place on 20.09.2016. Within less than one hour the surface of the proglacial area changed substantially by tilting, lateral shifting, and subsidence of the ground accompanied by complete ice disintegration of once-debris covered ice. To understand acting processes at both areas of interest and to quantify mass changes we used field observations, terrain

  10. Frozen Martian lahars? Evaluation of morphology, degradation and geologic development in the Utopia-Elysium transition zone

    Science.gov (United States)

    Pedersen, G. B. M.

    2013-09-01

    Regional coverage of high-resolution data from the CTX camera has permitted new, detailed morphologic analysis of the enigmatic Utopia-Elysium flows which dominate the transition zone between Elysium volcanic province and Utopia Planitia. Based on topographic and morphologic analysis of the Galaxias region, this study supports the lahar hypothesis put forth by previous works and suggests that the center and the margins of the outflow deposits have very diverse morphologies that can be explained by varying degrees of water drainage and freezing. Regular channel and flood plain deposits are found in the central part of the outflow deposits, whereas the marginal deposits are interpreted to contain significant amount of ice because of their distinct morphological properties (smooth, lobate flow-fronts with upward convex snouts, unusual crater morphologies, raised rim fractures and localized flow fronts indicating rheomorphism). Thus, this study suggest that, unlike terrestrial lahars, lahar emplacement under Martian conditions only drain in the central parts, whereas the water in the margins of the outflow deposit (∼75% of the total outflow deposit in the Galaxias region) freezes up resulting in a double-layered deposit consisting of ice-rich core with an ice-poor surface layer. It is here furthermore suggested that continued intrusive volcanic activity was highly affected by the presence of the ice-rich lahar deposits, generating ground-ice-volcano interactions resulting in a secondary suite of morphologies. These morphologies include seventeen ridges that are interpreted to be möberg ridges (due to their NW-SE orientation, distinct ridge-crests and association with fractures and linear ridges) and depressions with nested faults interpreted to be similar to terrestrial ice-cauldrons, which form by enhanced subglacial geothermal activity including subglacial volcanic eruptions. These sub-lahar intrusions caused significant volatile loss in the ice-rich core of the

  11. Involvement of trigeminal transition zone and laminated subnucleus caudalis in masseter muscle hypersensitivity associated with tooth inflammation.

    Directory of Open Access Journals (Sweden)

    Kohei Shimizu

    Full Text Available A rat model of pulpitis/periapical periodontitis was used to study mechanisms underlying extraterritorial enhancement of masseter response associated with tooth inflammation. Periapical bone loss gradually increased and peaked at 6 weeks after complete Freund's adjuvant (CFA application to the upper molar tooth pulp (M1. On day 3, the number of Fos-immunoreactive (IR cells was significantly larger in M1 CFA rats compared with M1 vehicle (veh rats in the trigeminal subnucleus interpolaris/caudalis transition zone (Vi/Vc. The number of Fos-IR cells was significantly larger in M1 CFA and masseter (Mass capsaicin applied (M1 CFA/Mass cap rats compared with M1 veh/Mass veh rats in the contralateral Vc and Vi/Vc. The number of phosphorylated extracellular signal-regulated kinase (pERK-IR cells was significantly larger in M1 CFA/Mass cap and M1 veh/Mass cap rats compared to Mass-vehicle applied rats with M1 vehicle or CFA in the Vi/Vc. Pulpal CFA application caused significant increase in the number of Fos-IR cells in the Vi/Vc but not Vc on week 6. The number of pERK-IR cells was significantly lager in the rats with capsaicin application to the Mass compared to Mass-vehicle treated rats after pulpal CFA- or vehicle-application. However, capsaicin application to the Mass did not further affect the number of Fos-IR cells in the Vi/Vc in pulpal CFA-applied rats. The digastric electromyographic (d-EMG activity after Mass-capsaicin application was significantly increased on day 3 and lasted longer at 6 weeks after pulpal CFA application, and these increase and duration were significantly attenuated by i.t. PD98059, a MEK1 inhibitor. These findings suggest that Vi/Vc and Vc neuronal excitation is involved in the facilitation of extraterritorial hyperalgesia for Mass primed with periapical periodontitis or acute pulpal-inflammation. Furthermore, phosphorylation of ERK in the Vi/Vc and Vc play pivotal roles in masseter hyperalgesia after pulpitis or

  12. Lateral Variations of the Mantle Transition Zone Structure beneath the Southeastern Tibetan Plateau Revealed by P-wave Receiver Functions

    Science.gov (United States)

    Bai, Y.; Ai, Y.; Jiang, M.; He, Y.; Chen, Q.

    2017-12-01

    The deep structure of the southeastern Tibetan plateau is of great scientific importance to a better understanding of the India-Eurasia collision as well as the evolution of the magnificent Tibetan plateau. In this study, we collected 566 permanent and temporary seismic stations deployed in SE Tibet, with a total of 77853 high quality P-wave receiver functions been extracted by maximum entropy deconvolution method. On the basis of the Common Conversion Point (CCP) stacking technique, we mapped the topography of the 410km and 660km discontinuities (hereinafter called the `410' and the `660'), and further investigated the lateral variation of the mantle transition zone (MTZ) thickness beneath this region. The background velocity model deduced from H-κ stacking results and a previous body-wave tomographic research was applied for the correction of the crustal and upper mantle heterogeneities beneath SE Tibet for CCP stacking. Our results reveal two significantly thickened MTZ anomalies aligned nearly in the south-north direction. The magnitude of both anomalies are 30km above the global average of 250km. The southern anomaly located beneath the Dianzhong sub-block and the Indo-China block is characterized by a slightly deeper `410' and a greater-than-normal `660', while the northern anomaly beneath western Sichuan has an uplifted `410' and a depressed `660'. Combining with previous studies in the adjacent region, we suggest that slab break-off may occurred during the eastward subduction of the Burma plate, with the lower part of the cold slab penetrated into the MTZ and stagnated at the bottom of the `660' which may cause the southern anomaly in our receiver function images. The origin of the Tengchong volcano is probably connected to the upwelling of the asthenospheric material caused by the slab break-off or to the ascending of the hot and wet material triggered by the dehydration of stagnant slab in the MTZ. The anomaly in the north, on the other hand, might be

  13. Sedimentary fabrics of the macrotidal, mud-dominated, inner estuary to fluvio-tidal transition zone, Petitcodiac River estuary, New Brunswick, Canada

    Science.gov (United States)

    Shchepetkina, Alina; Gingras, Murray K.; Zonneveld, John-Paul; Pemberton, S. George

    2016-03-01

    The study provides a detailed description of mud-dominated sedimentary fabrics and their application for the rock record within the inner estuary to the fluvial zone of the Petitcodiac River estuary, New Brunswick, Canada. Sedimentological characteristics and facies distributions of the clay- and silt-rich deposits are reported. The inner estuary is characterized by thick accumulations of interbedded silt and silty clay on intertidal banks that flank the tidally influenced channel. The most common sedimentary structures observed are parallel and wavy lamination, small-scale soft-sediment deformation with microfaults, and clay and silt current ripples. The tidal channel contains sandy silt and clayey silt with planar lamination, massive and convolute bedding. The fluvio-tidal transition zone is represented by interbedded trough cross-stratified sand and gravel beds with planar laminated to massive silty mud. The riverine, non-tidal reach of the estuary is characterized by massive, planar tabular and trough cross-stratified gravel-bed deposits. The absence of bioturbation within the inner estuary to the fluvio-tidal transition zone can be explained by the following factors: low water salinities (0-5 ppt), amplified tide and current speeds, and high concentrations of flocculated material in the water body. Notably, downstream in the middle and outer estuary, bioturbation is seasonally pervasive: in those locales the sedimentary conditions are similar, but salinity is higher. In this study, the sedimentological (i.e., grain size, bedding characters, sedimentary structures) differences between the tidal estuary and the fluvial setting are substantial, and those changes occur over only a few hundred meters. This suggests that the widely used concept of an extensive fluvio-tidal transition zone and its depositional character may not be a geographically significant component of fluvial or estuary deposits, which can go unnoticed in the study of the ancient rocks.

  14. Genetic population structure of turbot ( Scophthalmus maximus L.) supports the presence of multiple hybrid zones for marine fishes in the transition zone between the Baltic Sea and the North Sea

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Nielsen, P.H.; Meldrup, Dorte

    2004-01-01

    Sea, suggesting high gene flow among populations in these areas. In contrast, there was a sharp cline in genetic differentiation going from the low saline Baltic Sea to the high saline North Sea. The data were explained best by two divergent populations connected by a hybrid zone; however......, a mechanical mixing model could not be ruled out. A significant part of the genetic variance could be ascribed to variation among years within locality. Nevertheless, the population structure was relatively stable over time, suggesting that the observed pattern of genetic differentiation is biologically...... significant. This study suggests that hybrid zones are a common phenomenon for marine fishes in the transition area between the North Sea and the Baltic Sea and highlights the importance of using interspecific comparisons for inferring population structure in high gene flow species such as most marine fishes....

  15. Louisiana Speaks Transportation Option B Transit Stations, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_transit_stations

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates potential fixed-transit stations included in the Louisiana Speaks Regional Plan community growth option of compact and dispersed...

  16. C-O-H-N fluids circulations and graphite precipitation in reactivated Hudsonian shear zones during basement uplift of the Wollaston-Mudjatik Transition Zone: Example of the Cigar Lake U deposit

    Science.gov (United States)

    Martz, Pierre; Cathelineau, Michel; Mercadier, Julien; Boiron, Marie-Christine; Jaguin, Justine; Tarantola, Alexandre; Demacon, Mickael; Gerbeaud, Olivier; Quirt, David; Doney, Amber; Ledru, Patrick

    2017-12-01

    Graphitic shear zones are spatially associated with unconformity-related uranium deposits that are located around the unconformity between the strata of the Paleo- to Mesoproterozoic Athabasca Basin (Saskatchewan, Canada) and its underlying Archean to Paleoproterozoic basement. The present study focuses on basement-hosted ductile-brittle graphitic shear zones near the Cigar Lake U deposit, one of the largest unconformity-related U deposits. The goal of the study is to decipher the pre-Athabasca Basin fluid migration history recorded within such structures and its potential role on the formation of such exceptional deposit. Dominantly C-O-H(-N) metamorphic fluids have been trapped in Fluid Inclusion Planes (FIPs) in magmatic quartz within ductile-brittle graphitic shear zones active during retrograde metamorphism associated with the formation of the Wollaston-Mudjatik Transition Zone (WMTZ) between ca. 1805 and 1720 Ma. Such fluids show a compositional evolution along the retrograde path, from a dense and pure CO2 fluid during the earliest stages, through a lower density CO2 ± CH4-N2 (± H2O) fluid and, finally, to a very low density CH4-N2 fluid. Statistical study of the orientation, distribution, proportion, and chemical characterization of the FIPs shows that: i) CO2 (δ13CCO2 around - 9‰ PDB) from decarbonation reactions and/or partial water-metamorphic graphite equilibrium initially migrated regionally and pervasively under lithostatic conditions at about 500 to 800 °C and 150 to 300 MPa. Such P-T conditions attest to a high geothermal gradient of around 60 to 90 °C/km, probably related to rapid exhumation of the basement or a large-scale heat source. ii) Later brittle reactivation of the shear zone at around 450 °C and 25-50 MPa favored circulation of CO2-CH4-N2(± H2O) fluids in equilibrium with metamorphic graphite (δ13CCO2 around - 14‰) under hydrostatic conditions and only within the shear zones. Cooling of these fluids and the water uptake linked

  17. Seismic images of the transition zone: is Hawaiian volcanism produced by a secondary plume from the top of the lower mantle?

    Science.gov (United States)

    Cao, Q.; van der Hilst, R. D.; Shim, S.; De Hoop, M. V.

    2011-12-01

    The Hawaiian hotspot is often attributed to hot material rising from depth in the mantle, but efforts to detect a thermal plume seismically have been inconclusive. Most tomographic models reveal anomalously low wavespeeds beneath Hawaii, but the depth extent of this structure is not well known. S or P data used in traveltime inversions are associated with steep rays to distant sources, which degrades depth resolution, and surface wave dispersion does not have sufficient sensitivity at the depths of interest. To investigate pertinent thermal anomalies we mapped depth variations of upper mantle discontinuities using precursors of the surface-reflected SS wave. Instead of stacking the data over geographical bins, which leads to averaging of topography and hence loss of spatial resolution, we used a generalized Radon transform (GRT) to detect and map localized elasticity contrasts in the transition zone (Cao et al., PEPI, 2010). We apply the GRT to produce 3D image volumes beneath a large area of the Pacific Ocean, including Hawaii and the Hawaii-Emperor seamount chain (Cao et al., Science, 2011). The 3D image volumes reveal laterally continuous interfaces near 410 and 660 km depths, that is, the traditional boundaries of the transition zone, but also suggest (perhaps intermittent) scatter horizons near 300-350, 520-550, and 800-1000 km depth. The upper mantle appears generally hot beneath Hawaii, but the most conspicuous topographic (and probably thermal) anomalies are found west of Hawaii. The GRT images reveal a 800 km wide uplift of the 660 discontinuity just west of Hawaii, but there is no evidence for a corresponding localized depression of the 410 discontinuity. This expression of the 410 and 660 km topographies is consistent with some existed geodynamical modeling results, in which a deep-rooted mantle plume impinging on the transition zone, creating a broad pond of hot material underneath endothermic phase change at 660 km depth, and with secondary plumes

  18. Effect of sediment composition on methane concentration and production in the transition zone of a mangrove (Sepetiba Bay, Rio de Janeiro, Brazil)

    OpenAIRE

    Marinho,CC.; Campos,EA.; Guimarães,JRD.; Esteves,FA.

    2012-01-01

    The aim of this research was to evaluate the effect of sediment composition on methane (CH4) dynamics in sediments of different areas in the transition zone between a mangrove and the sea. This research was conducted in a mangrove at Coroa Grande, on the southern coast of Rio de Janeiro. Samples were collected at three stations: (1) region colonised by Rhizophora mangle L. on the edge of the mangrove, (2) region colonised by seagrasses and (3) infra-littoral region without vegetation. Samples...

  19. Radiomic features for prostate cancer detection on MRI differ between the transition and peripheral zones: Preliminary findings from a multi-institutional study.

    Science.gov (United States)

    Ginsburg, Shoshana B; Algohary, Ahmad; Pahwa, Shivani; Gulani, Vikas; Ponsky, Lee; Aronen, Hannu J; Boström, Peter J; Böhm, Maret; Haynes, Anne-Maree; Brenner, Phillip; Delprado, Warick; Thompson, James; Pulbrock, Marley; Taimen, Pekka; Villani, Robert; Stricker, Phillip; Rastinehad, Ardeshir R; Jambor, Ivan; Madabhushi, Anant

    2017-07-01

    To evaluate in a multi-institutional study whether radiomic features useful for prostate cancer (PCa) detection from 3 Tesla (T) multi-parametric MRI (mpMRI) in the transition zone (TZ) differ from those in the peripheral zone (PZ). 3T mpMRI, including T2-weighted (T2w), apparent diffusion coefficient (ADC) maps, and dynamic contrast-enhanced MRI (DCE-MRI), were retrospectively obtained from 80 patients at three institutions. This study was approved by the institutional review board of each participating institution. First-order statistical, co-occurrence, and wavelet features were extracted from T2w MRI and ADC maps, and contrast kinetic features were extracted from DCE-MRI. Feature selection was performed to identify 10 features for PCa detection in the TZ and PZ, respectively. Two logistic regression classifiers used these features to detect PCa and were evaluated by area under the receiver-operating characteristic curve (AUC). Classifier performance was compared with a zone-ignorant classifier. Radiomic features that were identified as useful for PCa detection differed between TZ and PZ. When classification was performed on a per-voxel basis, a PZ-specific classifier detected PZ tumors on an independent test set with significantly higher accuracy (AUC = 0.61-0.71) than a zone-ignorant classifier trained to detect cancer throughout the entire prostate (P  0.14) were obtained for all institutions. A zone-aware classifier significantly improves the accuracy of cancer detection in the PZ. 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:184-193. © 2016 International Society for Magnetic Resonance in Medicine.

  20. Ringwoodite growth rates from olivine with ~75 ppmw H2O: Metastable olivine must be nearly anhydrous to exist in the mantle transition zone

    Energy Technology Data Exchange (ETDEWEB)

    Du Frane, Wyatt L. [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Atmospheric, Earth and Energy Division; Sharp, Thomas G. [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration; Mosenfelder, Jed L. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Geological and Planetary Sciences; Leinenweber, Kurt [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration

    2013-04-15

    It has been previously demonstrated that as little as 300 ppmw H2O increases wadsleyite and ringwoodite growth rates to magnitudes that are inconsistent with the metastable olivine hypothesis. To further test this hypothesis, we present new ringwoodite growth rate measurements from olivine with ~75 ppmw H2O at 18 GPa and 700, 900, and 1100 °C. These growth rates are nearly identical to those from olivine with ~300 ppmw H2O, and significantly higher than those from nominally anhydrous olivine. We infer that transformation of olivine with 75-300 ppmw H2O is primarily enhanced by hydrolytic weakening of reaction rims, which reduces the elastic strain-energy barrier to growth. We present a new method for fitting nonlinear nominally anhydrous data, to demonstrate that reduction of growth rates by elastic strain energy is an additional requirement for metastable olivine. In conclusion, based on previous thermokinetic modeling, these enhanced growth rates are inconsistent with the persistence of metastable olivine wedges into the mantle transition zone. Metastable persistence of olivine into the mantle transition-zone would therefore require < 75 ppmw H2O.

  1. Laparoscopy-assisted versus transabdominal reoperation in Hirschprung's disease for residual aganglionosis and transition zone pathology after transanal pull-through.

    Science.gov (United States)

    Xia, Xue; Li, Ning; Wei, Jia; Zhang, Wen; Yu, Donghai; Zhu, Tianqi; Feng, Jiexiong

    2016-04-01

    This study aims to describe laparoscopic reoperation (LSR) and compare its outcomes with transabdominal reoperation (TAR) for treating Hirschsprung's disease (HD). Eighteen patients with HD underwent reoperation for recurring constipation due to residual aganglionosis and transition zone pathology after an initial transanal procedure (LSR, n=10; TAR, n=8). Preoperative, operative and postoperative data were collected through patient follow-ups ranging from 13 to 75months to compare operative characteristics and postoperative outcomes between the two groups. Ten patients underwent laparoscopic reoperation in our institution without major complications. On average, blood loss was significantly lower in the LSR group (mean±standard deviation, 83±32.7mL) than in the TAR group (185±69mL) (P=0.001). The LSR group had a shorter hospitalization time (12±2days) than the TAR group (15±2.1days) (P=0.02). There was no statistically significant difference in incidence of postoperative complications between the two groups. LSR is safe and technically feasible in HD for recurring constipation due to residual aganglionosis and transition zone pathology, when initial transanal procedure fails. Although RA and TZP can be cured by reoperation, great efforts should be made to diminish the necessity of reoperation. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. The role of strain hardening in the transition from dislocation-mediated to frictional deformation of marbles within the Karakoram Fault Zone, NW India

    Science.gov (United States)

    Wallis, David; Lloyd, Geoffrey E.; Hansen, Lars N.

    2018-02-01

    The onset of frictional failure and potentially seismogenic deformation in carbonate rocks undergoing exhumation within fault zones depends on hardening processes that reduce the efficiency of aseismic dislocation-mediated deformation as temperature decreases. However, few techniques are available for quantitative analysis of dislocation slip system activity and hardening in natural tectonites. Electron backscatter diffraction maps of crystal orientations offer one such approach via determination of Schmid factors, if the palaeostress conditions can be inferred and the critical resolved shear stresses of slip systems are constrained. We analyse calcite marbles deformed in simple shear within the Karakoram Fault Zone, NW India, to quantify changes in slip system activity as the rocks cooled during exhumation. Microstructural evidence demonstrates that between ∼300 °C and 200-250 °C the dominant deformation mechanisms transitioned from dislocation-mediated flow to twinning and frictional failure. However, Schmid factor analysis, considering critical resolved shear stresses for yield of undeformed single crystals, indicates that the fraction of grains with sufficient resolved shear stress for glide apparently increased with decreasing temperature. Misorientation analysis and previous experimental data indicate that strain-dependent work hardening is responsible for this apparent inconsistency and promoted the transition from dislocation-mediated flow to frictional, and potentially seismogenic, deformation.

  3. The role of sexual vs. asexual recruitment of Artemisia wudanica in transition zone habitats between inter-dune lowlands and active dunes in Inner Mongolia, China

    Science.gov (United States)

    Wang, Yongcui; Alberto, Busso Carlos; Jiang, Deming; Ala, Musa; Li, Xuehua; Zhou, Quanlai; Lin, Jixiang; Ren, Guohua; Jia, Lian

    2016-04-01

    Artemisia wudanica is an endemic, perennial, pioneering psammophyte species in the sand dune ecosystems of western Horqin Sand Land in northern China. However, no studies have addressed how sexual and asexual reproduction modes of A. wudanica perform at the transitional zones between active dune inter-dune lowlands and active dunes. In early spring, quadrats were randomly set up in the study area to monitor surviving seedling and/or ramet density and frequency coming from sexual/asexual reproduction of A. wudanica. Iron sticks were inserted near each quadrat to determine wind erosion intensity (WE). Additionally, soil samples were collected nearby each quadrat to test for soil moisture (SM), organic matter (OM) and pH. Surviving seedlings of A. wudanica showed an inverse response in comparison with ramets to SM, OM and WE. Soil moisture showed the most positive effect, and WE the negative effect, on surviving, sexual reproduction seedlings. Contrarily, WE had the most positive effect, and SM the negative effect, on asexual reproduction ramets. This suggests that increases in SM and decreases in WE should benefit recruitment of A. wudanica seedlings. On the contrary, ramets coming from asexual reproduction showed a different response to environmental factors in transition zone habitats. While SM was not a key constraint for the survival of seedlings, they showed a better, positive response to wind erosion environments. Overall, various study environmental parameters could be improved to foster A. wudanica invasion and settlement in the plant community through different reproductive modes, thereby promoting vegetation restoration and rehabilitation.

  4. UV filters, ethylhexyl methoxycinnamate, octocrylene and ethylhexyl dimethyl PABA from untreated wastewater in sediment from eastern Mediterranean river transition and coastal zones.

    Science.gov (United States)

    Amine, Helmieh; Gomez, Elena; Halwani, Jalal; Casellas, Claude; Fenet, Hélène

    2012-11-01

    UVF may occur in the aquatic environment through two principal sources: direct inputs from recreational activities and indirect wastewater- and river-borne inputs. The aim of this study was to obtain a first overview of levels of three UVF (EHMC, OC and OD-PABA) in coastal areas subjected to river inputs, untreated wastewater discharges and dumpsite leachates. We selected three eastern Mediterranean rivers that have been impacted for decades by untreated wastewater release and collected sediment in the coastal zone during the hot and humid seasons. Western Mediterranean sites receiving treated wastewaters were analyzed for comparison. The results gave an overview of sediment contamination under these two contrasted situations representative of Mediterranean coastal areas without bathing activities. The analysis of the three UVF revealed the ubiquity and high point source contamination by EHMC and OC in transition and coastal zones, with levels as high as 128 ng g(-1)d.w. OD-PABA was also frequently detected, but at lower concentrations (zones. Copyright © 2012. Published by Elsevier Ltd.

  5. Modulation of flagellum attachment zone protein FLAM3 and regulation of the cell shape in Trypanosoma brucei life cycle transitions

    Czech Academy of Sciences Publication Activity Database

    Sunter, J.C.; Benz, C.; Andre, L.; Whipple, S.; McKean, P.G.; Gull, K.; Ginger, M. L.; Lukeš, Julius

    2015-01-01

    Roč. 128, č. 16 (2015), s. 3117-3130 ISSN 0021-9533 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA MŠk LH12104 EU Projects: European Commission(XE) 316304 Institutional support: RVO:60077344 Keywords : Trypanosomes * Morphogenesis * Flagellum attachment zone Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.706, year: 2015

  6. ANALYSIS OF DEFORMED STATE STRUCTURES OF THE KYIV METRO RUNNING TUNNELS ON A TRANSITION ZONE FROM SPONDYLOV’S CLAY TO BUCHATSKIY SANDS

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2014-07-01

    Full Text Available Purpose. In the section of changes geotechnical conditions of spondylov’s clay to buchatskiy sands may have significant structural deformation of running tunnels. It is necessary to identify the cause of deformities develop ways to minimize and based modeling and calculations to prove the effectiveness of measures to reduce deformation.Methodology. To solve the analysis problem of the stress-strain state (SSS of the system «structure array» it was conducted the numerical simulation using the finite element method (FEM. On the basis of the obtained results the graphs were constructed and the dependencies were determined. Findings. The presence of weak water-saturated soils in tray of the tunnel on an area of transition from spondylov’s clay to buchatskiy sand causes significant increasing in strain construction of tunnels and general vibration liquefaction in soil basis. Also change the physical and mechanical characteristics of soils within the frames of tunnels influences on the level of strain state of most frames. Improved strain state settings of tunnels in areas of change soil characteristics of the array (especially at the bottom of casing can be achieved by chemical consolidation of weak soils. Composition of solutions for fixing the weak soils should be determined based on the study of grain size, porosity, and other parameters of physical and mechanical and physical and chemical characteristics of soils.Originality.The basic cause significant strain on transition zone from spondylov’s clay to buchatskiy sands is found, that is explained by saturated phenomenon vibration liquefaction basis under the tunnel.Practical value.The approaches to reduce the strain in the construction of running tunnels in the transition zone from spondylov’s clay to buchatskiy sands are developed, as well as in the area ofthe station «Glybochytska»the Kyiv Metro.

  7. Diagnostic sedimentary structures of the fluvial-tidal transition zone – Evidence from deposits of the Rhine and Meuse

    NARCIS (Netherlands)

    Berg, J.H. van den; Boersma, J.R.; Gelder, A. van

    2007-01-01

    n mesotidal settings the transition of a coastal plain estuary to the river is marked by the change of a multiple ebb and flood channel configurationto a single channel system. At high river discharge fluvial processes operate, whereas in periods of low discharge the flow is complicated by a

  8. Effect of sediment composition on methane concentration and production in the transition zone of a mangrove (Sepetiba Bay, Rio de Janeiro, Brazil).

    Science.gov (United States)

    Marinho, C C; Campos, E A; Guimarães, J R D; Esteves, F A

    2012-08-01

    The aim of this research was to evaluate the effect of sediment composition on methane (CH4) dynamics in sediments of different areas in the transition zone between a mangrove and the sea. This research was conducted in a mangrove at Coroa Grande, on the southern coast of Rio de Janeiro. Samples were collected at three stations: (1) region colonised by Rhizophora mangle L. on the edge of the mangrove, (2) region colonised by seagrasses and (3) infra-littoral region without vegetation. Samples were collected from the surface layer of the sediment to determine the concentrations of nutrients (C, N and P) and CH4 concentration and production. We observed that concentrations of CH4 and carbon (C) were significantly higher (p Mangrove Coroa Grande is a function of available OM suggesting a possible inhibition of methanotrophy by intense oxygen consumption in the soil surface covered by detritus of Rhizophora mangle vegetation.

  9. Diachronism in the late Neoproterozoic-Cambrian arc-rift transition of North Gondwana: A comparison of Morocco and the Iberian Ossa-Morena Zone

    Science.gov (United States)

    Álvaro, J. Javier; Bellido, Félix; Gasquet, Dominique; Pereira, M. Francisco; Quesada, Cecilio; Sánchez-García, Teresa

    2014-10-01

    In the northwestern border of the West African craton (North Gondwana), a transition from late Neoproterozoic subduction/collision to Cambrian rift processes was recorded in the Anti-Atlas (Morocco) and in the Ossa-Morena Zone (Iberia). Cambrian rifting affected both Pan-African and Cadomian basements in a stepwise and diachronous way. Subsequently, both areas evolved into a syn-rift margin episodically punctuated by uplift and tilting that precluded Furongian sedimentation. A comparison of sedimentary, volcanic and geodynamic evolution is made in the late Neoproterozoic (Pan-African and Cadomian) belts and Cambrian rifts trying to solve the apparent diachronous (SW-NE-trending) propagation of an early Palaeozoic rifting regime that finally led to the opening of the Rheic Ocean.

  10. The first report of a microdiverse anammox bacteria community in waters of Colombian Pacific, a transition area between prominent oxygen minimum zones of the eastern tropical Pacific.

    Science.gov (United States)

    Castro-González, M; Molina, V; Rodríguez-Rubio, E; Ulloa, O

    2014-12-01

    Anaerobic ammonium oxidizers contribute to the removal of fixed nitrogen in oxygen-deficient marine ecosystems such as oxygen minimum zones (OMZ). Here we surveyed for the first time the occurrence and diversity of anammox bacteria in the Colombian Pacific, a transition area between the prominent South and North Pacific OMZs. Anammox bacteria were detected in the coastal and oceanic areas of the Colombian Pacific in low oxygen (Chile and Arabian Sea) within Candidatus ‘Scalindua spp’. Moreover, some anammox bacteria OTUs shared a low similarity with environmental phylotypes (86–94%). Our results indicated that a microdiverse anammox community inhabits the Colombian Pacific, generating new questions about the ecological and biogeochemical differences influencing its community structure.

  11. [Carbon balance of household production system in the transition zone from the Loess Plateau to the Qinghai-Tibet Plateau, China].

    Science.gov (United States)

    Wu, Chao Chao; Gao, Xiao Ye; Hou, Fu Jiang

    2017-10-01

    The transition zone from the Loess Plateau to the Qinghai-Tibet Plateau is one of the regions with most dramatic changes in agricultural production mode and most sensitive response to the carbon balance effect. This paper analyzed the carbon balance of the agriculture system along the altitude gradient in Tongwei, Weiyuan and Xiahe counties. The results showed that with the increase of altitude, the carbon emission, carbon fixation and carbon sink capacity of crops per unit area decreased accordingly, while the average carbon emission, carbon fixation and carbon source capacity of each household in livestock system increased. The integrated crop-livestock production system changed from carbon sink to carbon source. The average carbon emission of each household rose with altitude, but the carbon fixation was the opposite. The change of percentage ofhousehold in the transition zone from the Loess Plateau to the Qinghai-Tibet Plateau with carbon balance could be fitted with Logistic equation. In the crop system of Tongwei, Weiyuan and Xiahe with the altitude increase, carbon emission at the inflection point where the household percentage accounted for 50.0% was 1491, 857 and 376 kg CE·household -1 , and carbon fixation was 6187, 3872 and 778 kg CE·household -1 , respectively. For the livestock system, carbon emission was 2218, 3725 and 49511 kg CE·household -1 , and carbon fixation was 138, 230 and 2706 kg CE·household -1 , respectively. For the integrated crop-livestock system, carbon emission was 3615, 4583 and 49918 kg CE·household -1 , and carbon fixation was 6289, 4113 and 3819 kg CE·household -1 , respectively, which could be the key point for the regulation of regional carbon balance.

  12. Vema-TRANSIT - An interdisciplinary study on the bathymetry of the Vema-Fracture Zone and Puerto Rico Trench as well as abyssal Atlantic biodiversity

    Science.gov (United States)

    Riehl, Torben; Kaiser, Stefanie; Brandt, Angelika

    2018-02-01

    The seafloor below 3500 m remains largely unexplored. The paucity of knowledge of abyssal and hadal environments encompasses a wide spectrum of geological and biological patterns and processes as well as their interactions. Historically most marine research has been conducted in the North Atlantic. However, the high proportion of undescribed taxa frequently discovered at greater depth there underline the need to fill in these knowledge gaps. The Vema-TRANSIT campaign in northern winter 2014-2015 surveyed and sampled along almost the entire extent of one of the major offsets of the Mid-Atlantic Ridge (MAR), the Vema Fracture Zone (VFZ), as well as the deepest trench in the Atlantic, the Puerto Rico Trench (PRT). The discoveries that were made include new data on deep-sea habitats showing geologically complex features across all crust ages from 110 Ma until present. Moreover, some new species and genera of the abyssal and hadal benthos were described herein. Not only the taxa themselves, but also their distributions and genetic structure were elucidated. In this context, significant differences in abundances, community composition, and species distribution were detected that were affected by the MAR as well as by the depth transition between hadal PRT and the adjacent abyss. Despite significant differences between eastern and western communities, the MAR does not represent an absolute barrier. Instead, the VFZ, and especially the VTF may serve as a connecting feature between east and west and this may be exemplary for fracture zones across the whole Atlantic. Nevertheless, the MAR as well as the 3000-m-depth gradient between abyss and hadal appear to restrict gene flow for poor dispersers and thus contribute to speciation processes in the deep sea.

  13. Assessing the hydrological response from an ensemble of CMIP5 climate projections in the transition zone of the Atlantic region (Bay of Biscay)

    Science.gov (United States)

    Meaurio, Maite; Zabaleta, Ane; Boithias, Laurie; Epelde, Ane Miren; Sauvage, Sabine; Sánchez-Pérez, Jose-Miguel; Srinivasan, Raghavan; Antiguedad, Iñaki

    2017-05-01

    The climate changes projected for the 21st century will have consequences on the hydrological response of catchments. These changes, and their consequences, are most uncertain in the transition zones. The study area, in the Bay of Biscay, is located in the transition zone of the European Atlantic region, where hydrological impact of climate change was scarcely studied. In order to address this scarcity, the hydrological impacts of climate change on river discharge were assessed. To do so, a hydrological modelling was carried out considering 16 climate scenarios that include 5 General Circulation Models (GCM) from the 5th report of the Coupled Model Intercomparison Project (CMIP5), 2 statistical downscaling methods and 2 Representative Concentration Pathways. Projections for future discharge (2011-2100) were divided into three 30-year horizons (2030s, 2060s and 2090s) and a comparison was made between these time horizons and the baseline (1961-2000). The results show that the downscaling method used resulted in a higher source of uncertainty than GCM itself. In addition, the uncertainties inherent to the methods used at all the levels do not affect the results equally along the year. In spite of those uncertainties, general trends for the 2090s predict seasonal discharge decreases by around -17% in autumn, -16% in spring, -11% in winter and -7% in summer. These results are in line with those predicted for the Atlantic region (France and the Iberian Peninsula). Trends for extreme flows were also analysed: the most significant show an increase in the duration (days) of low flows. From an environmental point of view, and considering the need to meet the objectives established by the Water Framework Directive (WFD), this will be a major challenge for the future planning on water management.

  14. Impacts of extensive driftnet fishery and late 1990s climate regime shift on dominant epipelagic nekton in the Transition Region and Subtropical Frontal Zone: Implications for fishery management

    Science.gov (United States)

    Ichii, T.; Nishikawa, H.; Igarashi, H.; Okamura, H.; Mahapatra, K.; Sakai, M.; Wakabayashi, T.; Inagake, D.; Okada, Y.

    2017-01-01

    We investigated the impacts of extensive anthropogenic (high seas driftnet squid fishery) and natural (late 1990s major climate regime shift) events on dominant epipelagic fish, squid, and shark in the central North Pacific Transition Region based on a driftnet survey covering the years 1979-2006. Fishing was conducted by Japan, Korea and Taiwan to target neon flying squid in the period 1979-1992, resulting in a decline in stocks of the target species and non-target species (Pacific pomfret and juvenile blue shark), which were by-catch of this fishery. The catch was found to be at the maximum sustainable yield (MSY) level for neon flying squid, the underfished level for juvenile blue shark, but the overfished level for Pacific pomfret. The MSY of Pacific pomfret indicated that this species is more susceptible to exploitation than previously considered. In response to the late 1990s regime shift, neon flying squid and Pacific saury showed low stock levels in 1999-2002 and 1998-2002, respectively, as a result of reduced productivity in their nursery grounds (the Subtropical Frontal Zone and Kuroshio Extension Bifurcation Region, respectively). On the other hand, Pacific pomfret showed no decreasing trend in stock during the low- and intermediate-productivity regimes because of the high productivity of their main spawning/nursery ground (Transition Zone Chlorophyll Front), which was independent of the regime shifts. Thus, squid and saury appear to be more susceptible to the regime shift than pomfret. We discuss the implications for stock management of the species-specific responses to the fishery and the regime shift.

  15. Magnetotelluric Imaging of Lower Crustal Melt and Lithospheric Hydration in the Rocky Mountain Front Transition Zone, Colorado, USA

    Science.gov (United States)

    Feucht, D. W.; Sheehan, A. F.; Bedrosian, P. A.

    2017-12-01

    We present an electrical resistivity model of the crust and upper mantle from two-dimensional (2-D) anisotropic inversion of magnetotelluric data collected along a 450 km transect of the Rio Grande rift, southern Rocky Mountains, and High Plains in Colorado, USA. Our model provides a window into the modern-day lithosphere beneath the Rocky Mountain Front to depths in excess of 150 km. Two key features of the 2-D resistivity model are (1) a broad zone ( 200 km wide) of enhanced electrical conductivity (minerals, with maximum hydration occurring beneath the Rocky Mountain Front. This lithospheric "hydration front" has implications for the tectonic evolution of the continental interior and the mechanisms by which water infiltrates the lithosphere.

  16. Sulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan Beaufort Sea continental margin sediments: Implications for deep sulfur cycling

    Science.gov (United States)

    Treude, Tina; Krause, Stefan; Maltby, Johanna; Dale, Andrew W.; Coffin, Richard; Hamdan, Leila J.

    2014-11-01

    Two ∼6 m long sediment cores were collected along the ∼300 m isobath on the Alaskan Beaufort Sea continental margin. Both cores showed distinct sulfate-methane transition zones (SMTZ) at 105 and 120 cm below seafloor (cmbsf). Sulfate was not completely depleted below the SMTZ but remained between 30 and 500 μM. Sulfate reduction and anaerobic oxidation of methane (AOM) determined by radiotracer incubations were active throughout the methanogenic zone. Although a mass balance could not explain the source of sulfate below the SMTZ, geochemical profiles and correlation network analyses of biotic and abiotic data suggest a cryptic sulfur cycle involving iron, manganese and barite. Inhibition experiments with molybdate and 2-bromoethanesulfonate (BES) indicated decoupling of sulfate reduction and AOM and competition between sulfate reducers and methanogens for substrates. While correlation network analyses predicted coupling of AOM to iron reduction, the addition of manganese or iron did not stimulate AOM. Since none of the classical archaeal anaerobic methanotrophs (ANME) were abundant, the involvement of unknown or unconventional phylotypes in AOM is conceivable. The resistance of AOM activity to inhibitors implies deviation from conventional enzymatic pathways. This work suggests that the classical redox cascade of electron acceptor utilization based on Gibbs energy yields does not always hold in diffusion-dominated systems, and instead biotic processes may be more strongly coupled to mineralogy.

  17. Magnetic Data Interpretation for the Source-Edge Locations in Parts of the Tectonically Active Transition Zone of the Narmada-Son Lineament in Central India

    Science.gov (United States)

    Ghosh, G. K.

    2016-02-01

    The study has been carried out in the transition zone of the Narmada-Son lineament (NSL) which is seismically active with various geological complexities, upwarp movement of the mantle material into the crust through fault, fractures lamination and upwelling. NSL is one of the most prominent lineaments in central India after the Himalaya in the Indian geology. The area of investigation extends from longitude 80.25°E to 81.50°E and latitude 23.50°N to 24.37°N in the central part of the Indian continent. Different types of subsurface geological formations viz. alluvial, Gondwana, Deccan traps, Vindhyan, Mahakoshal, Granite and Gneisses groups exist in this area with varying geological ages. In this study area tectonic movement and crustal variation have been taken place during the past time and which might be reason for the variation of magnetic field. Magnetic anomaly suggests that the area has been highly disturbed which causes the Narmada-Son lineament trending in the ENE-WSW direction. Magnetic anomaly variation has been taken place due to the lithological variations subject to the changes in the geological contacts like thrusts and faults in this area. Shallow and deeper sources have been distinguished using frequency domain analysis by applying different filters. To enhance the magnetic data, various types of derivatives to identify the source-edge locations of the causative source bodies. The present study carried out the interpretation using total horizontal derivative, tilt angle derivative, horizontal tilt angle derivative and Cos (θ) derivative map to get source-edge locations. The results derived from various derivatives of magnetic data have been compared with the basement depth solutions calculated from 3D Euler deconvolution. It is suggested that total horizontal derivative, tilt angle derivative and Cos (θ) derivative are the most useful tools for identifying the multiple source edge locations of the causative bodies in this tectonically active

  18. Structural, physiognomic and above-ground biomass variation in savanna–forest transition zones on three continents – how different are co-occurring savanna and forest formations?

    Directory of Open Access Journals (Sweden)

    E. M. Veenendaal

    2015-05-01

    Full Text Available Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna–forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna–forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three

  19. Compressive strength and interfacial transition zone of sugar cane bagasse ash concrete: A comparison to the established pozzolans

    Science.gov (United States)

    Hussein, Asma Abd Elhameed; Shafiq, Nasir; Nuruddin, Muhd Fadhil

    2015-05-01

    Agricultural and industrial by-products are commonly used in concrete production as cement replacement materials (CRMs) or as admixtures to enhance both fresh and hardened properties of concrete as well as to save the environment from the negative effects caused by their disposal. Sugar Cane Bagasse Ash (SCBA) is one of the promising CRMs, it is used as a partial replacement of cement for producing concrete; properties of such concrete depend on the chemical composition, fineness, and burning temperature of SCBA. Approximately 1500 Million tons of sugarcane are annually produced over all the world which leave about 40-45% bagasse after juice crushing for sugar industry giving an average annual production of about 600 Million tons of bagasse as a waste material. This paper presents some findings on the effect of SCBA on workability, compressive strength and microstructure of interfacial zone of concrete and its performance is compared to some of the established CRMs namely Densified Silica Fume, Fly Ash and Microwave Incinerated Rice Husk Ash.

  20. Unraveling the channel–lobe transition zone with high-resolution AUV bathymetry: Navy Fan, offshore Baja California, Mexico

    Science.gov (United States)

    Carvajal, Cristian; Paull, Charles K.; Caress, David W.; Fildani, Andrea; Lundsten, Eve M.; Anderson, Krystle; Maier, Katherine L.; McGann, Mary; Gwiazda, Roberto; Herguera, Juan Carlos

    2017-01-01

    Ultra-high-resolution (1 m * 1 m * 0.25 m) bathymetry was acquired with an autonomous underwater vehicle (AUV) over a sector of the Navy Fan offshore Baja California. The survey specifically targeted an area where the former interpretation of the fan showed a channel–lobe transition; however, the lobe and the transition were not recognized. Instead, the newly acquired bathymetry shows that the previously identified channel continues basinward changing its overall morphology and stratigraphic architecture, becoming gradually but significantly wider (650–1000 m) and of lower relief (3–4 m). Cores from the channel thalweg recovered mud-poor (< 5%) well-sorted sands, interpreted as deposited by fully turbulent flows. The cores also show several mud-rich (9–18%) poorly sorted sands, probably indicating deposition from more cohesive flows.The high-resolution bathymetry shows large sectors of the seafloor sculpted by elaborate bedforms and scours. The overbank area north of the channel exhibits the most numerous and prominent scours, interpreted to have been largely generated by flow stripping at a bend in the channel. Along high-gradient sectors (more than approximately 1¯) of this area, the scours are largest and deepest. Some of these scours show an erosional headwall and a distal upflow-dipping depositional bulge, forming repetitive bedforms interpreted as erosional cyclic steps associated with locked-in-place trains of hydraulic jumps. The scours seem to coalesce to form an incipient channel, which would likely drive the avulsion of the main channel. Further basinward, average gradients decrease (< 0.6¯ ) and scours become smaller and less deep suggesting a gradient control on erosion. The southern channel margin and adjacent overbank area exhibit a trend of scours that are elongated transverse to flow, that successively repeat themselves basinwards, and that at times merge with sediment waves. Probably these scours are genetically linked to sediment waves

  1. Diagnosis of lesions of the acetabular labrum, of the labral-chondral transition zone, and of the cartilage in femoroacetabular impingement: Correlation between direct magnetic resonance arthrography and hip arthroscopy.

    Science.gov (United States)

    Crespo Rodríguez, A M; de Lucas Villarrubia, J C; Pastrana Ledesma, M A; Millán Santos, I; Padrón, M

    2015-01-01

    To determine the sensitivity and accuracy of direct MR arthrography in the diagnosis of intra-articular lesions associated with femoroacetabular impingement. We used direct MR arthrography to study 51 patients with femoroacetabular impingement who underwent arthroscopic hip surgery. Surgery demonstrated 37 labral tears, 44 lesions in the labral-chondral transitional zone, and 40 lesions of the articular cartilage. We correlated the findings at preoperative direct MR arthrography with those of hip arthroscopy and calculated the sensitivity, specificity, positive predictive value, negative predictive value, and validity index for direct MR arthrography. The sensitivity and specificity of MR arthrography were 94.5% and 100%, respectively, for diagnosing labral tears, 100% and 87.5%, respectively, for diagnosing lesions of the labral-chondral transition zone, and 92.5% and 54.5%, respectively, for diagnosing lesions of the articular cartilage. The negative predictive value of MR arthrography for lesions of the labral-chondral transitional zone was 100%. MR arthrography accurately defined extensive lesions of the cartilage and the secondary osseous changes (the main factor in poor prognosis), although its diagnostic performance was not so good in small chondral lesions. In patients with femoroacetabular impingement, direct MR arthrography can adequately detect and characterize lesions of the acetabular labrum and of the labral-chondral transitional zone as well as extensive lesions of the articular cartilage and secondary osseous changes. Copyright © 2013 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  2. A deterministic and stochastic velocity model for the Salton Trough/Basin and Range transition zone and constraints on magmatism during rifting

    Science.gov (United States)

    Larkin, Steven P.; Levander, Alan; Okaya, David; Goff, John A.

    1996-12-01

    As a high resolution addition to the 1992 Pacific to Arizona Crustal Experiment (PACE), a 45-km-long deep crustal seismic reflection profile was acquired across the Chocolate Mountains in southeastern California to illuminate crustal structure in the transition between the Salton Trough and the Basin and Range province. The complex seismic data are analyzed for both large-scale (deterministic) and fine-scale (stochastic) crustal features. A low-fold near-offset common-midpoint (CMP) stacked section shows the northeastward lateral extent of a high-velocity lower crustal body which is centered beneath the Salton Trough. Off-end shots record a high-amplitude diffraction from the point where the high velocity lower crust pinches out at the Moho. Above the high-velocity lower crust, moderate-amplitude reflections occur at midcrustal levels. These reflections display the coherency and frequency characteristics of reflections backscattered from a heterogeneous velocity field, which we model as horizontal intrusions with a von Kármán (fractal) distribution. The effects of upper crustal scattering are included by combining the mapped surface geology and laboratory measurements of exposed rocks within the Chocolate Mountains to reproduce the upper crustal velocity heterogeneity in our crustal velocity model. Viscoelastic finite difference simulations indicate that the volume of mafic material within the reflective zone necessary to produce the observed backscatter is about 5%. The presence of wavelength-scale heterogeneity within the near-surface, upper, and middle crust also produces a 0.5-s-thick zone of discontinuous reflections from a crust-mantle interface which is actually a first-order discontinuity.

  3. Erosion Potential of a Burn Site in the Mojave-Great Basin Transition Zone: Interim Summary of One Year of Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Etyemezian, V.; Shafer, D.; Miller, J.; Kavouras, I.; Campbell, S.; DuBois, D.; King, J.; Nikolich, G.; Zitzer, S.

    2010-05-18

    A historic return interval of 100 years for large fires in deserts in the Southwest U.S. is being replaced by one where fires may reoccur as frequently as every 20 to 30 years. This increase in fires has implications for management of Soil Sub-Project Corrective Action Units (CAUs) for which the Department of Energy, National Nuclear Security Administration Nevada Site office (NNSA/NSO) has responsibility. A series of studies has been initiated at uncontaminated analog sites to better understand the possible impacts of erosion and transport by wind and water should contaminated soil sites burn over to understand technical and perceived risk they might pose to site workers and public receptors in communities around the NTS, TTR, and NTTR; and to develop recommendations for stabilization and restoration after a fire. The first of these studies was undertaken at the Jacob fire, a lightning-caused fire approximately 12 kilometers north of Hiko, Nevada, that burned approximately 200 ha between August 6-8, 2008, and is representative of a transition zone on the NTS between the Mojave and Great Basin Deserts, where the largest number of Soil Sub-Project CAUs/CASs are located.

  4. Rapid change of chromomeric and pairing patterns of polytene chromosome tips in D. melanogaster: migration of polytene-nonpolytene transition zone?

    Science.gov (United States)

    Roberts, P A

    1979-07-01

    The high variability of chromomeric patterns in near-terminal regions of polytene chromosome arms has been explored in a number of races, strains and hybrids of Drosophila melanogaster. Traditional explanations for tip differences between strains (differential compaction of chromatin, somatic or germinal deletion) are examined and, in the light of the reported observations, rejected. The range of polytene tip variability and rates of change in wild races are greater than has been supposed: strains formerly considered to be terminally deleted appear to gain terminal bands; others, formerly considered normal, appear to have lost them. Strains with high cell-to-cell tip variability are also described. Cell-to-cell variations, as well as much of the observed rapid changes in tip appearance, are probably due to heritable differences in the location of an abrupt transition zone between polytene and nonpolytene chromatin. A quantitative relationship between the amount of certain subterminal bands present and the frequency of tip association of nonhomologous chromosomes is shown and its possible significance for chromosome is shown and its possible for chromosome pairing discussed.

  5. Optical measurements in the North Sea-Baltic Sea transition zone. I. On the origin of the deep water in the Kattegat

    Science.gov (United States)

    Højerslev, N. K.; Holt, N.; Aarup, T.

    1996-08-01

    In the North Sea-Baltic Sea region, several studies have shown that yellow substance can be treated as a quasi-conservative parameter that is negatively correlated with salinity. A review of more than 5000 historic and recently gathered yellow substance absorption and salinity measurements from the transition zone between the North Sea and the Baltic Sea have been analyzed for the purpose of water mass identification. Salinity-yellow substance scatter plots show that three water masses can be identified in the area: (1) North Sea water (high salinity, low yellow substance content); (2) Baltic Sea water (low salinity, intermediate-high yellow substance content); and (3) German Bight/Southern North Sea water (intermediate-high salinity, high yellow substance content). Based on the volume flow estimates used in a two-layer box-model of the Kattegat (Jørgensen, Continental Shelf Research, 12, 103-114, 1992) and conservation of yellow substance, it is argued that the long-term average composition of the bottom layer inflow to the Kattegat from the Skagerrak consists of about 90% North Sea/Atlantic water and 10% German Bight/Southern North Sea water. The German Bight content estimate is substantially lower than the ones given in earlier studies (50-67%) and implies that the Jutland Coastal Current only has a small impact on the water quality of the Kattegat.

  6. Development and validation of a logistic regression model to distinguish transition zone cancers from benign prostatic hyperplasia on multi-parametric prostate MRI

    Energy Technology Data Exchange (ETDEWEB)

    Iyama, Yuji [Kumamoto Chuo Hospital, Department of Diagnostic Radiology, Kumamoto, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto, Kumamoto (Japan); Nakaura, Takeshi; Nagayama, Yasunori; Utsunomiya, Daisuke; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto, Kumamoto (Japan); Katahira, Kazuhiro; Oda, Seitaro [Kumamoto Chuo Hospital, Department of Diagnostic Radiology, Kumamoto, Kumamoto (Japan); Iyama, Ayumi [National Hospital Organization Kumamoto Medical Center, Department of Diagnostic Radiology, Kumamoto, Kumamoto (Japan)

    2017-09-15

    To develop a prediction model to distinguish between transition zone (TZ) cancers and benign prostatic hyperplasia (BPH) on multi-parametric prostate magnetic resonance imaging (mp-MRI). This retrospective study enrolled 60 patients with either BPH or TZ cancer, who had undergone 3 T-MRI. We generated ten parameters for T2-weighted images (T2WI), diffusion-weighted images (DWI) and dynamic MRI. Using a t-test and multivariate logistic regression (LR) analysis to evaluate the parameters' accuracy, we developed LR models. We calculated the area under the receiver operating characteristic curve (ROC) of LR models by a leave-one-out cross-validation procedure, and the LR model's performance was compared with radiologists' performance with their opinion and with the Prostate Imaging Reporting and Data System (Pi-RADS v2) score. Multivariate LR analysis showed that only standardized T2WI signal and mean apparent diffusion coefficient (ADC) maintained their independent values (P < 0.001). The validation analysis showed that the AUC of the final LR model was comparable to that of board-certified radiologists, and superior to that of Pi-RADS scores. A standardized T2WI and mean ADC were independent factors for distinguishing between BPH and TZ cancer. The performance of the LR model was comparable to that of experienced radiologists. (orig.)

  7. Influence of the micro- and nanoscale local mechanical properties of the interfacial transition zone on impact behavior of concrete made with different aggregates

    International Nuclear Information System (INIS)

    Erdem, Savaş; Dawson, Andrew Robert; Thom, Nicholas Howard

    2012-01-01

    The influence of the microscale local mechanical properties of the interfacial transition zone (ITZ) on macro-level mechanical response and impact behavior is studied for concretes made with copper slag and gravel aggregates. 3D nanotech vertical scanning interferometry, scanning electron microscopy coupled with energy dispersive X-ray micro-analysis, digital image analysis, and 3D X-ray computed tomography were used to characterize the microstructures and the ITZs. It was deduced that a stronger and denser ITZ in the copper slag specimen would reduce its vulnerability to stiffness loss and contribute to its elastic and more ductile response under impact loading. The analysis also indicated that a significant degeneration in the pore structure of the gravel specimen associated with a relatively weaker and non-homogeneous ITZ occurred under impact. Finally, it was also concluded that increased roughness of ITZ may contribute to the load-carrying capacity of concrete under impact by improving contact point interactions and energy dissipation.

  8. Pilot study of a novel tool for input-free automated identification of transition zone prostate tumors using T2- and diffusion-weighted signal and textural features.

    Science.gov (United States)

    Stember, Joseph N; Deng, Fang-Ming; Taneja, Samir S; Rosenkrantz, Andrew B

    2014-08-01

    To present results of a pilot study to develop software that identifies regions suspicious for prostate transition zone (TZ) tumor, free of user input. Eight patients with TZ tumors were used to develop the model by training a Naïve Bayes classifier to detect tumors based on selection of most accurate predictors among various signal and textural features on T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) maps. Features tested as inputs were: average signal, signal standard deviation, energy, contrast, correlation, homogeneity and entropy (all defined on T2WI); and average ADC. A forward selection scheme was used on the remaining 20% of training set supervoxels to identify important inputs. The trained model was tested on a different set of ten patients, half with TZ tumors. In training cases, the software tiled the TZ with 4 × 4-voxel "supervoxels," 80% of which were used to train the classifier. Each of 100 iterations selected T2WI energy and average ADC, which therefore were deemed the optimal model input. The two-feature model was applied blindly to the separate set of test patients, again without operator input of suspicious foci. The software correctly predicted presence or absence of TZ tumor in all test patients. Furthermore, locations of predicted tumors corresponded spatially with locations of biopsies that had confirmed their presence. Preliminary findings suggest that this tool has potential to accurately predict TZ tumor presence and location, without operator input. © 2013 Wiley Periodicals, Inc.

  9. Factors influencing smallholder farmers' behavioural intention towards adaptation to climate change in transitional climatic zones: A case study of Hwedza District in Zimbabwe.

    Science.gov (United States)

    Zamasiya, Byron; Nyikahadzoi, Kefasi; Mukamuri, Billy Billiard

    2017-08-01

    This paper examines factors influencing behavioural change among smallholder farmers towards adaptation to climate change in transitional climatic zones of Africa, specifically, Hwedza District in Zimbabwe. Data for this study were collected from 400 randomly-selected smallholder farmers, using a structured questionnaire, focus group discussions and key informant interviews. The study used an ordered logit model to examine the factors that influence smallholder farmers' behavioural intention towards adaptation to climate change. Results from the study show that the gender of the household head, access to extension services on crop and livestock production, access to climate information, membership to social groups and experiencing a drought have a positive influence on farmers' attitude towards adaptation to climate change and variability. The study concluded that although the majority of smallholder farmers perceive that the climate is changing, they continue to habour negative attitudes towards prescribed climate change adaptation techniques. This study recommends more education on climate change, as well as adaptation strategies for both agricultural extension workers and farmers. This can be complemented by disseminating timely climate information through extension officers and farmers' groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Palaeoenvironmental implications of a Holocene sequence of lacustrine-peat sediments from the desert-loess transitional zone in Northern China

    Science.gov (United States)

    Jia, Feifei; Lu, Ruijie; Liu, Xiaokang; Zhao, Chao; Lv, Zhiqiang; Gao, Shangyu

    2018-05-01

    A high-resolution lacustrine-peat record from the desert-loess transitional zone in Northern China was obtained to reconstruct Holocene environmental change in the region. AMS 14C dates are used to provide a chronology. The results indicate that the site was a desert environment before 12.2 cal kyr BP, and was then occupied by a paleolake which started to shrink, with a wetland occurring from 6.2 to 3.0 cal kyr BP. Subsequently, the site became a seasonally water-filled depression. Based on the lithology and measurements of grain size and total organic carbon content, the climate changed from arid to humid at 12.2 cal kyr BP, and became more humid after 8.3 cal kyr BP. From 6.2 to 3.0 cal kyr BP, precipitation decreased but the climate remained at an optimum. After 3.0 cal kyr BP, the climate was dry overall but with several humid intervals. A comparison of paleoclimatic records from lacustrine and aeolian deposits from the region reveals a discrepancy about the nature of the early Holocene climate, and we conclude that this is because lacustrine sediments responded more sensitively to precipitation than aeolian deposits when the temperature was low. The environmental evolution of the region was synchronous with changes in the Asian summer monsoon (ASM), but temperature also played a key role in the early Holocene.

  11. Cascading ecohydrological transitions: Multiple changes in vegetation and hydrology over the past 500 years for a semiarid forest/woodland boundary zone in New Mexico, USA

    Science.gov (United States)

    Allen, Craig D.

    2010-05-01

    On decadal and centennial time scales, multiple drivers can cause substantial changes in vegetation cover, which can trigger associated changes in runoff and erosion patterns and processes, with consequent feedbacks to the vegetation - cumulatively this can lead to a cascading series of non-equilibrial ecosystem changes through time. The work reported here provides a relatively detailed 500-year perspective of such changes on the mesas the eastern Jemez Mountains in northern New Mexico (USA), which today exhibit vegetation transitions along an elevational gradient between semiarid ponderosa pine (Pinus ponderosa) forests, mixed woodlands dominated by piñon (Pinus edulis) and one-seed juniper (Juniperus monosperma), and juniper savannas. Using multiple lines of evidence, a history of major ecosystem changes since ca. 1500 A.D. is reconstructed for a dynamic transition zone on one such mesa (Frijolito Mesa). Evidence includes intensive archaeological surveys, dendrochronological reconstructions of the demographic and spatial patterns of establishment and mortality for these three main tree species, dendrochronological reconstructions of fire regimes and climate patterns, broad-scale mapping of vegetation changes from historic aerial photographs since 1935, monitoring of vegetation from permanent transects since 1991, detailed soil maps and interpretations, intensive ecohydrological studies since 1993 on portions of this mesa, and research on the ecosystem effects of an experimental tree-thinning experiment conducted in 1997. Frijolito Mesa was fully occupied by large numbers of Native American farmers from the A.D. 1200's until the late 1500's, when they left these mesas for settlements in the adjoining Rio Grande Valley. Archaeological evidence and tree ages indicate that the mesa was likely quite deforested when abandoned, followed by episodic tree establishment dominated by ponderosa pine during the Little Ice Age. By the late 1700's Frijolito Mesa included

  12. Isosymmetric pressure-induced bonding increase changes compression behavior of clinopyroxenes across jadeite-aegirine solid solution in subduction zones: ISOSYMMETRIC PHASE TRANSITION

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jingui [Key Laboratory of High Temperature and High Pressure Study of the Earth' s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang China; Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Mānoa, Honolulu Hawaii USA; University of Chinese Academy of Sciences, Beijing China; Zhang, Dongzhou [Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Mānoa, Honolulu Hawaii USA; Fan, Dawei [Key Laboratory of High Temperature and High Pressure Study of the Earth' s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang China; Downs, Robert T. [Department of Geosciences, University of Arizona, Tucson Arizona USA; Hu, Yi [Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Mānoa, Honolulu Hawaii USA; Dera, Przemyslaw K. [Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Mānoa, Honolulu Hawaii USA

    2017-01-01

    Pyroxenes are among the most important minerals of Earth's crust and upper mantle and play significant role in controlling subduction at convergent margins. In this study, synchrotron-based single-crystal X-ray diffraction experiments were carried out on a natural aegirine [NaFe3+Si2O6] sample at ambient temperature and high pressures to 60 GPa, simulating conditions within the coldest part of a subduction zone consisting of old lithosphere. The diffraction data reveal no obvious sign of structural phase transition in aegirine within this pressure range; however, several relevant structural parameter trends change noticeably at approximately 24 GPa, indicating the presence of the previously predicted isosymmetric bonding change, related to increase of coordination number of Na+ at M2 site. The pressure-volume data, fit with third-order Birch-Murnaghan (BM3) equation of state over the whole pressure range, yields KT0 = 126(2) GPa and K'T0 = 3.3(1), while separate BM3 fits performed for the 0–24.0 GPa and 29.9–60.4 GPa pressure ranges give KT0 = 118(3) GPa, K'T0 = 4.2(3) and KT0 = 133(2) GPa, K'T0 = 3.0(1), suggesting that the structure stiffens as a result of the new bond formation. Aegirine exhibits strong anisotropic compression with unit strain axial ratios ε1:ε2:ε3 = 1.00:2.44:1.64. Structural refinements reveal that NaO8 polyhedron is the most compressible and SiO4 tetrahedron has the lowest compressibility. The consequence of bonding transition is that the compressional behavior of aegirine below ~24 GPa and above that pressure is quite different, with likely consequences for relevant thermodynamic parameters and ion diffusion coefficients.

  13. EXOPLANET CHARACTERIZATION BY PROXY: A TRANSITING 2.15 R{sub Circled-Plus} PLANET NEAR THE HABITABLE ZONE OF THE LATE K DWARF KEPLER-61

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Sarah; Charbonneau, David; Fressin, Francois; Torres, Guillermo; Irwin, Jonathan; Newton, Elisabeth [University of Washington, Seattle, WA 98195 (United States); Desert, Jean-Michel; Crepp, Justin R.; Shporer, Avi [California Institute of Technology, Pasadena, CA 91125 (United States); Mann, Andrew W. [Institute for Astronomy, University of Hawai' i, Honolulu, HI 96822 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Henze, Christopher E.; Bryson, Stephen T.; Howell, Steven B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Horch, Elliott P. [Southern Connecticut State University, New Haven, CT 06515 (United States); Everett, Mark E., E-mail: sarahba@uw.edu [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)

    2013-08-20

    We present the validation and characterization of Kepler-61b: a 2.15 R{sub Circled-Plus} planet orbiting near the inner edge of the habitable zone of a low-mass star. Our characterization of the host star Kepler-61 is based upon a comparison with a set of spectroscopically similar stars with directly measured radii and temperatures. We apply a stellar prior drawn from the weighted mean of these properties, in tandem with the Kepler photometry, to infer a planetary radius for Kepler-61b of 2.15 {+-} 0.13 R{sub Circled-Plus} and an equilibrium temperature of 273 {+-} 13 K (given its period of 59.87756 {+-} 0.00020 days and assuming a planetary albedo of 0.3). The technique of leveraging the physical properties of nearby ''proxy'' stars allows for an independent check on stellar characterization via the traditional measurements with stellar spectra and evolutionary models. In this case, such a check had implications for the putative habitability of Kepler-61b: the planet is 10% warmer and larger than inferred from K-band spectral characterization. From the Kepler photometry, we estimate a stellar rotation period of 36 days, which implies a stellar age of >1 Gyr. We summarize the evidence for the planetary nature of the Kepler-61 transit signal, which we conclude is 30,000 times more likely to be due to a planet than a blend scenario. Finally, we discuss possible compositions for Kepler-61b with a comparison to theoretical models as well as to known exoplanets with similar radii and dynamically measured masses.

  14. Expression of Tlx in both stem cells and transit amplifying progenitors regulates stem cell activation and differentiation in the neonatal lateral subependymal zone.

    Science.gov (United States)

    Obernier, Kirsten; Simeonova, Ina; Fila, Tatiana; Mandl, Claudia; Hölzl-Wenig, Gabriele; Monaghan-Nichols, Paula; Ciccolini, Francesca

    2011-09-01

    Niche homeostasis in the postnatal subependymal zone of the lateral ventricle (lSEZ) requires coordinated proliferation and differentiation of neural progenitor cells. The mechanisms regulating this balance are scarcely known. Recent observations indicate that the orphan nuclear receptor Tlx is an intrinsic factor essential in maintaining this balance. However, the effect of Tlx on gene expression depends on age and cell-type cues. Therefore, it is essential to establish its expression pattern at different developmental ages. Here, we show for the first time that in the neonatal lSEZ activated neural stem cells (NSCs) and especially transit-amplifying progenitors (TAPs) express Tlx and that its expression may be regulated at the posttranscriptional level. We also provide evidence that in both cell types Tlx affects gene expression in a positive and negative manner. In activated NSCs, but not in TAPs, absence of Tlx leads to overexpression of negative cell cycle regulators and impairment of proliferation. Moreover, in both cell types, the homeobox transcription factor Dlx2 is downregulated in the absence of Tlx. This is paralleled by increased expression of Olig2 in activated NSCs and glial fibrillary acidic protein in TAPs, indicating that in both populations Tlx decreases gliogenesis. Consistent with this, we found a higher proportion of cells expressing glial makers in the neonatal lSEZ of mutant mice than in the wild type counterpart. Thus, Tlx playing a dual role affects the expression of distinct genes in these two lSEZ cell types. Copyright © 2011 AlphaMed Press.

  15. Response of Glacier and Lake Dynamics in Four Inland Basins to Climate Change at the Transition Zone between the Karakorum And Himalayas.

    Directory of Open Access Journals (Sweden)

    Zhiguo Li

    Full Text Available Inland glacier and lake dynamics on the Tibetan Plateau (TP and its surroundings over recent decades are good indicators of climate change and have a significant impact on the local water supply and ecosystem. The glacier and lake changes in Karakoram are quite different from those of the Himalayas. The mechanisms of the complex and regionally heterogeneous behavior of the glacier and lake changes between the Karakorum and Himalayas are poorly understood. Based on satellite images and meteorological data of Shiquanhe, Hetian, and Yutian stations, we demonstrate that the overall retreat of glaciers and increase of lake area at the transition zone between the Karakoram and Himalayas (TKH have occurred since 1968 in response to a significant global climate change. Glacial areas in the Songmuxi Co basin, Zepu Co basin, Mang Co basin and Unnamed Co decreased by -1.98 ± 0.02 km2, -5.39 ± 0.02 km2, -0.01 ± 0.02 km2, and -0.12 ± 0.02 km2 during the study period, corresponding to losses of -1.42%, -2.86%, -1.54%, and -1.57%, respectively. The lake area of the Songmuxi Co, Zepu Co, Mang Co and Unnamed Co increased by 7.57 ± 0.02 km2, 8.53 ± 0.02 km2, 1.35 ± 0.02 km2, and 0.53 ± 0.02 km2, corresponding to growths of 30.22%, 7.55%, 11.39%, and 8.05%, respectively. Increases in temperature was the main reason for glacier retreat, whereas decreases in potential evapotranspiration of lakes, increases in precipitation, and increases in melt water from glaciers and frozen soil all contributed to lake area expansion.

  16. Effects of flow dynamics on the aquatic-terrestrial transition zone (ATTZ) of lower Missouri river sandbars with implications for selected biota

    Science.gov (United States)

    Tracy-Smith, Emily; Galat, David L.; Jacobson, Robert B.

    2012-01-01

    Sandbars are an important aquatic terrestrial transition zone (ATTZ) in the active channel of rivers that provide a variety of habitat conditions for riverine biota. Channelization and flow regulation in many large rivers have diminished sandbar habitats and their rehabilitation is a priority. We developed sandbar-specific models of discharge-area relationships to determine how changes in flow regime affect the area of different habitat types within the submerged sandbar ATTZ (depth) and exposed sandbar ATTZ (elevation) for a representative sample of Lower Missouri River sandbars. We defined six different structural habitat types within the sandbar ATTZ based on depth or exposed elevation ranges that are important to different biota during at least part of their annual cycle for either survival or reproduction. Scenarios included the modelled natural flow regime, current managed flow regime and two environmental flow options, all modelled within the contemporary river active channel. Thirteen point and wing-dike sandbars were evaluated under four different flow scenarios to explore the effects of flow regime on seasonal habitat availability for foraging of migratory shorebirds and wading birds, nesting of softshell turtles and nursery of riverine fishes. Managed flows provided more foraging habitat for shorebirds and wading birds and more nursery habitat for riverine fishes within the channelized reach sandbar ATTZ than the natural flow regime or modelled environmental flows. Reduced summer flows occurring under natural and environmental flow alternatives increased exposed sandbar nesting habitat for softshell turtle hatchling emergence. Results reveal how management of channelized and flow regulated large rivers could benefit from a modelling framework that couples hydrologic and geomorphic characteristics to predict habitat conditions for a variety of biota.

  17. Stochastic Inversion of Geomagnetic Observatory Data Including Rigorous Treatment of the Ocean Induction Effect With Implications for Transition Zone Water Content and Thermal Structure

    Science.gov (United States)

    Munch, F. D.; Grayver, A. V.; Kuvshinov, A.; Khan, A.

    2018-01-01

    In this paper we estimate and invert local electromagnetic (EM) sounding data for 1-D conductivity profiles in the presence of nonuniform oceans and continents to most rigorously account for the ocean induction effect that is known to strongly influence coastal observatories. We consider a new set of high-quality time series of geomagnetic observatory data, including hitherto unused data from island observatories installed over the last decade. The EM sounding data are inverted in the period range 3-85 days using stochastic optimization and model exploration techniques to provide estimates of model range and uncertainty. The inverted conductivity profiles are best constrained in the depth range 400-1,400 km and reveal significant lateral variations between 400 km and 1,000 km depth. To interpret the inverted conductivity anomalies in terms of water content and temperature, we combine laboratory-measured electrical conductivity of mantle minerals with phase equilibrium computations. Based on this procedure, relatively low temperatures (1200-1350°C) are observed in the transition zone (TZ) underneath stations located in Southern Australia, Southern Europe, Northern Africa, and North America. In contrast, higher temperatures (1400-1500°C) are inferred beneath observatories on islands, Northeast Asia, and central Australia. TZ water content beneath European and African stations is ˜0.05-0.1 wt %, whereas higher water contents (˜0.5-1 wt %) are inferred underneath North America, Asia, and Southern Australia. Comparison of the inverted water contents with laboratory-constrained water storage capacities suggests the presence of melt in or around the TZ underneath four geomagnetic observatories in North America and Northeast Asia.

  18. EXOPLANET CHARACTERIZATION BY PROXY: A TRANSITING 2.15 R⊕ PLANET NEAR THE HABITABLE ZONE OF THE LATE K DWARF KEPLER-61

    International Nuclear Information System (INIS)

    Ballard, Sarah; Charbonneau, David; Fressin, Francois; Torres, Guillermo; Irwin, Jonathan; Newton, Elisabeth; Desert, Jean-Michel; Crepp, Justin R.; Shporer, Avi; Mann, Andrew W.; Ciardi, David R.; Henze, Christopher E.; Bryson, Stephen T.; Howell, Steven B.; Horch, Elliott P.; Everett, Mark E.

    2013-01-01

    We present the validation and characterization of Kepler-61b: a 2.15 R ⊕ planet orbiting near the inner edge of the habitable zone of a low-mass star. Our characterization of the host star Kepler-61 is based upon a comparison with a set of spectroscopically similar stars with directly measured radii and temperatures. We apply a stellar prior drawn from the weighted mean of these properties, in tandem with the Kepler photometry, to infer a planetary radius for Kepler-61b of 2.15 ± 0.13 R ⊕ and an equilibrium temperature of 273 ± 13 K (given its period of 59.87756 ± 0.00020 days and assuming a planetary albedo of 0.3). The technique of leveraging the physical properties of nearby ''proxy'' stars allows for an independent check on stellar characterization via the traditional measurements with stellar spectra and evolutionary models. In this case, such a check had implications for the putative habitability of Kepler-61b: the planet is 10% warmer and larger than inferred from K-band spectral characterization. From the Kepler photometry, we estimate a stellar rotation period of 36 days, which implies a stellar age of >1 Gyr. We summarize the evidence for the planetary nature of the Kepler-61 transit signal, which we conclude is 30,000 times more likely to be due to a planet than a blend scenario. Finally, we discuss possible compositions for Kepler-61b with a comparison to theoretical models as well as to known exoplanets with similar radii and dynamically measured masses

  19. Cranial nerve vascular compression syndromes of the trigeminal, facial and vago-glossopharyngeal nerves: comparative anatomical study of the central myelin portion and transitional zone; correlations with incidences of corresponding hyperactive dysfunctional syndromes.

    Science.gov (United States)

    Guclu, Bulent; Sindou, Marc; Meyronet, David; Streichenberger, Nathalie; Simon, Emile; Mertens, Patrick

    2011-12-01

    The aim of this study was to evaluate the anatomy of the central myelin portion and the central myelin-peripheral myelin transitional zone of the trigeminal, facial, glossopharyngeal and vagus nerves from fresh cadavers. The aim was also to investigate the relationship between the length and volume of the central myelin portion of these nerves with the incidences of the corresponding cranial dysfunctional syndromes caused by their compression to provide some more insights for a better understanding of mechanisms. The trigeminal, facial, glossopharyngeal and vagus nerves from six fresh cadavers were examined. The length of these nerves from the brainstem to the foramen that they exit were measured. Longitudinal sections were stained and photographed to make measurements. The diameters of the nerves where they exit/enter from/to brainstem, the diameters where the transitional zone begins, the distances to the most distal part of transitional zone from brainstem and depths of the transitional zones were measured. Most importantly, the volume of the central myelin portion of the nerves was calculated. Correlation between length and volume of the central myelin portion of these nerves and the incidences of the corresponding hyperactive dysfunctional syndromes as reported in the literature were studied. The distance of the most distal part of the transitional zone from the brainstem was 4.19  ±  0.81 mm for the trigeminal nerve, 2.86  ±  1.19 mm for the facial nerve, 1.51  ±  0.39 mm for the glossopharyngeal nerve, and 1.63  ±  1.15 mm for the vagus nerve. The volume of central myelin portion was 24.54  ±  9.82 mm(3) in trigeminal nerve; 4.43  ±  2.55 mm(3) in facial nerve; 1.55  ±  1.08 mm(3) in glossopharyngeal nerve; 2.56  ±  1.32 mm(3) in vagus nerve. Correlations (p  nerves and incidences of the corresponding diseases. At present it is rather well-established that primary trigeminal neuralgia, hemifacial spasm and vago

  20. Monitoring Soil Erosion on a Burned Site in the Mojave-Great Basin Transition Zone: Final Report for the Jacob Fire Site

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Julianne [DRI; Etyemezian, Vic [DRI; Cablk, Mary E. [DRI; Shillito, Rose [DRI; Shafer, David [DOE Grand Junction, Colorado

    2013-06-01

    A historic return interval of 100 years for large fires in the U.S. southwestern deserts is being replaced by one where fires may reoccur as frequently as every 20 to 30 years. The shortened return interval, which translates to an increase in fires, has implications for management of Soil Corrective Action Units (CAUs) and Corrective Action Sites (CASs) for which the Department of Energy, National Nuclear Security Administration Nevada Field Office has responsibility. A series of studies was initiated at uncontaminated analog sites to better understand the possible impacts of erosion and transport by wind and water should contaminated soil sites burn. The first of these studies was undertaken at the Jacob Fire site approximately 12 kilometers (7.5 miles) north of Hiko, Nevada. A lightning-caused fire burned approximately 200 hectares during August 6-8, 2008. The site is representative of a transition between Mojave and Great Basin desert ecoregions on the Nevada National Security Site (NNSS), where the largest number of Soil CAUs/CASs are located. The area that burned at the Jacob Fire site was primarily a Coleogyne ramosissima (blackbrush) and Ephedra nevadensis (Mormon tea) community, also an abundant shrub assemblage in the similar transition zone on the NNSS. This report summarizes three years of measurements after the fire. Seven measurement campaigns at the Jacob Fire site were completed. Measurements were made on burned ridge (upland) and drainage sites, and on burned and unburned sites beneath and between vegetation. A Portable In-Situ Wind Erosion Lab (PI-SWERL) was used to estimate emissions of suspended particles at different wind speeds. Context for these measurements was provided through a meteorological tower that was installed at the Jacob Fire site to obtain local, relevant environmental parameters. Filter samples, collected from the exhaust of the PI-SWERL during measurements, were analyzed for chemical composition. Runoff and water erosion were

  1. Extended Finite Element Method XFEM for ductile tearing: Large crack growth modelization based on the transition from a continuous medium to the crack via a cohesive zone model

    International Nuclear Information System (INIS)

    Simatos, A.

    2010-01-01

    This work extends the applicability of local models for ductile fracture to large crack growth modelization for ductile tearing. This is done inserting a cohesive zone model whose constitutive law is identified in order to be consistent with the local model. The consistency is obtained through the cohesive law incremental construction which ensures the equivalence of the energy and of the mechanical response of the models. The extension of the applicability domain of the local modelization is enabled via the XFEM framework which allows for maintaining the mechanical energy during the crack extension step. This method permits also to introduce the cohesive zone model during the calculation without regards to the mesh of the structure for its maximal tensile stress. To apply the XFEM to ductile tearing, this method is extended to non linear problems (Updated Lagrangian Formulation, large scale yield plasticity). The cohesive zone model grows when the criterion defined in term of porosity, tested at the front of the cohesive crack front, is verified. The cohesive zone growth criterion is determined in order to model most of the damaging phase with the local model to ensure that the modelization takes into account the triaxiality ratio history accurately. The proposed method is applied to the Rousselier local model for ductile fracture in the XFEM framework of Cast3M, the FE software of the CEA. (author) [fr

  2. Impact of PSA density of transition zone as a potential parameter in reducing the number of unnecessary prostate biopsies in patients with psa levels between 2.6 and 10.0 ng/mL.

    Science.gov (United States)

    Castro, Hugo A Socrates; Iared, Wagner; Santos, José Eduardo Mourão; Solha, Raphael Sandes; Shigueoka, David Carlos; Ajzen, Sergio Aron

    2018-04-10

    To assess the accuracy of prostate-specific antigen (PSA) adjusted for the transition zone volume (PSATZ) in predicting prostate cancer by comparing the ability of several PSA parameters in predicting prostate cancer in men with intermediate PSA levels of 2.6 - 10.0 ng/mL and its ability to reduce unnecessary biopsies. This study included 656 patients referred for prostate biopsy who had a serum PSA of 2.6 - 10.0 ng/mL. Total prostate and transition zone volumes were measured by transrectal ultrasound using the prolate ellipsoid method. The clinical values of PSA, free-to-total (F/T) ratio, PSA density (PSAD) and PSATZ for the detection of prostate cancer were calculated and statistical comparisons between biopsy-positive (cancer) and biopsy-negative (benign) were conducted. Cancer was detected in 172 patients (26.2%). Mean PSA, PSATZ, PSAD and F/T ratio were 7.5 ng/mL, 0.68 ng/mL/cc. 0.25 ng/mL/cc and 0.14 in patients with prostate cancer and 6.29 ng/mL, 0.30 ng/mL/cc, 0.16 ng/mL/cc and 0.22 in patients with benign biopsies, respectively. ROC curves analysis demonstrated that PSATZ had a higher area under curve (0,838) than F/T ratio (0,806) (PPSA. Compared to other PSA related parameters, it was better in differentiating between prostate cancer and benign prostatic enlargement. Also, PSATZ could reduce a significant number of unnecessary biopsies. Copyright® by the International Brazilian Journal of Urology.

  3. Depth-Dependent Earthquake Properties Beneath Long-Beach, CA: Implications for the Rheology at the Brittle-Ductile Transition Zone

    Science.gov (United States)

    Inbal, A.; Clayton, R. W.; Ampuero, J. P.

    2015-12-01

    Except for a few localities, seismicity along faults in southern California is generally confined to depths shallower than 15 km. Among faults hosting deep seismicity, the Newport-Inglewood Fault (NIF), which traverses the Los-Angeles basin, has an exceptionally mild surface expression and low deformation rates. Moreover, the NIF structure is not as well resolved as other, less well instrumented faults because of poor signal-to-noise ratio. Here we use data from three temporary dense seismic arrays, which were deployed for exploration purposes and contain up to several thousands of vertical geophones, to investigate the properties of deep seismicity beneath Long-Beach (LB), Compton and Santa-Fe Springs (SFS). The latter is located 15 km northeast of the NIF, presumably above a major detachment fault underthrusting the basin.Event detection is carried out using a new approach for microseismic multi-channel picking, in which downward-continued data are back-projected onto the volume beneath the arrays, and locations are derived from statistical analysis of back-projection images. Our technique reveals numerous, previously undetected events along the NIF, and confirms the presence of an active shallow structure gently dipping to the north beneath SFS. Seismicity characteristics vary along the NIF strike and dip. While LB seismicity is uncorrelated with the mapped trace of the NIF, Compton seismicity illuminates a sub-vertical fault that extends down to about 20 km. This result, along with the reported high flux of mantle Helium along the NIF (Boles et al., 2015), suggests that the NIF is deeply rooted and acts as a major conduit for mantle fluids. We find that the LB size distribution obeys the typical power-law at shallow depths, but falls off exponentially for events occurring below 20 km. Because deep seismicity occurs uniformly beneath LB, this transition is attributed to a reduction in seismic asperity density with increasing depth, consistent with a transition

  4. Late Quaternary climatic vegetational shifts in an ecological transition zone of northern Madagascar: insights from genetic analyses of two endemic rodent species.

    Science.gov (United States)

    Rakotoarisoa, J-E; Raheriarisena, M; Goodman, S M

    2013-05-01

    The Loky-Manambato region, located in northern Madagascar, is a biotically rich contact zone between different forest biomes. Local current forest cover is composed of both humid and dry formations, which show elevational stratification. A recent phylogeographical study of a regional dry forest rodent, Eliurus carletoni (subfamily Nesomyinae), found genetic evidence of forest contractions between 18 750 and 7500 years BP, which based on extrapolation of the pollen subfossil record, was thought to be associated with an expansion of local humid forests. Herein, we conduct a genetic test of this hypothesis and focused on populations on two neighbouring massifs of forest-dependent rodent species, one associated with low-elevation dry forests (E. carletoni) and the other with higher elevation humid forests (Eliurus tanala). Using mitochondrial markers and a combination of traditional and coalescent-based phylogeographical, historical demographic and population genetic methods, we found evidence of historical connections between populations of E. tanala. Adjacent populations of E. carletoni and E. tanala exhibit opposite historical demographic patterns, and for both, evidence suggests that historical demographic events occurred within the last 25 000 years BP. These findings strongly support the proposed late Quaternary shifts in the floristic composition of the Loky-Manambato region. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  5. The CO2 exchange of biological soil crusts in a semiarid grass-shrubland at the northern transition zone of the Negev desert, Israel

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2008-10-01

    Full Text Available Biological soil crusts (BSC contribute significantly to the soil surface cover in many dryland ecosystems. A mixed type of BSC, which consists of cyanobacteria, mosses and cyanolichens, constitutes more than 60% of ground cover in the semiarid grass-shrub steppe at Sayeret Shaked in the northern Negev Desert, Israel. This study aimed at parameterizing the carbon sink capacity of well-developed BSC in undisturbed steppe systems. Mobile enclosures on permanent soil borne collars were used to investigate BSC-related CO2 fluxes in situ and with natural moisture supply during 10 two-day field campaigns within seven months from fall 2001 to summer 2002. Highest BSC-related CO2 deposition between –11.31 and –17.56 mmol m−2 per 15 h was found with BSC activated from rain and dew during the peak of the winter rain season. Net CO2 deposition by BSC was calculated to compensate 120%, –26%, and less than 3% of the concurrent soil CO2 efflux from November–January, February–May and November–May, respectively. Thus, BSC effectively compensated soil CO2 effluxes when CO2 uptake by vascular vegetation was probably at its low point. Nighttime respiratory emission reduced daily BSC-related CO2 deposition within the period November–January by 11–123% and on average by 27%. The analysis of CO2 fluxes and water inputs from the various sources showed that the bulk of BSC-related CO2 deposition occurs during periods with frequent rain events and subsequent condensation from water accumulated in the upper soil layers. Significant BSC activity on days without detectable atmospheric water supply emphasized the importance of high soil moisture contents as additional water source for soil-dwelling BSC, whereas activity upon dew formation at low soil water contents was not of major importance for BSC-related CO2 deposition. However, dew may still be important in attaining a pre-activated status during the transition from a long "summer" anabiosis towards

  6. Very low frequency electromagnetic (VLF-EM) and electrical resistivity (ER) investigation for groundwater potential evaluation in a complex geological terrain around the Ijebu-Ode transition zone, southwestern Nigeria

    International Nuclear Information System (INIS)

    Osinowo, Olawale O; Olayinka, A Idowu

    2012-01-01

    Groundwater exploration in either a basement or sedimentary environment is often fairly well defined and focuses on delineating weathered/fractured rocks or saturated formations, respectively. Conversely, unique geological structures, the complex coexistence of different rock types and poorly defined basal/lateral contacts between basement and sedimentary rocks make groundwater development in a geological transition environment very challenging. Ijebu-Ode and its environs lie within such a problematic transition zone, between the Precambrian basement rocks and Cretaceous sediments of the Dahomey Basin, in southwestern Nigeria, where associated acute groundwater development challenges require adequate subsurface information to maximize its groundwater resource potential. This study integrated very low frequency electromagnetic (VLF-EM) and electrical resistivity (ER) geophysical prospecting techniques for a detailed terrain study of Ijebu-Ode in order to establish the reasons for the low groundwater resource potential in the area. Thirty five VLF-EM profiles, 140 vertical electrical soundings (VES) and relevant hydrogeological data were acquired along grids and profiles. Data were filtered, inverted and enhanced using appropriate software packages. The current density and geoelectric parameters of the VLF-EM and VES data were employed to generate terrain maps, the conductivity distribution and a subsurface basement model of the study area. Current density plots and geoelectric parameters identified up to three layers in the basement complex terrain which comprised lateritic topsoil, weathered basement and fresh basement rocks. The five layers encountered in the sedimentary terrain were topsoil, a lateritic unit, a dry sandy unit, a saturated sandy unit and fresh basement rocks. The hydraulic conductivity of the thick (3–18 m) lateritic unit was determined to be 1.32 × 10 −5 mm s −1 , while that of the underlying sandy units ranged from 2.65 × 10 −4 to 1

  7. Crustal structure and mantle transition zone thickness beneath a hydrothermal vent at the ultra-slow spreading Southwest Indian Ridge (49°39'E): a supplementary study based on passive seismic receiver functions

    Science.gov (United States)

    Ruan, Aiguo; Hu, Hao; Li, Jiabiao; Niu, Xiongwei; Wei, Xiaodong; Zhang, Jie; Wang, Aoxing

    2017-06-01

    As a supplementary study, we used passive seismic data recorded by one ocean bottom seismometer (OBS) station (49°41.8'E) close to a hydrothermal vent (49°39'E) at the Southwest Indian Ridge to invert the crustal structure and mantle transition zone (MTZ) thickness by P-to-S receiver functions to investigate previous active seismic tomographic crustal models and determine the influence of the deep mantle thermal anomaly on seafloor hydrothermal venting at an ultra-slow spreading ridge. The new passive seismic S-wave model shows that the crust has a low velocity layer (2.6 km/s) from 4.0 to 6.0 km below the sea floor, which is interpreted as partial melting. We suggest that the Moho discontinuity at 9.0 km is the bottom of a layer (2-3 km thick); the Moho (at depth of 6-7 km), defined by active seismic P-wave models, is interpreted as a serpentinized front. The velocity spectrum stacking plot made from passive seismic data shows that the 410 discontinuity is depressed by 15 km, the 660 discontinuity is elevated by 18 km, and a positive thermal anomaly between 182 and 237 K is inferred.

  8. Sound Zones

    DEFF Research Database (Denmark)

    Møller, Martin Bo; Olsen, Martin

    2017-01-01

    Sound zones, i.e. spatially confined regions of individual audio content, can be created by appropriate filtering of the desired audio signals reproduced by an array of loudspeakers. The challenge of designing filters for sound zones is twofold: First, the filtered responses should generate...... an acoustic separation between the control regions. Secondly, the pre- and post-ringing as well as spectral deterioration introduced by the filters should be minimized. The tradeoff between acoustic separation and filter ringing is the focus of this paper. A weighted L2-norm penalty is introduced in the sound...

  9. Nuclear weapons free zones

    International Nuclear Information System (INIS)

    Stahl, K.

    1990-01-01

    The article analyses the concept and problems of the two nuclear weapons free zones in Latin America and in the South Pacific established by the Treaty of Tlatelolco and the Treaty of Rarotonga. So far the nuclear weapons states except China have refused to sign the additional protocols of the Treaties or have signed them only with considerable provisos. Therefore they don't fully recognize the nuclear weapons free status of those zones, or they don't recognize it at all. Both Treaties contain no provisions to regulate the transit of nuclear weapons through the zones. This allows de facto the stationing of nuclear weapons in the military bases of the US which are located within the nuclear weapons free zone of Latin America. The Treaty of Tlatelolco contains also the right of the states, party to the Treaty, to explode nuclear devices for peaceful purposes. Since peaceful and military nuclear explosions cannot be distinguished technically, this right could also undermine the nuclear weapons free status of the region. Important nuclear threshold countries like Argentina and Brazil have furthermore refrained from putting the Treaty into force. (orig.) [de

  10. Focusing on the Interfaces, Estuaries and Redox Transition Zones, for Understanding the Microbial Processes and Biogeochemical Cycling of Carbon under the Looming Influence of Global Warming and Anthropogenic Perturbations

    Science.gov (United States)

    Dang, H.; Jiao, N.

    2013-12-01

    the phytoplankton, zooplankton and fish communities in major world estuaries and coastal oceans. However, due to the rapid evolution rate and high adaptive nature of environmental microorganisms, global warming and anthropogenic perturbations may change the structure and function of the aquatic microbial communities. The estuarine redox transition zones may harbor diverse and novel microbial function groups and communities. How the different microbial processes may influence the ecological functionality and efficiency of estuarine ecosystems needs to be thoroughly investigated to be fully understood.

  11. Intercellular communication within the rat anterior pituitary gland. XV. Properties of spontaneous and LHRH-induced Ca2+ transients in the transitional zone of the rat anterior pituitary in situ.

    Science.gov (United States)

    Hattori, Kazuki; Shirasawa, Nobuyuki; Suzuki, Hikaru; Otsuka, Takanobu; Wada, Ikuo; Yashiro, Takashi; Herbert, Damon C; Soji, Tsuyoshi; Hashitani, Hikaru

    2013-01-01

    In the transitional zone of the rat anterior pituitary, spontaneous and LHRH-induced Ca(2+) dynamics were visualized using fluo-4 fluorescence Ca(2+) imaging. A majority of cells exhibited spontaneous Ca(2+) transients, while small populations of cells remained quiescent. Approximately 70% of spontaneously active cells generated fast, oscillatory Ca(2+) transients that were inhibited by cyclopiazonic acid (10 μm) but not nicardipine (1 μm), suggesting that Ca(2+) handling by endoplasmic reticulum, but not Ca(2+) influx through voltage-dependent L-type Ca(2+) channels, plays a fundamental role in their generation. In the adult rat anterior pituitary, LHRH (100 μg/ml) caused a transient increase in the Ca(2+) level in a majority of preparations taken from the morning group rats killed between 0930 h and 1030 h. However, the second application of LHRH invariably failed to elevate Ca(2+) levels, suggesting that the long-lasting refractoriness to LHRH stimulation was developed upon the first challenge of LHRH. In contrast, LHRH had no effect in most preparations taken from the afternoon group rats euthanized between 1200 h and 1400 h. In the neonatal rat anterior pituitary, LHRH caused a suppression of spontaneous Ca(2+) transients. Strikingly, the second application of LHRH was capable of reproducing the suppression of Ca(2+) signals, indicating that the refractoriness to LHRH had not been established in neonatal rats. These results suggest that responsiveness to LHRH has a long-term refractoriness in adult rats, and that the physiological LHRH surge may be clocked in the morning. Moreover, LHRH-induced excitation and associated refractoriness appear to be incomplete in neonatal rats and may be acquired during development.

  12. Coastal zone

    International Nuclear Information System (INIS)

    2002-01-01

    The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on the coastal zone focuses on the impact of climate change on Canada's marine and Great Lakes coasts with tips on how to deal with the impacts associated with climate change in sensitive environments. This report is aimed at the sectors that will be most affected by adaptation decisions in the coastal zone, including fisheries, tourism, transportation and water resources. The impact of climate change in the coastal zone may include changes in water levels, wave patterns, storm surges, and thickness of seasonal ice cover. The Intergovernmental Panel on Climate Change projects global average sea level will rise between 9 and 88 centimetres between 1990 to 2100, but not all areas of Canada will experience the same rate of future sea level change. The main physical impact would be shoreline change that could result in a range of biophysical and socio-economic impacts, some beneficial, some negative. The report focuses on issues related to infrastructure and communities in coastal regions. It is noted that appropriate human adaptation will play a vital role in reducing the extent of potential impacts by decreasing the vulnerability of average zone to climate change. The 3 main trends in coastal adaptation include: (1) increase in soft protection, retreat and accommodation, (2) reliance on technology such as geographic information systems to manage information, and (3) awareness of the need for coastal adaptation that is appropriate for local conditions. 61 refs., 7 figs

  13. Fatigue properties for the fracture strength of columnar accessory minerals embedded within metamorphic tectonites: implications for stress magnitude in continental crust at the depth of the brittle-plastic transition zone

    Science.gov (United States)

    Kimura, N.; Iwashita, N.; Masuda, T.

    2009-04-01

    1. Introduction Previous studies have compiled yield-strength profiles of continental lithosphere based on the results of laboratory measurements and numerical calculations; however, yield-strength values remain poorly constrained, especially at depths below the brittle-plastic transition zone. Recent studies by the authors have refined the microboudin technique for estimating palaeostress magnitude in the deep crust (> 10 km depth). This technique has the potential to provide important information on stress levels in the deep continental crust, an environment to which available in situ stress measurements and palaeopiezometric methods cannot be applied. In applying the microboudinage technique, obtaining an estimate of the palaeostress magnitude requires knowledge of the fracture strength of columnar accessory minerals (e.g., tourmaline, amphibole, and epidote) that are subjected to brittle fracturing during plastic deformation of the surrounding matrix minerals. The absolute magnitude of fracture strength is known to show a marked reduction in the case of fatigue fracture. Fatigue fracture falls into two categories: static fatigue and cyclic fatigue. In the field of experimental rock deformation, stress corrosion by water molecules (static fatigue) is commonly invoked as the mechanism of fatigue fracture; however, evidence of both static and cyclic fatigue has been reported from studies of natural geological samples. The present study focused on the fatigue properties of columnar accessory minerals at high temperatures, with the aim of improving the accuracy of estimates of natural palaeostress magnitude at depth in the crust. 2. Constant stress-rate test A constant stress-rate test was performed to determine the influence of static fatigue on the strength of columnar accessory minerals. The test was conducted under three-point bending with a span distance of 10 mm. Temperature conditions and the crosshead speed were set in the ranges of ambient to 600°C, and 0

  14. From hilltop to kettle hole: what trends across the terrestrial-aquatic transition zone are revealed by organic matter stable isotope (δ13C and δ15N) composition?

    Science.gov (United States)

    Kayler, Z. E.; Nitzsche, K. N.; Gessler, A.; Kaiser, M. L.; Hoffmann, C.; Premke, K.; Ellerbrock, R.

    2016-12-01

    fractions. At the kettle hole catchment scale, we found that the terrestrial-aquatic transition zone and other areas with high soil moisture correlated with isotopic patterns of the OM fractions. Kettle hole sediment OM fraction patterns were consistently different despite receiving substantial material from the surrounding landscape.

  15. Biogeografía de la Zona de Transición Mexicana con base en un análisis de árboles reconciliados Biogeography of the Mexican Transition Zone based on a reconciled trees analysis

    Directory of Open Access Journals (Sweden)

    Alejandra Miguez-Gutiérrez

    2013-03-01

    of the Mexican Transition Zone through 3 hypotheses of regionalization. We used a reconciled trees method based on the phylogenies of 10 genera of beetles, gymnosperms, lizards and snakes. Seven general area cladograms were generated using assumptions 0 and 1 and the Nelson and majority consensus. They showed 2 groups of areas, 1 with Neotropical affinities and the other with Nearctic affinities. The Sierra Madre del Sur resulted as the sister area of the Trans-Mexican Volcanic Belt. Other constant patterns were the area that involves Tamaulipas and Texas as sister area of the Chihuahuan and Sonoran deserts, and the highlands of Chiapas and Guatemala were always recovered as the sister area of the Talamanca ridge. Our results suggest that the most important vicariant events within the Mexican Transition Zone are the Trans-Mexican Volcanic Belt, which divides the majority of the endemism areas with Neartic affinities (north to this from those endemism areas of Neotropical affinities (south to this and the Tehuantepec Isthmus; which together with the Nicaraguan depression isolates Nuclear Central America. Other patterns appear in either regionalization proposal, but not within the 3, and require future studies in order to find well supported explanations. Even though our results have appeared in previous hypotheses, there are worth due to the fact that we include phylogenetic information of different taxa, we employed reconciled trees, an insufficiently used method, and we searched for congruence between results using 3 regionalization proposals.

  16. Root zone effects on tracer migration in arid zones

    International Nuclear Information System (INIS)

    Tyler, S.W.; Walker, G.R.

    1994-01-01

    The study of groundwater recharge and soil water movement in arid regions has received increased attention in the search for safe disposal sites for hazardous wastes. In passing through the upper 1 to 2 m of most soil profiles, tracers indicative of recharge such as Cl, 2 H, 18 O, Br, 3 H, and 56 Cl are subjected to a wide range of processes not encountered deeper in the profile. This transition zone, where water enters as precipitation and leaves as recharge, is often ignored when environmental tracers are used to estimate deep soil water flux and recharge, yet its effect may be profound. In this work, we reexamine the processes of root extraction and its effect on the velocity and distribution of tracers. Examples are presented for idealized conditions, which show clearly the relation between the root zone processes and the deep drainage or recharge. The results indicate that, when recharge is small and root zone processes are not accounted for, tracer techniques can significantly overestimate recharge until the tracer has moved well below the root zone. By incorporating simple models of root zone processes, a clearer understanding of tracer distributions and a more accurate estimate of recharge can then be made. 11 refs., 9 figs

  17. Zone separator for multiple zone vessels

    Science.gov (United States)

    Jones, John B.

    1983-02-01

    A solids-gas contact vessel, having two vertically disposed distinct reaction zones, includes a dynamic seal passing solids from an upper to a lower zone and maintaining a gas seal against the transfer of the separate treating gases from one zone to the other, and including a stream of sealing fluid at the seal.

  18. Metallogeny of subduction zones

    Directory of Open Access Journals (Sweden)

    Sorokhtin N. O.

    2017-03-01

    Full Text Available The paper deals with the multistage mechanism of the Earth's crust enrichment in ore elements in underthrust zones. The processes of metamorphism and the formation of hydrothermal solutions at pulling of the watered oceanic lithospheric plate into the subduction zone have been described. Some physical and chemical transformation regularities of structural-material complexes in these areas and mechanisms of the formation of ore deposits have been discussed. Spatio-temporal patterns of the localization of a number of endogenetic and exogenetic deposits have been described using metallogeny of the Ural and the Verkhoyansk-Kolyma Fold Belts as an example. It has been shown that in nature there are several effective mechanisms of the enrichment of the crust in ore minerals. One of them is the process of pulling into subduction zone of metalliferous sediments and ferromanganese crusts as well as seabed nodules, their metamorphic transformation, partial melting and transition of ore components into magmatic melts and mineralized fluids. In the future this leads to the release of ore material by magmas and hydrothermal solutions into the folded formations of island-arc and Andean types and the formation of igneous, metasomatic and hydrothermal deposits. Another, yet no less powerful natural mechanism of a conveyor enrichment of the crust in ore elements is the process of destruction and sedimentation of mineral deposits formed in the folded areas as well as the formation of placers and their transfer to the marginal parts of the continent. Later, during the collision of active and passive margins of two lithospheric plates, such as the collision of the Kolyma Massif with the eastern part of the Siberian craton in the middle of the Mesozoic there was a thrusting of a younger lithospheric plate over a more ancient one. As a result, the sedimentary sequences of the passive margin of the Siberian plate were submerged and partially melted by the basic magmas

  19. Empowering the child and caregiver: yellow zone Asthma Action Plan.

    Science.gov (United States)

    Dinakar, Chitra; Portnoy, Jay M

    2014-11-01

    Current guidelines, both national and international, elegantly describe evidence-based measures to attain and maintain long-term control of asthma. These strategies, typically discussed between the provider and patient, are provided in the form of written (or electronic) instructions as part of the green zone of the color-coded Asthma Action Plan. The red zone of the Asthma Action Plan has directives on when to use systemic corticosteroids and seek medical attention. The transition zone between the green zone of good control and the red zone of asthma exacerbation is the yellow zone. This zone guides the patient on self-management of exacerbations outside a medical setting. Unfortunately, the only recommendation currently available to patients per the current asthma guidelines is the repetitive use of reliever bronchodilators. This approach, while providing modest symptom relief, does not reliably prevent progression to the red zone. In this document, we present new, evidence-based, yellow zone intervention options.

  20. Transitional Justice

    DEFF Research Database (Denmark)

    Gissel, Line Engbo

    This presentation builds on an earlier published article, 'Contemporary Transitional Justice: Normalising a Politics of Exception'. It argues that the field of transitional justice has undergone a shift in conceptualisation and hence practice. Transitional justice is presently understood to be th...... to be the provision of ordinary criminal justice in contexts of exceptional political transition.......This presentation builds on an earlier published article, 'Contemporary Transitional Justice: Normalising a Politics of Exception'. It argues that the field of transitional justice has undergone a shift in conceptualisation and hence practice. Transitional justice is presently understood...

  1. Radiation protection zoning

    International Nuclear Information System (INIS)

    2015-01-01

    Radiation being not visible, the zoning of an area containing radioactive sources is important in terms of safety. Concerning radiation protection, 2 work zones are defined by regulations: the monitored zone and the controlled zone. The ministerial order of 15 may 2006 settles the frontier between the 2 zones in terms of radiation dose rates, the rules for access and the safety standards in both zones. Radioprotection rules and the name of the person responsible for radiation protection must be displayed. The frontier between the 2 zones must be materialized and marked with adequate equipment (specific danger signs and tapes). Both zones are submitted to selective entrance, the access for the controlled zone is limited because of the radiation risk and of the necessity of confining radioactive contamination while the limitation of the access to the monitored zone is due to radiation risk only. (A.C.)

  2. Battlemind Training: Transitioning Home from Combat

    National Research Council Canada - National Science Library

    Castro, Carl A; Hoge, Charles W; Milliken, Charles W; McGurk, Dennis; Adler, Amy B; Cox, Anthony; Bliese, Paul D

    2006-01-01

    .... Destruction, injury, and death were ever present in the combat zone. Transitioning from combat to home can be difficult, and many Soldiers encounter readjustment problems ranging from elevated post-traumatic stress disorder (PTSD...

  3. Shear zones between rock units with no relative movement

    DEFF Research Database (Denmark)

    Koyi, Hemin; Schmeling, Harro; Burchardt, Steffi

    2013-01-01

    Shear zones are normally viewed as relatively narrow deformation zones that accommodate relative displacement between two "blocks" that have moved past each other in opposite directions. This study reports localized zones of shear between adjacent blocks that have not moved past each other. Such ...... given credit for and may be responsible for some reverse kinematics reported in shear zones....... or wakes, elongated bodies (vertical plates or horizontal rod-like bodies) produce tabular shear zones or wakes. Unlike conventional shear zones across which shear indicators usually display consistent symmetries, shear indicators on either side of the shear zone or wake reported here show reverse...... kinematics. Thus profiles exhibit shear zones with opposed senses of movement across their center-lines or -planes.We have used field observations and results from analytical and numerical models to suggest that examples of wakes are the transit paths that develop where denser blocks sink within salt...

  4. Supporting Transition

    Science.gov (United States)

    Qureshi, Asima; Petrucco, James

    2018-01-01

    Meadowbrook Primary School has explored the use of The Teacher Assessment in Primary Science (TAPS) to support transition, initially for transfer to secondary school and now for transition from Early Years Foundation Stage (EYFS) into Key Stage 1 (ages 5-7). This article will consider an example of a secondary transition project and discuss the…

  5. Transition radiation and transition scattering

    International Nuclear Information System (INIS)

    Ginzburg, V.L.

    1982-01-01

    Transition radiation is a process of a rather general character. It occurs when some source, which does not have a proper frequency (for example, a charge) moves at a constant velocity in an inhomogeneous and (or) nonstationary medium or near such a medium. The simplest type of transition radiation takes place when a charge crosses a boundary between two media (the role of one of the media may be played by vacuum). In the case of periodic variation of the medium, transition radiation possesses some specific features (resonance transition radiation or transition scattering). Transition scattering occurs, in particular, when a permittivity wave falls onto an nonmoving (fixed) charge. Transition scattering is closely connected with transition bremsstrahlung radiation. All these transition processes are essential for plasma physics. Transition radiation and transition scattering have analogues outside the framework of electrodynamics (like in the case of Vavilov-Cherenkov radiation). In the present report the corresponding range of phenomena is elucidated, as far as possible, in a generally physical aspect. (Auth.)

  6. Zoning Districts - Volusia County HUB Zones

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Historically Underutilized Business (HUB) Zones in Volusia County. Go to http://www.sba.gov/hubzone or contact the Department of Economic Development (386) 248-8048...

  7. TASK 2: QUENCH ZONE SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Fusselman, Steve

    2015-09-30

    Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual

  8. 75 FR 42608 - Safety Zone; Lyme Community Days, Chaumont Bay, NY

    Science.gov (United States)

    2010-07-22

    ...-AA00 Safety Zone; Lyme Community Days, Chaumont Bay, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone for Lyme Community Days Fireworks on Chaumont Bay, Lyme, New York. All vessels are prohibited from transiting the zone except as...

  9. 75 FR 35650 - Safety Zone; Fourth of July Fireworks, City of Sausalito, Sausalito, CA

    Science.gov (United States)

    2010-06-23

    ..., City of Sausalito, safety zone from 11 a.m. through 9:30 p.m. on July 4, 2010, in position 37[deg]51'31... Zone; Fourth of July Fireworks, City of Sausalito, Sausalito, CA AGENCY: Coast Guard, DHS. ACTION... prohibited from entering into, transiting through, or anchoring in the safety zone, unless authorized by the...

  10. 76 FR 63841 - Security Zone; Potomac River, Georgetown Channel, Washington, DC

    Science.gov (United States)

    2011-10-14

    ... effect from 6 a.m. until 6 p.m. on October 16, 2011. The security zone will include all navigable waters... security zone at the time it is in effect are to depart the zone immediately. To seek permission to transit... can better evaluate its effects on them and participate in the rulemaking process. Small businesses...

  11. Phase transitions

    CERN Document Server

    Sole, Ricard V; Solé, Ricard V; Solé, Ricard V; Sol, Ricard V; Solé, Ricard V

    2011-01-01

    Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...

  12. Fracture zones constrained by neutral surfaces in a fault-related fold: Insights from the Kelasu tectonic zone, Kuqa Depression

    Science.gov (United States)

    Sun, Shuai; Hou, Guiting; Zheng, Chunfang

    2017-11-01

    Stress variation associated with folding is one of the controlling factors in the development of tectonic fractures, however, little attention has been paid to the influence of neutral surfaces during folding on fracture distribution in a fault-related fold. In this study, we take the Cretaceous Bashijiqike Formation in the Kuqa Depression as an example and analyze the distribution of tectonic fractures in fault-related folds by core observation and logging data analysis. Three fracture zones are identified in a fault-related fold: a tensile zone, a transition zone and a compressive zone, which may be constrained by two neutral surfaces of fold. Well correlation reveals that the tensile zone and the transition zone reach the maximum thickness at the fold hinge and get thinner in the fold limbs. A 2D viscoelastic stress field model of a fault-related fold was constructed to further investigate the mechanism of fracturing. Statistical and numerical analysis reveal that the tensile zone and the transition zone become thicker with decreasing interlimb angle. Stress variation associated with folding is the first level of control over the general pattern of fracture distribution while faulting is a secondary control over the development of local fractures in a fault-related fold.

  13. Towards stacked zone plates

    International Nuclear Information System (INIS)

    Werner, S; Rehbein, S; Guttman, P; Heim, S; Schneider, G

    2009-01-01

    Fresnel zone plates are the key optical elements for soft and hard x-ray microscopy. For short exposure times and minimum radiation load of the specimen the diffraction efficiency of the zone plate objectives has to be maximized. As the efficiency strongly depends on the height of the diffracting zone structures the achievable aspect ratio of the nanostructures determines these limits. To reach aspect ratios ≥ 20:1 for high efficient optics we propose to superimpose zone plates on top of each other. With this multiplication approach the final aspect ratio is only limited by the number of stacked zone plate layers. For the stack process several nanostructuring process steps have to be developed and/or improved. Our results show for the first time two layers of zone plates stacked on top of each other.

  14. ZoneLib

    DEFF Research Database (Denmark)

    Jessen, Jan Jacob; Schiøler, Henrik

    2006-01-01

    We present a dynamic model for climate in a livestock building divided into a number of zones, and a corresponding modular Simulink library (ZoneLib). While most literature in this area consider air flow as a control parameter we show how to model climate dynamics using actual control signals...... development of ZoneLib....

  15. Transit transparency.

    Science.gov (United States)

    2012-07-01

    Public transit agencies have employed intelligent systems for determining : schedules and routes and for monitoring the real-time location and status of their : vehicle fleets for nearly two decades. But until recently, the data generated by : daily ...

  16. Work zone safety analysis.

    Science.gov (United States)

    2013-11-01

    This report presents research performed analyzing crashes in work zones in the state of New Jersey so as to : identify critical areas in work zones susceptible to crashes and key factors that contribute to these crashes. A field : data collection on ...

  17. Fault zone hydrogeology

    Science.gov (United States)

    Bense, V. F.; Gleeson, T.; Loveless, S. E.; Bour, O.; Scibek, J.

    2013-12-01

    Deformation along faults in the shallow crust (research effort of structural geologists and hydrogeologists. However, we find that these disciplines often use different methods with little interaction between them. In this review, we document the current multi-disciplinary understanding of fault zone hydrogeology. We discuss surface- and subsurface observations from diverse rock types from unlithified and lithified clastic sediments through to carbonate, crystalline, and volcanic rocks. For each rock type, we evaluate geological deformation mechanisms, hydrogeologic observations and conceptual models of fault zone hydrogeology. Outcrop observations indicate that fault zones commonly have a permeability structure suggesting they should act as complex conduit-barrier systems in which along-fault flow is encouraged and across-fault flow is impeded. Hydrogeological observations of fault zones reported in the literature show a broad qualitative agreement with outcrop-based conceptual models of fault zone hydrogeology. Nevertheless, the specific impact of a particular fault permeability structure on fault zone hydrogeology can only be assessed when the hydrogeological context of the fault zone is considered and not from outcrop observations alone. To gain a more integrated, comprehensive understanding of fault zone hydrogeology, we foresee numerous synergistic opportunities and challenges for the discipline of structural geology and hydrogeology to co-evolve and address remaining challenges by co-locating study areas, sharing approaches and fusing data, developing conceptual models from hydrogeologic data, numerical modeling, and training interdisciplinary scientists.

  18. Double seismic zone for deep earthquakes in the izu-bonin subduction zone.

    Science.gov (United States)

    Iidaka, T; Furukawa, Y

    1994-02-25

    A double seismic zone for deep earthquakes was found in the Izu-Bonin region. An analysis of SP-converted phases confirms that the deep seismic zone consists of two layers separated by approximately 20 kilometers. Numerical modeling of the thermal structure implies that the hypocenters are located along isotherms of 500 degrees to 550 degrees C, which is consistent with the hypothesis that deep earthquakes result from the phase transition of metastable olivine to a high-pressure phase in the subducting slab.

  19. VT Data - Zoning 20120709, Huntington

    Data.gov (United States)

    Vermont Center for Geographic Information — Zoning district data for the Town of Huntington, Vermont. For details regarding each zoning district refer to the current zoning regulations on town of Huntington's...

  20. Promise Zones for Applicants

    Data.gov (United States)

    Department of Housing and Urban Development — This tool assists applicants to HUD's Promise Zone initiative prepare data to submit with their application by allowing applicants to draw the exact location of the...

  1. Speeds in school zones.

    Science.gov (United States)

    2009-02-01

    School speed zones are frequently requested traffic controls for school areas, based on the common belief : that if the transportation agency would only install a reduced speed limit, then drivers would no longer : speed through the area. This resear...

  2. Buffer Zone Fact Sheets

    Science.gov (United States)

    New requirements for buffer zones and sign posting contribute to soil fumigant mitigation and protection for workers and bystanders. The buffer provides distance between the pesticide application site and bystanders, reducing exposure risk.

  3. Okeanos Explorer (EX1601): Transit and Mission Patch Test

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Normal underway operations and mapping patch testing. Bathymetric mapping of either the Murray or Molokai Fracture Zones during the transit to Hawaii is planned, as...

  4. Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay.

    Science.gov (United States)

    Huang, Faming; Huang, Boqiang; Huang, Jinliang; Li, Shenghui

    2018-05-23

    Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A), while land change was fastest during the second time interval 2002⁻2009 in a separate terrestrial area within coastal zone (zone B). Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban sustainability in

  5. Quantifying the Variation in Shear Zone Character with Depth: a Case Study from the Simplon Shear Zone, Central Alps

    Science.gov (United States)

    Cawood, T. K.; Platt, J. P.

    2017-12-01

    A widely-accepted model for the rheology of crustal-scale shear zones states that they comprise distributed strain at depth, in wide, high-temperature shear zones, which narrow to more localized, high-strain zones at lower temperature and shallower crustal levels. We test and quantify this model by investigating how the width, stress, temperature and deformation mechanisms change with depth in the Simplon Shear Zone (SSZ). The SSZ marks a major tectonic boundary in the central Alps, where normal-sense motion and rapid exhumation of the footwall have preserved evidence of older, deeper deformation in rocks progressively further into the currently-exposed footwall. As such, microstructures further from the brittle fault (which represents the most localized, most recently-active part of the SSZ) represent earlier, higher- temperature deformation from deeper crustal levels, while rocks closer to the fault have been overprinted by successively later, cooler deformation at shallower depths. This study uses field mapping and microstructural studies to identify zones representing deformation at various crustal levels, and characterize each in terms of zone width (representing width of the shear zone at that time and depth) and dominant deformation mechanism. In addition, quartz- (by Electron Backscatter Diffraction, EBSD) and feldspar grain size (measured optically) piezometry are used to calculate the flow stress for each zone, while the Ti-in-quartz thermometer (TitaniQ) is used to calculate the corresponding temperature of deformation. We document the presence of a broad zone in which quartz is recrystallized by the Grain Boundary Migration (GBM) mechanism and feldspar by Subgrain Rotation (SGR), which represents the broad, deep zone of deformation occurring at relatively high temperatures and low stresses. In map view, this transitions to successively narrower zones, respectively characterized by quartz SGR and feldspar Bulge Nucleation (BLG); quartz BLG and brittle

  6. Identification of Cracked Zone in Sutami dam Using Geoelectrical Method

    Directory of Open Access Journals (Sweden)

    Fina Fitriah

    2015-12-01

    Full Text Available We identified the craked zones based on geoelectrical resistivity method in Sutami Dam. There are four lines measurement of geoelectrical resistivity method with a length of 380-400 meters. The direction of each line is from the northeast to the southwest. All of the tracks are located at the top of Sutami Dam i.e. two tracks in the upstream and the others in the downstream. From the analysis we found that the lithology is detected by geoelectrical resistivty method showed two layers of design of Sutami Dam. The two layers that are detected are transition zone and filter zone. Transition zone consists of sandstone rock containing water (0.922 Ωm-9.57 Ωm and dry sandstone (>9.57 Ωm-320 Ωm. Filter zone consists of sand (>320 Ωm-4410 Ωm. Cracked zones spread in the upstream, downstream, and roadway at the top of Sutami Dam which are indicated by the presence of low resistivity (0.922 Ωm-9.57 Ωm based on 3D processing of data of geoelectrical resistivity. The distribution of cracked zone indicates that Sutami Dam is susceptible to ground movement.

  7. Study of the phase transition dynamics of the L to H transition

    International Nuclear Information System (INIS)

    Moyer, R.A.; Rhodes, T.L.; Rettig, C.L.

    1997-12-01

    A highly radiating zone (MARFE) just above the divertor X-point has been used to access the marginal transition regime P sep ∼ P thres to study the existence of a critical point for the L to H transition. Phase transition models predict that at the critical point, the transition duration increases and the plasma parameters vary continuously between L-mode and H-mode. In these experiments, the L to H transition duration increased 50--100 times over fast transitions. However, the evolution of E r shear, edge density gradient, H-mode pedestal, and fluctuations is essentially unchanged from that in fast transitions. The only difference is in the speed with which and the degree to which the fluctuation amplitudes are transiently reduced. This difference is understandable in terms of the time scales for fluctuation amplitude reduction (≤ 100 micros) and edge pressure gradient increase (several ms), provided the edge fluctuations are pressure-gradient driven

  8. 78 FR 53675 - Eighth Coast Guard District Annual Safety Zones; Boomsday Festival; Tennessee River 646.0-649.0...

    Science.gov (United States)

    2013-08-30

    ...-AA00 Eighth Coast Guard District Annual Safety Zones; Boomsday Festival; Tennessee River 646.0-649.0... Guard will enforce a Safety Zone for the Boomsday Festival Fireworks on the Tennessee River 646.0-649.0... Festival Fireworks. During the enforcement period, entry into, transiting or anchoring in the Safety Zone...

  9. Zones of emotional labour

    DEFF Research Database (Denmark)

    Strøbæk, Pernille Solveig

    2011-01-01

    The paper suggests that due to the difficult nature of their work public family law caseworkers are to be included in the definition of emotional labour even though they are omitted by Hochschild. Based upon a review of the structures involved in emotional labour an explorative qualitative study...... is put forth among 25 Danish public family law caseworkers. The study points to personal, professional, and social zones of emotional labour through which the caseworkers carry out their work. Emotional labour zones mark emotion structures that may be challenging due to complex emotional intersections...

  10. Nuclear free zone

    International Nuclear Information System (INIS)

    Christoffel, T.

    1987-01-01

    Health professionals have played a leading role in alerting and educating the public regarding the danger of nuclear war which has been described as the last epidemic our civilization will know. Having convinced most people that the use of nuclear weapons would mean intolerable consequences, groups such as Physicians for Social Responsibility have focused on the second critical question how likely is it that these weapons will be used? The oultlook is grim. This article describes the nuclear free zone movement, explores relevant legal questions, and shows how the political potential of nuclear free zones threatens to open a deep rift in the American constitutional system

  11. Optimal exploration target zones

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available -of-evidence (WofE) method logistic regression canonical favorability analysis neural networks evidential belief functions Optimal Exploration Target Zones Debba, Carranza, Stein, van der Meer Introduction to Remote Sensing Background and Objective of the study... for the following equation: n∑ i=r ( n i ) pi(1− p)n−i = 0.95 . (1) Optimal Exploration Target Zones Debba, Carranza, Stein, van der Meer Introduction to Remote Sensing Background and Objective of the study Methodology Results METHODS (cont. . . ): FITNESS FUNCTION...

  12. Dike zones on Venus

    Science.gov (United States)

    Markov, M. S.; Sukhanov, A. L.

    1987-01-01

    Venusian dike zone structures were identified from Venera 15 and 16 radar images. These include: a zone of subparallel rows centered at 30 deg N, 7 deg E; a system of intersecting bands centered at 67 deg N, 284 deg E; polygonal systems in lavas covering the structural base uplift centered at 47 deg N, 200 deg E; a system of light bands in the region of the ring structure centered at 43 deg N, 13 deg E; and a dike band centered at 27 deg N, 36 deg E.

  13. Two phase transitions in Nuclear Physics

    International Nuclear Information System (INIS)

    Bes, D.R.

    1985-01-01

    The status of the art of the problem associated with two phase transitions in the nuclear matter, viz.: the disappearance of the nuclear superfluiditiy with the raising of the rotation velocity and the appearance of an octupolar deformation in the actinide zone, is presented. (L.C.) [pt

  14. INTERACTION OF TRADE AND FINANCIAL LINKAGES IN THE FREE TRADE ZONES

    Directory of Open Access Journals (Sweden)

    V. Shevchenko

    2014-09-01

    Full Text Available Different models of free trade agreements (FTA and free trade zones (FTZ are considered in the article, argued the complex approach to their structures and results under unstable global economic environment. The typology of the free trade zones models and financial linkages types between countries have been developed. Approaches to the results of the free trade zones have been argued. It has been discovered that for the free trade zones of transitional countries the prevailing are tarde flows concentration whereas financial and investment linkages are acting with developed countries. The main directions of increasing of the financial linkages results in the free trade zones have been discovered.

  15. A systems approach framework for coastal zones

    DEFF Research Database (Denmark)

    Hopkins, Tom Sawyer; Bailly, Denis; Støttrup, Josianne

    2011-01-01

    This Special Feature Volume examines the potential value of the Systems Approach Framework (SAF) as a methodological framework for the transition to sustainable development in coastal zones. This article provides insight on the Systems Approach, the theory behind it, and how its practical...... application to coastal zone systems (CZSs) was developed. The SAF is about information for management through a focus on how to generate a higher, dynamic level of information about complex CZSs and how to render this information more useful to end users through a participatory suite of communication methods....... The SAF is an open research methodology that investigates the function of systems in order to simulate specific issues or questions concerning their function. The research articles that are included in this Volume demonstrate examples of coupled multidisciplinary methods integrated into SAF simulations...

  16. 77 FR 41902 - Special Local Regulation and Safety Zone; America's Cup Sailing Events, San Francisco, CA

    Science.gov (United States)

    2012-07-17

    ..., operational strategies for the Crissy Field WPA, or an environmental buffer proposed by another agency is... expressed concern that the proposed positioning of the transit zone for 2013 does not fully allow ferry...

  17. Transit space

    DEFF Research Database (Denmark)

    Raahauge, Kirsten Marie

    2008-01-01

    This article deals with representations of one specific city, Århus, Denmark, especially its central district. The analysis is based on anthropological fieldwork conducted in Skåde Bakker and Fedet, two well-off neighborhoods. The overall purpose of the project is to study perceptions of space...... and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...

  18. Transition region

    International Nuclear Information System (INIS)

    Jordan, C.

    1977-01-01

    The Glossary is designed to be a technical dictionary that will provide solar workers of various specialties, students, other astronomers and theoreticians with concise information on the nature and the properties of phenomena of solar and solar-terrestrial physics. Each term, or group of related terms, is given a concise phenomenological and quantitative description, including the relationship to other phenomena and an interpretation in terms of physical processes. The references are intended to lead the non-specialist reader into the literature. This section deals with: transition region; di-electronic recombination; intersystem or intercombination lines; satellite lines; grazing-incidence optics; and crystal spectrometers. (B.R.H.)

  19. CANDIDATE PLANETS IN THE HABITABLE ZONES OF KEPLER STARS

    International Nuclear Information System (INIS)

    Gaidos, Eric

    2013-01-01

    A key goal of the Kepler mission is the discovery of Earth-size transiting planets in ''habitable zones'' where stellar irradiance maintains a temperate climate on an Earth-like planet. Robust estimates of planet radius and irradiance require accurate stellar parameters, but most Kepler systems are faint, making spectroscopy difficult and prioritization of targets desirable. The parameters of 2035 host stars were estimated by Bayesian analysis and the probabilities p HZ that 2738 candidate or confirmed planets orbit in the habitable zone were calculated. Dartmouth Stellar Evolution Program models were compared to photometry from the Kepler Input Catalog, priors for stellar mass, age, metallicity and distance, and planet transit duration. The analysis yielded probability density functions for calculating confidence intervals of planet radius and stellar irradiance, as well as p HZ . Sixty-two planets have p HZ > 0.5 and a most probable stellar irradiance within habitable zone limits. Fourteen of these have radii less than twice the Earth; the objects most resembling Earth in terms of radius and irradiance are KOIs 2626.01 and 3010.01, which orbit late K/M-type dwarf stars. The fraction of Kepler dwarf stars with Earth-size planets in the habitable zone (η ⊕ ) is 0.46, with a 95% confidence interval of 0.31-0.64. Parallaxes from the Gaia mission will reduce uncertainties by more than a factor of five and permit definitive assignments of transiting planets to the habitable zones of Kepler stars.

  20. Splenic marginal zone lymphoma.

    Science.gov (United States)

    Piris, Miguel A; Onaindía, Arantza; Mollejo, Manuela

    Splenic marginal zone lymphoma (SMZL) is an indolent small B-cell lymphoma involving the spleen and bone marrow characterized by a micronodular tumoral infiltration that replaces the preexisting lymphoid follicles and shows marginal zone differentiation as a distinctive finding. SMZL cases are characterized by prominent splenomegaly and bone marrow and peripheral blood infiltration. Cells in peripheral blood show a villous cytology. Bone marrow and peripheral blood characteristic features usually allow a diagnosis of SMZL to be performed. Mutational spectrum of SMZL identifies specific findings, such as 7q loss and NOTCH2 and KLF2 mutations, both genes related with marginal zone differentiation. There is a striking clinical variability in SMZL cases, dependent of the tumoral load and performance status. Specific molecular markers such as 7q loss, p53 loss/mutation, NOTCH2 and KLF2 mutations have been found to be associated with the clinical variability. Distinction from Monoclonal B-cell lymphocytosis with marginal zone phenotype is still an open issue that requires identification of precise and specific thresholds with clinical meaning. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Navigating ECA-Zones

    DEFF Research Database (Denmark)

    Hansen, Carsten Ørts; Grønsedt, Peter; Hendriksen, Christian

    This report examines the effect that ECA-zone regulation has on the optimal vessel fuel strategies for compliance. The findings of this report are trifold, and this report is coupled with a calculation tool which is released to assist ship-owners in the ECA decision making. The first key insight...... much time their operated vessels navigate the ECA in the future....

  2. Buffer Zone Sign Template

    Science.gov (United States)

    The certified pesticide applicator is required to post a comparable sign, designating a buffer zone around the soil fumigant application block in order to control exposure risk. It must include the don't walk symbol, product name, and applicator contact.

  3. Buffer Zone, Nicosia

    OpenAIRE

    Sorensen, Marie Louise

    2010-01-01

    Images of the United Nations Buffer Zone or Green Line which has partitioned Cyprus since 1974 The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7/2007-2013] under grant agreement n° 217411.

  4. Arid Zone Hydrology

    Science.gov (United States)

    Arid zone hydrology encompasses a wide range of topics and hydro-meteorological and ecological characteristics. Although arid and semi-arid watersheds perform the same functions as those in humid environments, their hydrology and sediment transport characteristics cannot be readily predicted by inf...

  5. COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole, E-mail: rory@astro.washington.edu [Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195 (United States)

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  6. COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS

    International Nuclear Information System (INIS)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole

    2015-01-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass–radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions

  7. Remittances to Conflict Zones : the Sudanese Diaspora in Cairo ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Refugees and migrants in transit countries such as Egypt have links to wider diaspora networks that help support them and enable them to support their families back home in conflict zones. However, there is a paucity of literature on such "South-South" remittance flows. The first phase of this project (105040) enabled the ...

  8. Remittances to Conflict Zones : the Sudanese Diaspora in Cairo ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    There has been very little research to date on South-South flows of remittances, for example, remittances between home countries and neighboring countries outside the conflict zone. Refugees and migrants in transit countries such as Egypt belong to networks that help sustain them and enable them to send money to their ...

  9. Cross-shore currents in the surf zone

    DEFF Research Database (Denmark)

    Aagaard, Troels; Vinther, Niels

    2008-01-01

      While the dynamics and kinematics of various types of mean cross-shore current flows in the surf zone (undertow and rip currents) are fairly well understood, the causes for transitions occurring between these two types of mean circulation patterns remain obscure. On longshore barred beaches...

  10. Transitional issues

    International Nuclear Information System (INIS)

    1998-01-01

    This discussion paper, the fifth in the series developed at the IPPSO Market Design Conference, addressed the issue of the need to prevent Ontario Hydro from taking unfair advantage of independent producers and other stakeholders through activities and investments in new power generating capacity in the transitional period leading up to deregulation. The need for controls is predicated on the assumption that the short-term actions and investments of Ontario Hydro could seriously compromise the position of independent generators, and that without such controls the level playing field essential to the operation of a competitive market, does not exist. Various actual and potential actions of Ontario Hydro were discussed, all of which point to the need for strict controls over Ontario Hydro exercising its dominant market power in an unfair way. It was recommended that as a minimum, the provincial government should no longer provide guarantees for Ontario Hydro capital projects, and that Ontario Hydro be instructed to defer any investment on new or returning generating capacity until the new market is in place. Limits could also be placed on Ontario Hydro's marketing efforts to enter into contracts during the transition period, and Ontario Hydro and municipal utilities should be required to keep separate accounts of their commercial preparation, and to settle such accounts separate from ratepayer revenue

  11. Signatures of chaos in the Brillouin zone.

    Science.gov (United States)

    Barr, Aaron; Barr, Ariel; Porter, Max D; Reichl, Linda E

    2017-10-01

    When the classical dynamics of a particle in a finite two-dimensional billiard undergoes a transition to chaos, the quantum dynamics of the particle also shows manifestations of chaos in the form of scarring of wave functions and changes in energy level spacing distributions. If we "tile" an infinite plane with such billiards, we find that the Bloch states on the lattice undergo avoided crossings, energy level spacing statistics change from Poisson-like to Wigner-like, and energy sheets of the Brillouin zone begin to "mix" as the classical dynamics of the billiard changes from regular to chaotic behavior.

  12. Evaluation of Ohio work zone speed zones process.

    Science.gov (United States)

    2014-06-01

    This report describes the methodology and results of analyses performed to determine the effectiveness of Ohio Department of Transportation processes for establishing work zone speed zones. Researchers observed motorists speed choice upstream of a...

  13. Empowerment Zones and Enterprise Districts - MDC_EnterpriseZone

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Polygon feature class of Miami Dade County Enterprise Zones. Enterprise Zones are special areas in the county where certain incentives from the State are available...

  14. Microscale cavitation as a mechanism for nucleating earthquakes at the base of the seismogenic zone.

    Science.gov (United States)

    Verberne, Berend A; Chen, Jianye; Niemeijer, André R; de Bresser, Johannes H P; Pennock, Gillian M; Drury, Martyn R; Spiers, Christopher J

    2017-11-21

    Major earthquakes frequently nucleate near the base of the seismogenic zone, close to the brittle-ductile transition. Fault zone rupture at greater depths is inhibited by ductile flow of rock. However, the microphysical mechanisms responsible for the transition from ductile flow to seismogenic brittle/frictional behaviour at shallower depths remain unclear. Here we show that the flow-to-friction transition in experimentally simulated calcite faults is characterized by a transition from dislocation and diffusion creep to dilatant deformation, involving incompletely accommodated grain boundary sliding. With increasing shear rate or decreasing temperature, dislocation and diffusion creep become too slow to accommodate the imposed shear strain rate, leading to intergranular cavitation, weakening, strain localization, and a switch from stable flow to runaway fault rupture. The observed shear instability, triggered by the onset of microscale cavitation, provides a key mechanism for bringing about the brittle-ductile transition and for nucleating earthquakes at the base of the seismogenic zone.

  15. 76 FR 75450 - Safety Zone; Container Crane Relocation, Cooper and Wando Rivers, Charleston, SC

    Science.gov (United States)

    2011-12-02

    ...-AA00 Safety Zone; Container Crane Relocation, Cooper and Wando Rivers, Charleston, SC AGENCY: Coast... moving safety zone around a barge transporting two container cranes on the Cooper and Wando Rivers during... barge will transit the Cooper and Wando Rivers. Because of the size of the two container cranes and the...

  16. 77 FR 38723 - Safety Zones; Sellwood Bridge Project, Willamette River; Portland, OR

    Science.gov (United States)

    2012-06-29

    ... 138 feet at all times. The safety zone on the western river bank encompasses all waters of the.... These safety zones will ensure the safety of the all vessels and crew that are working and transiting in... rule or any policy or action of the Coast Guard. Collection of Information This rule calls for no new...

  17. Origin of unusual fracture in stirred zone for friction stir welded 2198-T8 Al-Li alloy joints

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Y. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ni, D.R., E-mail: drni@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Xiao, B.L.; Ma, Z.Y. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wu, W.; Zhang, R.X. [AVIC Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024 (China); Zeng, Y.S., E-mail: yszeng@hotmail.com [AVIC Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024 (China)

    2017-05-02

    Friction stir welded (FSW) joints of conventional precipitation-hardened aluminum alloys usually fracture in the lowest hardness zone (LHZ) during tension testing. However, all of the FSW joints of a 2198-T8 Al-Li alloy fractured in the stirred zone (SZ) instead of the LHZ with the welding parameters of 800 rpm-200 mm/min and 1600 rpm-200 mm/min under the condition that no welding defects existed in the SZ. The experiment results revealed that lazy S was not the dominant factor resulting in the unusual fracture. The SZ consisted of three subzones, i.e., the shoulder-affected zone, the pin-affected zone, and the transition zone between them. While the former two zones were characterized by fine and equiaxed recrystallized grains, incompletely dynamically recrystallized microstructure containing coarse elongated non-recrystallized grains was observed in the transition zone. The transition zone exhibited the lowest average Taylor factor in the SZ, resulting in a region that was crystallographically weak. Furthermore, obvious lithium segregation at grain boundaries was observed in the transition zone via time-of-flight secondary ion mass spectroscopy analysis, but not in the shoulder-affected zone or the pin-affected zone. The combined actions of both the two factors resulted in the appearance of preferential intergranular fracture in the transition zone and eventually caused the failure in the SZ. The lithium segregation at grain boundaries in the transition zone was closely associated with both the segregation in the base material and the partially dynamically recrystallized microstructure resulting from the inhomogeneous plastic deformation in the SZ.

  18. Origin of unusual fracture in stirred zone for friction stir welded 2198-T8 Al-Li alloy joints

    International Nuclear Information System (INIS)

    Tao, Y.; Ni, D.R.; Xiao, B.L.; Ma, Z.Y.; Wu, W.; Zhang, R.X.; Zeng, Y.S.

    2017-01-01

    Friction stir welded (FSW) joints of conventional precipitation-hardened aluminum alloys usually fracture in the lowest hardness zone (LHZ) during tension testing. However, all of the FSW joints of a 2198-T8 Al-Li alloy fractured in the stirred zone (SZ) instead of the LHZ with the welding parameters of 800 rpm-200 mm/min and 1600 rpm-200 mm/min under the condition that no welding defects existed in the SZ. The experiment results revealed that lazy S was not the dominant factor resulting in the unusual fracture. The SZ consisted of three subzones, i.e., the shoulder-affected zone, the pin-affected zone, and the transition zone between them. While the former two zones were characterized by fine and equiaxed recrystallized grains, incompletely dynamically recrystallized microstructure containing coarse elongated non-recrystallized grains was observed in the transition zone. The transition zone exhibited the lowest average Taylor factor in the SZ, resulting in a region that was crystallographically weak. Furthermore, obvious lithium segregation at grain boundaries was observed in the transition zone via time-of-flight secondary ion mass spectroscopy analysis, but not in the shoulder-affected zone or the pin-affected zone. The combined actions of both the two factors resulted in the appearance of preferential intergranular fracture in the transition zone and eventually caused the failure in the SZ. The lithium segregation at grain boundaries in the transition zone was closely associated with both the segregation in the base material and the partially dynamically recrystallized microstructure resulting from the inhomogeneous plastic deformation in the SZ.

  19. 75 FR 18755 - Security Zone; Calcasieu River and Ship Channel, LA

    Science.gov (United States)

    2010-04-13

    ...The Coast Guard is disestablishing the permanent safety zone at Trunkline LNG in Lake Charles, LA and replacing it with a security zone with new boundaries. The Coast Guard is also establishing two additional permanent security zones on the waters of the Calcasieu River for the mooring basins at Cameron LNG in Hackberry, LA and PPG Industries in Lake Charles, LA. The Coast Guard is also disestablishing the Calcasieu River ship channel moving safety zone and replacing it with a moving security zone. The revised moving security zone extends channel edge to channel edge on the Calcasieu Channel and shoreline to shoreline on the Calcasieu River, 2 miles ahead and 1 mile astern of certain designated vessels while in transit on the Calcasieu Channel or Calcasieu River. Meeting, crossing or overtaking situations are not permitted within the security zone unless specifically authorized by the Captain of the Port. The moving security zone may commence at any point while certain vessels are transiting the Calcasieu Channel or Calcasieu River on U.S. territorial waters (12 nautical miles) in the Captain of the Port (COTP) Port Arthur zone. These security zones are needed to protect vessels, waterfront facilities, the public, and other surrounding areas from destruction, loss, or injury caused by sabotage, subversive acts, accidents, or other actions of a similar nature. Unless exempted under this rule, entry into or movement within these security zones is prohibited without permission from the Captain of the Port or a designated representative.

  20. 75 FR 43823 - Safety Zone; He'eia Kea Small Boat Harbor, Kaneohe Bay, Oahu, HI

    Science.gov (United States)

    2010-07-27

    ...The Coast Guard is establishing a temporary safety zone in He'eia Kea Small Boat Harbor located in Kaneohe Bay, Oahu, Hawaii. The safety zone is necessary to protect watercraft and the general public from hazards associated with five vessels moored for approximately 3- weeks off the boat harbor's main pier. Vessels desiring to transit through the zone can request permission by contacting the Captain of the Port Honolulu.

  1. Energy transition

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    The yearly environmental conference will hold on September 2013 to evaluate the negotiations led at the national and local levels for december 2012. The government will have then to decide of an energy programming bill which will be submitted to the Parliament at the beginning of the year 2014. 30 main propositions have emerged of the decentralised debates. One of them is the ecological taxation which raise the question of the gas oil and petrol taxation. The current environmental taxes are for almost three quarters of them taxes on energy consumptions and mainly on fossil energies. The Economic, Social and Environmental Council, gives his opinion on the way to find resources to ensure the ecological and energy transition while reducing the public deficit of the State. (O.M.)

  2. Special zone territory decontamination

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Golubev, V.V.

    1989-01-01

    Special zone is the Chernobyl' NPP operating site (OS). OS decontamination is described including reactor ruins from the accident moment. The process was begun from reactor bombardment with absorbing and filtering materials (sand, clay, lead, boron compounds). Then were produced soil shovelling, territory filling by dry concrete and laying concrete layer with thickness up to 300 mm. NPP room and equipment decontamination is described. 3 figs.; 3 tabs

  3. Radiant zone heated particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  4. Cornell Mixing Zone Expert System

    Science.gov (United States)

    This page provides an overview Cornell Mixing Zone Expert System water quality modeling and decision support system designed for environmental impact assessment of mixing zones resulting from wastewater discharge from point sources

  5. VT Data - Zoning 20070306, Marlboro

    Data.gov (United States)

    Vermont Center for Geographic Information — Zoning districts, Marlboro, Vermont. Surface water buffer overlay is in a separate shapefile. Data were originally created by WRC in 2005. Marlboro's zoning bylaw...

  6. Habitable Zones in the Universe

    OpenAIRE

    Gonzalez, G.

    2005-01-01

    Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review...

  7. The Development Evaluation of Economic Zones in China

    Science.gov (United States)

    Shi, Hong-Bo; Zhang, Zhe; Zhai, Yuming; Chen, Quan; Wang, Jiangtao

    2018-01-01

    After the Chinese reform and opening up, the construction of economic zones, such as Special Economic Zones, Hi-tech Zones and Bonded Zones, has played an irreplaceable role in China’s economic development. Currently, against the background of Chinese economic transition, research on development evaluation of economic zones has become popular and necessary. Similar research usually focuses on one specific field, and the methods that are used to evaluate it are simple. This research aims to analyse the development evaluation of zones by synthesis. A new hybrid multiple criteria decision making (MCDM) model that combines the DEMATEL technique and the DANP method is proposed. After establishing the evaluation criterion system and acquiring data, the influential weights of dimensions and criteria can be calculated, which will be a guide for forming measures of development. Shandong Peninsula Blue Economic Zone is used in the empirical case analysis. The results show that Transportation Conditions, Industrial Structure and Business Climate are the main influencing criteria and measures based on these criteria are proposed. PMID:29301304

  8. Transiting Exoplanet Survey Satellite (TESS)

    Science.gov (United States)

    Ricker, G. R.; Clampin, M.; Latham, D. W.; Seager, S.; Vanderspek, R. K.; Villasenor, J. S.; Winn, J. N.

    2012-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. A large fraction of TESS target stars will be 30-100 times brighter than those observed by Kepler satellite, and therefore TESS . planets will be far easier to characterize with follow-up observations. TESS will make it possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for observation with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS data will be released with minimal delay (no proprietary period), inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the very nearest and brightest main-sequence stars hosting transiting exoplanets, thus providing future observers with the most favorable targets for detailed investigations.

  9. Ice films follow structure zone model morphologies

    International Nuclear Information System (INIS)

    Cartwright, Julyan H.E.; Escribano, Bruno; Sainz-Diaz, C. Ignacio

    2010-01-01

    Ice films deposited at temperatures of 6-220 K and at low pressures in situ in a cryo-environmental scanning electron microscope show pronounced morphologies at the mesoscale consistent with the structure zone model of film growth. Water vapour was injected directly inside the chamber at ambient pressures ranging from 10 -4 Pa to 10 2 Pa. Several different substrates were used to exclude the influence of their morphology on the grown films. At the lowest temperatures the ice, which under these conditions is amorphous on the molecular scale, shows the mesoscale morphologies typical of the low-temperature zones of the structure zone model (SZM), including cauliflower, transition, spongelike and matchstick morphologies. Our experiments confirm that the SZM is independent of the chemical nature of the adsorbate, although the intermolecular interactions in water (hydrogen bonds) are different to those in ceramics or metals. At higher temperatures, on the other hand, where the ice is hexagonal crystalline on the molecular scale, it displays a complex palmlike morphology on the mesoscale.

  10. A Systems Approach Framework for Coastal Zones

    Directory of Open Access Journals (Sweden)

    Tom S. Hopkins

    2011-12-01

    Full Text Available This Special Feature Volume examines the potential value of the Systems Approach Framework (SAF as a methodological framework for the transition to sustainable development in coastal zones. This article provides insight on the Systems Approach, the theory behind it, and how its practical application to coastal zone systems (CZSs was developed. The SAF is about information for management through a focus on how to generate a higher, dynamic level of information about complex CZSs and how to render this information more useful to end users through a participatory suite of communication methods. The SAF is an open research methodology that investigates the function of systems in order to simulate specific issues or questions concerning their function. The research articles that are included in this Volume demonstrate examples of coupled multidisciplinary methods integrated into SAF simulations appropriate to a selected policy issue and to the social-environmental conditions of each Study Site Application. Their findings are not the result of funded research projects; instead, they are by-products of pilot applications conducted to develop and improve the SAF methodology. The final article of this Volume synthesizes these results in the context of the SAF as a higher level instrument for integrated coastal zone management.

  11. Ice films follow structure zone model morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, Julyan H.E. [Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, E-18071 Granada (Spain); Escribano, Bruno, E-mail: bruno.escribano.salazar@gmail.co [Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, E-18071 Granada (Spain); Sainz-Diaz, C. Ignacio [Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, E-18071 Granada (Spain)

    2010-04-02

    Ice films deposited at temperatures of 6-220 K and at low pressures in situ in a cryo-environmental scanning electron microscope show pronounced morphologies at the mesoscale consistent with the structure zone model of film growth. Water vapour was injected directly inside the chamber at ambient pressures ranging from 10{sup -4} Pa to 10{sup 2} Pa. Several different substrates were used to exclude the influence of their morphology on the grown films. At the lowest temperatures the ice, which under these conditions is amorphous on the molecular scale, shows the mesoscale morphologies typical of the low-temperature zones of the structure zone model (SZM), including cauliflower, transition, spongelike and matchstick morphologies. Our experiments confirm that the SZM is independent of the chemical nature of the adsorbate, although the intermolecular interactions in water (hydrogen bonds) are different to those in ceramics or metals. At higher temperatures, on the other hand, where the ice is hexagonal crystalline on the molecular scale, it displays a complex palmlike morphology on the mesoscale.

  12. Migration Imaging of the Java Subduction Zones

    Science.gov (United States)

    Dokht, Ramin M. H.; Gu, Yu Jeffrey; Sacchi, Mauricio D.

    2018-02-01

    Imaging of tectonically complex regions can greatly benefit from dense network data and resolution enhancement techniques. Conventional methods in the analysis of SS precursors stack the waveforms to obtain an average discontinuity depth, but smearing due to large Fresnel zones can degrade the fine-scale topography on the discontinuity. To provide a partial solution, we introduce a depth migration algorithm based on the common scattering point method while considering nonspecular diffractions from mantle transition zone discontinuities. Our analysis indicates that, beneath the Sunda arc, the depth of the 410 km discontinuity (the 410) is elevated by 30 km and the 660 km discontinuity (the 660) is depressed by 20-40 km; the region of the strongest anticorrelation is correlated with the morphology of the subducting Indo-Australian slab. In eastern Java, a "flat" 410 coincides with a documented slab gap, showing length scales greater than 400 km laterally and 200 km vertically. This observation could be explained by the arrival of a buoyant oceanic plateau at the Java trench at approximately 8 Ma ago, which may have caused a temporary cessation of subduction and formed a tear in the subducting slab. Our results highlight contrasting depths of the 410 and 660 along the shallow-dipping slab below the Banda trench. The 660, however, becomes significantly uplifted beneath the Banda Sea, which is accompanied by enhanced reflection amplitudes. We interpret these observations as evidence for a subslab low-velocity zone, possibly related to the lower mantle upwelling beneath the subducting slab.

  13. A viscoplastic shear-zone model for episodic slow slip events in oceanic subduction zones

    Science.gov (United States)

    Yin, A.; Meng, L.

    2016-12-01

    Episodic slow slip events occur widely along oceanic subduction zones at the brittle-ductile transition depths ( 20-50 km). Although efforts have been devoted to unravel their mechanical origins, it remains unclear about the physical controls on the wide range of their recurrence intervals and slip durations. In this study we present a simple mechanical model that attempts to account for the observed temporal evolution of slow slip events. In our model we assume that slow slip events occur in a viscoplastic shear zone (i.e., Bingham material), which has an upper static and a lower dynamic plastic yield strength. We further assume that the hanging wall deformation is approximated as an elastic spring. We envision the shear zone to be initially locked during forward/landward motion but is subsequently unlocked when the elastic and gravity-induced stress exceeds the static yield strength of the shear zone. This leads to backward/trenchward motion damped by viscous shear-zone deformation. As the elastic spring progressively loosens, the hanging wall velocity evolves with time and the viscous shear stress eventually reaches the dynamic yield strength. This is followed by the termination of the trenchward motion when the elastic stress is balanced by the dynamic yield strength of the shear zone and the gravity. In order to account for the zig-saw slip-history pattern of typical repeated slow slip events, we assume that the shear zone progressively strengthens after each slow slip cycle, possibly caused by dilatancy as commonly assumed or by progressive fault healing through solution-transport mechanisms. We quantify our conceptual model by obtaining simple analytical solutions. Our model results suggest that the duration of the landward motion increases with the down-dip length and the static yield strength of the shear zone, but decreases with the ambient loading velocity and the elastic modulus of the hanging wall. The duration of the backward/trenchward motion depends

  14. France's seismic zoning

    International Nuclear Information System (INIS)

    Mohammadioun, B.

    1997-01-01

    In order to assess the seismic hazard in France in relation to nuclear plant siting, the CEA, EDF and the BRGM (Mine and Geology Bureau) have carried out a collaboration which resulted in a seismic-tectonic map of France and a data base on seismic history (SIRENE). These studies were completed with a seismic-tectonic zoning, taking into account a very long period of time, that enabled a probabilistic evaluation of the seismic hazard in France, and that may be related to adjacent country hazard maps

  15. Grey zones of welfare

    Directory of Open Access Journals (Sweden)

    Ida Harboe Knudsen

    2015-01-01

    Full Text Available In this article I explore the ‘grey zones of welfare’ in rural Lithuania whereby I point to the inherent ambiguities that lies in a system where people to a high degree rely on networks and normative solutions to everyday shortcomings, rather than on the state. I argue that we in the period after socialism witness an increased degree of informal economies and social arrangements, as the formal sector of social security is perceived as unreliable. This results in a model where liberalism and individual ethics co-exist with a strong morality to support the poorest in society.

  16. Saturated Zone Colloid Transport

    International Nuclear Information System (INIS)

    H. S. Viswanathan

    2004-01-01

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R col is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R col that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k att , and detachment rate constants, k det , of colloids to the fracture surface have been measured for the fractured volcanics, and separate R col uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant retardation. Radionuclides irreversibly

  17. Parapapillary atrophy: histological gamma zone and delta zone.

    Directory of Open Access Journals (Sweden)

    Jost B Jonas

    Full Text Available BACKGROUND: To examine histomorphometrically the parapapillary region in human eyes. METHODOLOGY/PRINCIPAL FINDINGS: The histomorphometric study included 65 human globes (axial length:21-37 mm. On anterior-posterior histological sections, we measured the distance Bruch's membrane end (BME-optic nerve margin ("Gamma zone", BME-retinal pigment epithelium (RPE ("Beta zone", BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. "Delta zone" was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm was significantly (P = 0.01 larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28 associated with axial length. Beta zone was significantly (P = 0.004 larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm was associated with axial length (P50 µm diameter within gamma zone was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch's membrane without RPE was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.

  18. Using connectivity for measuring equity in transit provision

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Popoks, Dmitrijs; Prato, Carlo Giacomo

    2014-01-01

    . In addition, transit connectivity weighs the impedance components according to their relative importance to travelers. The assessment of equity was performed for the multi-modal transit system in the Greater Copenhagen Area, renowned for its transit-oriented finger-plan. The assessment method used a GIS...... representation of the network (i.e., service lines, timetables, metro stations, train stations, and bus stops), and transit assignment results (i.e., level-of-service times, passenger flows). The assessment method proved effective in calculating location-based and potential-accessibility measures and Gini...... coefficients of inequality in the Greater Copenhagen Area. Results show that the transit-oriented development contributes to spatial equity with high connectivity in densely populated zones, vertical equity with comparable connectivity in high income and low income zones, inter-generational equity with good...

  19. Empowerment Zones and Enterprise Districts - Volusia County Enterprise Zones

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Florida's Enterprise Zone Program encourages economic growth and investment in distressed areas by offering tax advantages and incentives to businesses that are...

  20. The Structural Phase Transition in Octaflournaphtalene

    DEFF Research Database (Denmark)

    Mackenzie, Gordon A.; Arthur, J. W.; Pawley, G. S.

    1977-01-01

    The phase transition in octafluoronaphthalene has been investigated by Raman scattering and neutron powder diffraction. The weight of the experimental evidence points to a unit cell doubling in the a direction, but with no change in space group symmetry. Lattice dynamics calculations support...... this evidence and indicate that the mechanism of the phase transition may well be the instability of a zone boundary acoustic mode of librational character. The structure of the low-temperature phase has been refined and the Raman spectra of the upper and lower phases are reported....

  1. The zone of alienation

    International Nuclear Information System (INIS)

    Nagorski, A.

    1996-01-01

    Ten years after the nuclear disaster, people still live and die in Chernobyl. Thousands of people continue to live and work there. Roughly 500 have moved back into their old homes inside the alienation zone. Fewer than half still alive. Medical researchers in the area insist that immune systems are weakened by doses of radiation far lower than previously thought. However, an European Union sponsored study concluded that Chernobyl's toll has been exaggerated. Thus, while 760 children in the contaminated area have developed thyroid cancer, only three have died as a result. Yet in and around Chernobyl, people carry on their lives and the Ukrainian Government says it can't afford to close the plant without billions of dollars in Western aid. ills

  2. Saturated Zone Colloid Transport

    Energy Technology Data Exchange (ETDEWEB)

    H. S. Viswanathan

    2004-10-07

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R{sub col} is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R{sub col} that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k{sub att}, and detachment rate constants, k{sub det}, of colloids to the fracture surface have been measured for the fractured volcanics, and separate R{sub col} uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant

  3. Optimal exploration target zones

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available prospective map are the weights-of-evidence (WofE) method logistic regression canonical favorability analysis neural networks evidential belief functions Optimal Exploration Target Zones Debba, Carranza, Stein, van der Meer Introduction to Remote.... . . ): FITNESS FUNCTION φWMSD+V(Sn) = λ N(A) ∑ −→x ∈A P(−→x ) ∣ ∣ ∣ ∣−→x −QSn( −→x ) ∣ ∣ ∣ ∣ +(1− λ)s2(OSn) , (2) where QSn( −→x ) is the location vector of an optimal exploration focal point in Sn nearest to −→x , and s2(OSn) is the variance...

  4. The zone of alienation

    Energy Technology Data Exchange (ETDEWEB)

    Nagorski, A.

    1996-04-23

    Ten years after the nuclear disaster, people still live and die in Chernobyl. Thousands of people continue to live and work there. Roughly 500 have moved back into their old homes inside the alienation zone. Fewer than half still alive. Medical researchers in the area insist that immune systems are weakened by doses of radiation far lower than previously thought. However, an European Union sponsored study concluded that Chernobyl`s toll has been exaggerated. Thus, while 760 children in the contaminated area have developed thyroid cancer, only three have died as a result. Yet in and around Chernobyl, people carry on their lives and the Ukrainian Government says it can`t afford to close the plant without billions of dollars in Western aid. ills.

  5. Street Prostitution Zones and Crime

    OpenAIRE

    Bisschop, Paul; Kastoryano, Stephen; van der Klaauw, Bas

    2015-01-01

    This paper studies the effects of introducing legal street prostitution zones on both registered and perceived crime. We exploit a unique setting in the Netherlands where legal street prostitution zones were opened in nine cities under different regulation systems. We provide evidence that the opening of these zones was not in response to changes in crime. Our difference-in-difference analysis using data on the largest 25 Dutch cities between 1994 and 2011 shows that opening a legal street pr...

  6. Thermal structure and geodynamics of subduction zones

    Science.gov (United States)

    Wada, Ikuko

    The thermal structure of subduction zones depends on the age-controlled thermal state of the subducting slab and mantle wedge flow. Observations indicate that the shallow part of the forearc mantle wedge is stagnant and the slab-mantle interface is weakened. In this dissertation, the role of the interface strength in controlling mantle wedge flow, thermal structure, and a wide range of subduction zone processes is investigated through two-dimensional finite-element modelling and a global synthesis of geological and geophysical observations. The model reveals that the strong temperature-dependence of the mantle strength always results in full slab-mantle decoupling along the weakened part of the interface and hence complete stagnation of the overlying mantle. The interface immediately downdip of the zone of decoupling is fully coupled, and the overlying mantle is driven to flow at a rate compatible with the subduction rate. The sharpness of the transition from decoupling to coupling depends on the rheology assumed and increases with the nonlinearity of the flow system. This bimodal behaviour of the wedge flow gives rise to a strong thermal contrast between the cold stagnant and hot flowing parts of the mantle wedge. The maximum depth of decoupling (MDD) thus dictates the thermal regime of the forearc. Observed surface heat flow patterns and petrologically and geochemically estimated mantle wedge temperatures beneath the volcanic arc require an MDD of 70--80 km in most, if not all, subduction zones regardless of their thermal regime of the slab. The common MDD of 70--80 km explains the observed systematic variations of the petrologic, seismological, and volcanic processes with the thermal state of the slab and thus explains the rich diversity of subduction zones in a unified fashion. Models for warm-slab subduction zones such as Cascadia and Nankai predict shallow dehydration of the slab beneath the cold stagnant part of the mantle wedge, which provides ample fluid

  7. Work Zone Data Collection Trailer

    Data.gov (United States)

    Federal Laboratory Consortium — The Work Zone Data Collection Trailer was designed and constructed to enhance data collection and analysis capabilities for the "Evaluating Roadway Construction Work...

  8. VT Data - Zoning 20170712, Westminster

    Data.gov (United States)

    Vermont Center for Geographic Information — Zoning districts, Westminster, Vermont. Overlay districts (Agricultural Land, Ridgeline Protection, and Historical Preservation) are in separate shapefiles. Data...

  9. Problems of Chernobyl Exclusion Zone

    International Nuclear Information System (INIS)

    Kholosha, V.Yi.

    2014-01-01

    The collection comprises the results of researches and design activity in the ChNPP exclusion zone, aimed at the development of technologies, equipment and devices for radioactive waste management and ChNPP accident clean-up, at studying the composition and structure of the Exclusion zone soil activity solid bearers, form transformation of the fission products of fuel fallout radionuclide composition in the ChNPP near zone, the spatial distribution of radionuclides and other radioecological issues.. Much attention is paid to medical and biological aspects of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the workers of the Exclusion zone

  10. Patrones geográficos de distribuci��n de árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile Geographic patterns of distribution of trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile

    Directory of Open Access Journals (Sweden)

    ERNESTO A. TENEB

    2004-03-01

    Full Text Available Uno de los principales objetivos de la biogeografía es determinar si las especies se distribuyen en el espacio en forma aleatoria o si existen grupos de especies con patrones de distribución comunes. En el presente estudio determinamos a través de técnicas cuantitativas si existen corotipos, es decir, grupos de especies con patrones de distribución común entre los árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile, Octava Región de Chile. Adicionalmente, evaluamos la relación entre el clima y la distribución de los diferentes grupos de árboles y arbustos de la Octava Región. El análisis de agrupamiento de especies permitió definir 24 corotipos significativos, de los cuales 18 responden significativamente con alguna variable ambiental analizada. La temperatura media anual, la temperatura media invernal y la temperatura media de verano resultaron ser las variables que mejor explican el patrón de distribución de la mayoría de los corotipos. Las tendencias geográficas de los corotipos y su relación con las variables ambientales fueron evaluadas mediante un análisis de ordenación. Los resultados señalan que los corotipos con distribución en la cordillera de los Andes se correlacionan con la temperatura de invierno en tanto que los corotipos con distribución costera se correlacionan con la mediterraneidad. Se discute respecto de la utilización de una nueva aproximación para el análisis fitogeográfico y de su utilidad en el estudio de la relación entre la vegetación y los factores ambientales que determinan su distribuciónOne main aim of biogeography is to determine if species are randomly distributed or if there exist groups of species with common distributional patterns known as chorotypes. In this study, we determined through quantitative techniques if there exists such chorotypes for trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile, Eigth

  11. Fuel conditioning facility zone-to-zone transfer administrative controls

    International Nuclear Information System (INIS)

    Pope, C. L.

    2000-01-01

    The administrative controls associated with transferring containers from one criticality hazard control zone to another in the Argonne National Laboratory (ANL) Fuel Conditioning Facility (FCF) are described. FCF, located at the ANL-West site near Idaho Falls, Idaho, is used to remotely process spent sodium bonded metallic fuel for disposition. The process involves nearly forty widely varying material forms and types, over fifty specific use container types, and over thirty distinct zones where work activities occur. During 1999, over five thousand transfers from one zone to another were conducted. Limits are placed on mass, material form and type, and container types for each zone. Ml material and containers are tracked using the Mass Tracking System (MTG). The MTG uses an Oracle database and numerous applications to manage the database. The database stores information specific to the process, including material composition and mass, container identification number and mass, transfer history, and the operators involved in each transfer. The process is controlled using written procedures which specify the zone, containers, and material involved in a task. Transferring a container from one zone to another is called a zone-to-zone transfer (ZZT). ZZTs consist of four distinct phases, select, request, identify, and completion

  12. Radial mixing of material in the asterodial zone

    International Nuclear Information System (INIS)

    Ruzmaikina, T.V.; Safronov, V.S.; Weidenschilling, S.J.

    1989-01-01

    The asteroid belt shows radial zoning of compositional structure. The most abundant types are successively S, C and P types from the inner to the outer parts of the main belt, and D type in the Trojan clouds. Boundaries between compositional zones are not sharp, but gradual transitions over scales ∼1 AU in semimajor axis. The authors examine processes for producing this structure before, during and after the accretion of asteroids. The initial structure is established by temperature and composition gradients in the turbulent solar nebula during the collapse of the presolar cloud. The radial scale of the zoning, comparable to the disk thickness, favors disk models with relatively low turbulent viscosity. Radial decay of solid bodies due to gas drag during settling to the central plane and planetesimal formation probably causes only a small degree of mixing, due to the systematic nature of drag-induced motions

  13. Zone memories and pseudorandom addressing

    International Nuclear Information System (INIS)

    Marino, D.; Mirizzi, N.; Stella, R.; Visaggio, G.

    1975-01-01

    A quantitative comparison between zone memories, pseudorandom addressed memories and an alternative special purpose memory (spread zone memory) in which the distance between any two transformed descriptors, at first adjacent, is independent of the descriptors pair and results the maximum one is presented. This memory has not been particularly considered at present in spite of its efficiency and its simple implementation

  14. Environmental Zoning: Some methodological implications

    NARCIS (Netherlands)

    Ike, Paul; Voogd, Henk

    1991-01-01

    The purpose of this article is to discuss some methodological problems of environmental zoning. The principle of environmental zoning will be elaborated. In addition an overview is given of a number of approaches that have been followed in practice to arrive at an integral judgement. Finally some

  15. Instrumentation for coastal zone management

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.

    stream_size 11 stream_content_type text/plain stream_name Trg_Course_Coast_Zone_Manage_1993_91.pdf.txt stream_source_info Trg_Course_Coast_Zone_Manage_1993_91.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  16. Management of coastal zone vegetation

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.

    stream_size 14 stream_content_type text/plain stream_name Trg_Course_Coast_Zone_Manage_1993_22.pdf.txt stream_source_info Trg_Course_Coast_Zone_Manage_1993_22.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  17. Growth with Time Zone Differences

    OpenAIRE

    Toru Kikuchi; Sugata Marjit

    2010-01-01

    We propose a two-country growth model of intermediate business-services trade that captures the role of time zone differences. It is shown that a time-saving improvement in intermediate business-services trade involving production in different time zones can have a permanent impact on productivity.

  18. Propagation of normal zones in composite superconductors

    International Nuclear Information System (INIS)

    Dresner, L.

    1976-08-01

    This paper describes calculations of propagation velocities of normal zones in composite superconductors. Full accounting is made for (1) current sharing, (2) the variation with temperature of the thermal conductivity of the copper matrix, and the specific heats of the matrix and the superconductor, and (3) the variation with temperature of the steady-state heat transfer at a copper-helium interface in the nucleate-boiling, transition, and film-boiling ranges. The theory, which contains no adjustable parameters, is compared with experiments on bare (uninsulated) conductors. Agreement is not good. It is concluded that the effects of transient heat transfer may need to be included in the theory to improve agreement with experiment

  19. Habitable zone dependence on stellar parameter uncertainties

    International Nuclear Information System (INIS)

    Kane, Stephen R.

    2014-01-01

    An important property of exoplanetary systems is the extent of the Habitable Zone (HZ), defined as that region where water can exist in a liquid state on the surface of a planet with sufficient atmospheric pressure. Both ground- and space-based observations have revealed a plethora of confirmed exoplanets and exoplanetary candidates, most notably from the Kepler mission using the transit detection technique. Many of these detected planets lie within the predicted HZ of their host star. However, as is the case with the derived properties of the planets themselves, the HZ boundaries depend on how well we understand the host star. Here we quantify the uncertainties of HZ boundaries on the parameter uncertainties of the host star. We examine the distribution of stellar parameter uncertainties from confirmed exoplanet hosts and Kepler candidate hosts and translate these into HZ boundary uncertainties. We apply this to several known systems with an HZ planet to determine the uncertainty in their HZ status.

  20. Habitable zone dependence on stellar parameter uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Kane, Stephen R., E-mail: skane@sfsu.edu [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States)

    2014-02-20

    An important property of exoplanetary systems is the extent of the Habitable Zone (HZ), defined as that region where water can exist in a liquid state on the surface of a planet with sufficient atmospheric pressure. Both ground- and space-based observations have revealed a plethora of confirmed exoplanets and exoplanetary candidates, most notably from the Kepler mission using the transit detection technique. Many of these detected planets lie within the predicted HZ of their host star. However, as is the case with the derived properties of the planets themselves, the HZ boundaries depend on how well we understand the host star. Here we quantify the uncertainties of HZ boundaries on the parameter uncertainties of the host star. We examine the distribution of stellar parameter uncertainties from confirmed exoplanet hosts and Kepler candidate hosts and translate these into HZ boundary uncertainties. We apply this to several known systems with an HZ planet to determine the uncertainty in their HZ status.

  1. Active-to-Passive Environmental Cleanup Transition Strategies - 13220

    International Nuclear Information System (INIS)

    Gaughan, Thomas F.; Aylward, Robert S.; Denham, Miles E.; Looney, Brian B.; Whitaker, Wade C.; Mills, Gary L.

    2013-01-01

    The Savannah River Site uses a graded approach to environmental cleanup. The selection of groundwater and vadose zone remediation technologies for a specific contamination area is based on the size, contaminant type, contaminant concentration, and configuration of the plume. These attributes are the result of the nature and mass of the source of contamination and the subsurface characteristics in the area of the plume. Many large plumes consist of several zones that are most efficiently addressed with separate complementary corrective action/remedial technologies. The highest concentrations of contaminants are found in the source zone. The most robust, high mass removal technologies are often best suited for remediation of the source zone. In the primary plume zone, active remedies, such as pump-and-treat, may be necessary to remove contaminants and exert hydraulic control of the plume. In the dilute fringe zone, contaminants are generally lower in concentration and can often be treated with passive techniques. A key determination in achieving an acceptable and cost-effective end state for a given waste unit is when to transition from an active treatment system to a more passive or natural approach (e.g., monitored natural attenuation or enhanced attenuation). This paper will discuss the considerations for such a transition as well as provide examples of successful transitions at the Savannah River Site. (authors)

  2. Evidence for continuum absorption above the quiet sun transition region

    International Nuclear Information System (INIS)

    Schmahl, E.J.; Orrall, F.Q.

    1979-01-01

    We report new evidence for continuum absorption in the solar transition zone in EUV spectra obtained from OSO 4, OSO 6, ATM, and full Sun measurements. This absorption shortward of 912 A is manifest everywhere on the Sun's disk. It is present within network cells and boundaries of the quiet Sun, in coronal holes, in active regions, above the limb, and in solar prominences. Models of the upper chromosphere and the transition zone must be modified to include an admixture of neutral hydrogen (or possibly singly ionized helium) with the hotter plasma

  3. The Supergalactic Habitable Zone

    Science.gov (United States)

    Mason, Paul

    2018-01-01

    Habitability in the local universe is examined. Constrained by metal abundance and exposure to sterilizing events, life as we know it requires significantly long periods of stable environmental conditions. Planets within galaxies undergoing major mergers, active AGN, starburst episodes, and merging black holes pose serious threats to long-term habitability. Importantly, the development of several layers of protection from high-energy particles such as a thick atmosphere, a strong planetary magnetic field, an astrosphere, and a galactic magnetic field is of great benefit. Factors such as star type and activity, planet type and composition, the location of a planet within its host galaxy, and even the location within a supercluster of galaxies can affect the potential habitability of planets. We discuss the concept of the Supergalactic Habitable Zone introduced by Mason and Biermann in terms of habitability in the local universe and find that galaxies near the center of the Virgo cluster, for example, have a much lower probability for the development of life as we know it as compared to locations in the Milky Way.

  4. Coastal Zone Color Scanner

    Science.gov (United States)

    Johnson, B.

    1988-01-01

    The Coastal Zone Color Scanner (CZCS) spacecraft ocean color instrument is capable of measuring and mapping global ocean surface chlorophyll concentration. It is a scanning radiometer with multiband capability. With new electronics and some mechanical, and optical re-work, it probably can be made flight worthy. Some additional components of a second flight model are also available. An engineering study and further tests are necessary to determine exactly what effort is required to properly prepare the instrument for spaceflight and the nature of interfaces to prospective spacecraft. The CZCS provides operational instrument capability for monitoring of ocean productivity and currents. It could be a simple, low cost alternative to developing new instruments for ocean color imaging. Researchers have determined that with global ocean color data they can: specify quantitatively the role of oceans in the global carbon cycle and other major biogeochemical cycles; determine the magnitude and variability of annual primary production by marine phytoplankton on a global scale; understand the fate of fluvial nutrients and their possible affect on carbon budgets; elucidate the coupling mechanism between upwelling and large scale patterns in ocean basins; answer questions concerning the large scale distribution and timing of spring blooms in the global ocean; acquire a better understanding of the processes associated with mixing along the edge of eddies, coastal currents, western boundary currents, etc., and acquire global data on marine optical properties.

  5. Emergency planning zone reduction

    International Nuclear Information System (INIS)

    Edwards, C.

    2002-01-01

    This paper describes the process used by a large industrial Department of Energy (DOE) site to communicate changing hazards to its stakeholders and install the confidence necessary to implement the resulting emergency planning changes. Over the last decade as the sites missions have shifted from full-scale production to a greater emphasis on environmental restoration and waste management, the off-site threat from its operations has substantially decreased. The challenge was to clearly communicate the reduced hazards, install confidence in the technical analysis that documented the hazard reduction, and obtain stakeholder buy-in on the path forward to change the emergency management program. The most significant change to the emergency management program was the proposed reduction of the sites Emergency Planning Zone (EPZ). As the EPZ is defined as an area for which planning is needed to protect the public in the event of an accident, the process became politically challenging. An overview of how the site initially approached this problem and then learned to more substantially involve the state and local emergency preparedness agencies and the local Citizens Advisory Board will be presented. (author)

  6. Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay

    Directory of Open Access Journals (Sweden)

    Faming Huang

    2018-05-01

    Full Text Available Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A, while land change was fastest during the second time interval 2002–2009 in a separate terrestrial area within coastal zone (zone B. Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban

  7. Numerical simulation of transitional flow on a wind turbine airfoil with RANS-based transition model

    Science.gov (United States)

    Zhang, Ye; Sun, Zhengzhong; van Zuijlen, Alexander; van Bussel, Gerard

    2017-09-01

    This paper presents a numerical investigation of transitional flow on the wind turbine airfoil DU91-W2-250 with chord-based Reynolds number Rec = 1.0 × 106. The Reynolds-averaged Navier-Stokes based transition model using laminar kinetic energy concept, namely the k - kL - ω model, is employed to resolve the boundary layer transition. Some ambiguities for this model are discussed and it is further implemented into OpenFOAM-2.1.1. The k - kL - ω model is first validated through the chosen wind turbine airfoil at the angle of attack (AoA) of 6.24° against wind tunnel measurement, where lift and drag coefficients, surface pressure distribution and transition location are compared. In order to reveal the transitional flow on the airfoil, the mean boundary layer profiles in three zones, namely the laminar, transitional and fully turbulent regimes, are investigated. Observation of flow at the transition location identifies the laminar separation bubble. The AoA effect on boundary layer transition over wind turbine airfoil is also studied. Increasing the AoA from -3° to 10°, the laminar separation bubble moves upstream and reduces in size, which is in close agreement with wind tunnel measurement.

  8. 75 FR 36288 - Amended Safety Zone and Regulated Navigation Area, Chicago Sanitary and Ship Canal, Romeoville, IL

    Science.gov (United States)

    2010-06-25

    ...The Coast Guard is revising its safety zone and Regulated Navigation Area (RNA) on the Chicago Sanitary and Ship Canal (CSSC) near Romeoville, IL. This revised temporary interim rule reduces the areas covered by the safety zone and RNA, and places additional restrictions on vessels that may transit the RNA.

  9. 77 FR 37318 - Eighth Coast Guard District Annual Safety Zones; Sound of Independence; Santa Rosa Sound; Fort...

    Science.gov (United States)

    2012-06-21

    ...-AA00 Eighth Coast Guard District Annual Safety Zones; Sound of Independence; Santa Rosa Sound; Fort... Coast Guard will enforce a Safety Zone for the Sound of Independence event in the Santa Rosa Sound, Fort... during the Sound of Independence. During the enforcement period, entry into, transiting or anchoring in...

  10. Structure and properties of melt-spun high acrylonitrile copolymer fibers via continuous zone-drawing and zone-annealing processes

    International Nuclear Information System (INIS)

    Wu Zongquan; Zhang Anqiu; Percec, Simona; Jin Shi; Jing, Alexander J.; Ge, Jason J.; Cheng, Stephen Z.D.

    2003-01-01

    Continuous zone-drawing and zone-annealing processes have been utilized to probe improvements in mechanical performance of melt-spun high acrylonitrile copolymer fibers (AMLON TM ). The as-spun fibers were zone-drawn at different ratios in a narrow temperature range of 100-105 deg. C and then zone-annealed. As a result of these processes, the fibers show substantial increases in tensile strength and tensile modulus (about three times) and significant improvements in elongation-at-break (about two times) after zone annealing. The thermal transition behavior, dimensional stability and dynamic relaxation properties of the as-spun, zone-drawn and zone-annealed fibers have been studied using differential scanning calorimetry, thermal mechanical and dynamic mechanical experiments. Their mechanical and thermal property changes after the zone-drawing and zone-annealing processes can be associated with the microscopic structural evolution including crystallinity, crystal orientation and apparent crystallite size detected by wide angle X-ray diffraction experiments

  11. 77 FR 64718 - Safety Zone; Steam Ship Col. James M. Schoonmaker Relocation Project, Maumee River, Toledo, OH

    Science.gov (United States)

    2012-10-23

    ...The Coast Guard is establishing a temporary Safety Zone on the waters of Maumee River, Toledo, Ohio, in support of the relocation of S/S Col. James M. Schoonmaker (hereinafter referred to as `the Schoonmaker'). This temporary safety zone will encompass all waters of the Maumee River within a 100 yard radius of the Schoonmaker as it makes its transit from International Park to Skyway Marina. This temporary Safety Zone is necessary to protect persons operating around the area.

  12. Oscillation of an anuran hybrid zone: morphological evidence spanning 50 years.

    Directory of Open Access Journals (Sweden)

    Jean-Sébastien Roy

    Full Text Available The hybrid zone between the primarily forest-dwelling American toad, Anaxyrus americanus, and the prairie-adapted Canadian toad, A. hemiophrys, in southeastern Manitoba is known to have shifted its position during the past 50 years. Hybrid zones are areas of interbreeding between species and their movement across a landscape should reflect their underlying dynamics and environmental change. However, empirical demonstrations of hybrid zone movements over long periods of time are rare. This hybrid zone is dominated by individuals of intermediate morphology and genetic composition. We sought to determine if it had continued to move and if that movement was associated with shifts in habitat, as predicted.We used variation in the toads' most diagnostic morphological feature, the separation between their interorbital cranial crests, to determine the geographic position of the hybrid zone center at four times between 1960 and 2009 using maximum likelihood methods. The hybrid zone center moved west by 38 km over 19 years and then east again by 10 km over the succeeding 29 years. The position of the hybrid zone did not track either the direction or the magnitude of movement of the forest-prairie habitat transition over the same time period.This is the first reported evidence of oscillation in the position of a hybrid zone. The back and forth movement indicates that neither species maintains a selective advantage over the other in the long term. However, the movement of the hybrid zone was not bounded by the breadth of the habitat transition. Its oscillation suggests that the hybrid zone is better described as being elastically tethered to the habitat transition.

  13. Electronic topological transitions in Zn under compression

    Science.gov (United States)

    Kechin, Vladimir V.

    2001-01-01

    The electronic structure of hcp Zn under pressure up to 10 GPa has been calculated self-consistently by means of the scalar relativistic tight-binding linear muffin-tin orbital method. The calculations show that three electronic topological transitions (ETT's) occur in Zn when the c/a axial ratio diminishes under compression. One transition occurs at c/a~=1.82 when the ``needles'' appear around the symmetry point K of the Brillouin zone. The other two transitions occur at c/a~=3, when the ``butterfly'' and ``cigar'' appear simultaneously both around the L point. It has been shown that these ETT's are responsible for a number of anomalies observed in Zn at compression.

  14. Mechanical properties of fracture zones

    International Nuclear Information System (INIS)

    Leijon, B.

    1993-05-01

    Available data on mechanical characteristics of fracture zones are compiled and discussed. The aim is to improve the basis for adequate representation of fracture zones in geomechanical models. The sources of data researched are primarily borehole investigations and case studies in rock engineering, involving observations of fracture zones subjected to artificial load change. Boreholes only yield local information about the components of fracture zones, i.e. intact rock, fractures and various low-strength materials. Difficulties are therefore encountered in evaluating morphological and mechanical properties of fracture zones from borehole data. Although often thought of as macroscopically planar features, available field data consistently show that fracture zones are characterized by geometrical irregularities such as thickness variations, surface undulation and jogs. These irregularities prevail on all scales. As a result, fracture zones are on all scales characterized by large, in-plane variation of strength- and deformational properties. This has important mechanical consequences in terms of non-uniform stress transfer and complex mechanisms of shear deformation. Field evidence for these findings, in particular results from the underground research laboratory in Canada and from studies of induced fault slip in deep mines, is summarized and discussed. 79 refs

  15. Problems of Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    1996-01-01

    The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health labour conditions and incidence of the people involved

  16. Problems of Chornobyl Exclusion Zone

    International Nuclear Information System (INIS)

    Kashparov, V.A.

    2009-01-01

    The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved.

  17. 75 FR 50700 - Quarterly Listings; Safety Zones, Security Zones, Special Local Regulations, and Drawbridge...

    Science.gov (United States)

    2010-08-17

    ...] Quarterly Listings; Safety Zones, Security Zones, Special Local Regulations, and Drawbridge Operation... notice lists temporary safety zones, security zones, special local regulations, and drawbridge operation... responsive to the safety and security needs within their jurisdiction; therefore, District Commanders and...

  18. Seismic cycle feedbacks in a mid-crustal shear zone

    Science.gov (United States)

    Melosh, Benjamin L.; Rowe, Christie D.; Gerbi, Christopher; Smit, Louis; Macey, Paul

    2018-07-01

    Mid-crustal fault rheology is controlled by alternating brittle and plastic deformation mechanisms, which cause feedback cycles that influence earthquake behavior. Detailed mapping and microstructural observations in the Pofadder Shear Zone (Namibia and South Africa) reveal a lithologically heterogeneous shear zone core with quartz-rich mylonites and ultramylonites, plastically overprinted pseudotachylyte and active shear folds. We present evidence for a positive feedback cycle in which coseismic grain size reduction facilitates active shear folding by enhancing competency contrasts and promoting crystal plastic flow. Shear folding strengthens a portion of a shear zone by limb rotation, focusing deformation and promoting plastic flow or brittle slip in resulting areas of localized high stress. Using quartz paleopiezometry, we estimate strain and slip rates consistent with other studies of exhumed shear zones and modern plate boundary faults, helping establish the Pofadder Shear Zone as an ancient analogue to modern, continental-scale, strike-slip faults. This feedback cycle influences seismicity patterns at the scale of study (10s of meters) and possibly larger scales as well, and contributes to bulk strengthening of the brittle-plastic transition on modern plate boundary faults.

  19. VT Data - Zoning Stream Buffers 20081014, Hartford

    Data.gov (United States)

    Vermont Center for Geographic Information — OVERLAY DISTRICT. Models a municipality’s zoning zones and related information. Final boundary determinations must be obtained from the town Zoning Administrator....

  20. Stagnation zone formation on the axis of a closed vortex flow

    DEFF Research Database (Denmark)

    Naumov, I. V.; Okulov, Valery; Mikkelsen, Robert Flemming

    2014-01-01

    The features of developing a counterflow zone (bubble-mode vortex breakdown or vortex explosion) at the center of an intensively swirled flow produced in a liquid-filled cylindrical container with a rotating endwall have been studied. The observation showed that the scenario of developing a bubbl......-mode breakdown zone with generation of counterflow is the same for cylinders with low or high aspect ratio, and it remains independent of stationary-nonstationary transition boundary for the main vortex flow....

  1. Hydrodynamic effects of macrophyte microtopography: spatial consequences of interspecific benthic transitions

    NARCIS (Netherlands)

    Lara, M.; Bouma, T.J.; Peralta, G.; van Soelen, J.; Pérez-Llorens, J.L.

    2016-01-01

    Rhizophytic green algae of the genus Caulerpa are potential competitors with seagrass-dominated habitats. At Cadiz Bay Natural Park, Caulerpa prolifera and the seagrass Cymodocea nodosa co-occur in overlapping patches, which may be considered as transition zones. In these zones, changes in

  2. Biodiesel Mass Transit Demonstration

    Science.gov (United States)

    2010-04-01

    The Biodiesel Mass Transit Demonstration report is intended for mass transit decision makers and fleet managers considering biodiesel use. This is the final report for the demonstration project implemented by the National Biodiesel Board under a gran...

  3. Public Transit Stations

    Data.gov (United States)

    Department of Homeland Security — fixed rail transit stations within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico. The modes of transit that are serviced...

  4. NEPR Geographic Zone Map 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This geographic zone map was created by interpreting satellite and aerial imagery, seafloor topography (bathymetry model), and the new NEPR Benthic Habitat Map...

  5. Deciduous Forest Zone of Ghana

    African Journals Online (AJOL)

    carbon, nitrogen and phosphorus contents, soil reaction and base saturation with highest values in the topsoil due to the .... These soils occur extensively in the. Zone ... tion with 6M sulphuric acid. .... which will lead to removal of topsoil litter,.

  6. VT Data - Zoning 20130305, Dover

    Data.gov (United States)

    Vermont Center for Geographic Information — This file, along with two others, was created to produce a new, official zoning map series for the Town of Dover, Vermont in 2007. This file represents the base...

  7. Offshore Wind Technology Depth Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coastal bathymetric depth, measured in meters at depth values of: -30, -60, -900 Shallow Zone (0-30m): Technology has been demonstrated on a commercial scale at...

  8. Work zone and operation enhancements.

    Science.gov (United States)

    2010-02-01

    Oregon Department of Transportation contractors are required to implement Traffic Control Plans (TCPs) to protect and direct traffic through work zones. The design and implementation of TCPs have shown variation from project-to-project across the Sta...

  9. VT Data - Zoning 20170407, Burlington

    Data.gov (United States)

    Vermont Center for Geographic Information — For a detailed description of the zoning districts referenced in this data, please refer to the City of Burlington, Vermont's webpage. Please be sure to review all...

  10. ShoreZone Survey Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a point file showing GPS trackline data collected during a ShoreZone aerial imaging survey. This flight trackline is recorded at 1-second intervals...

  11. Embodied Archives as Contact Zones

    Directory of Open Access Journals (Sweden)

    Judit Vidiella

    2015-02-01

    Full Text Available This article proposes a reflection about affective politics from locating some theoretical and conceptual genealogies like «emotion», «affection», «zones of contact»…, that understand them as action and force fields. These contributions allow us to rethink the relation of affects with politics and strategies of archive linked to performance, and understood as zones of friction, collision, circulation and contact: performative writing, repertoire, memes…

  12. Quantum phase transitions

    International Nuclear Information System (INIS)

    Sachdev, S.

    1999-01-01

    Phase transitions are normally associated with changes of temperature but a new type of transition - caused by quantum fluctuations near absolute zero - is possible, and can tell us more about the properties of a wide range of systems in condensed-matter physics. Nature abounds with phase transitions. The boiling and freezing of water are everyday examples of phase transitions, as are more exotic processes such as superconductivity and superfluidity. The universe itself is thought to have passed through several phase transitions as the high-temperature plasma formed by the big bang cooled to form the world as we know it today. Phase transitions are traditionally classified as first or second order. In first-order transitions the two phases co-exist at the transition temperature - e.g. ice and water at 0 deg., or water and steam at 100 deg. In second-order transitions the two phases do not co-exist. In the last decade, attention has focused on phase transitions that are qualitatively different from the examples noted above: these are quantum phase transitions and they occur only at the absolute zero of temperature. The transition takes place at the ''quantum critical'' value of some other parameter such as pressure, composition or magnetic field strength. A quantum phase transition takes place when co-operative ordering of the system disappears, but this loss of order is driven solely by the quantum fluctuations demanded by Heisenberg's uncertainty principle. The physical properties of these quantum fluctuations are quite distinct from those of the thermal fluctuations responsible for traditional, finite-temperature phase transitions. In particular, the quantum system is described by a complex-valued wavefunction, and the dynamics of its phase near the quantum critical point requires novel theories that have no analogue in the traditional framework of phase transitions. In this article the author describes the history of quantum phase transitions. (UK)

  13. Cosmological phase transitions

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1993-10-01

    If modern ideas about the role of spontaneous symmetry breaking in fundamental physics are correct, then the Universe should have undergone a series of phase transitions early in its history. The study of cosmological phase transitions has become an important aspect of early-Universe cosmology. In this lecture I review some very recent work on three aspects of phase transitions: the electroweak transition, texture, and axions

  14. Women in Chernobyl Exclusion Zone

    International Nuclear Information System (INIS)

    Balashevska, Y.; Kireev, S.; Navalikhin, V.

    2015-01-01

    Today, 29 years after the Chernobyl accident, the Exclusion Zone still remains an areal unsealed radiation source of around 2600 km"2. It is not just a gigantic radioactive waste storage facility (the amount of radioactive waste accumulated within the Zone, except for the Shelter, is estimated at about 2.8 million m"3), but also a unique research and engineering platform for biologists, radiologists, chemists and physicists. Taking into account the amount of the radionuclides released during the accident, it becomes quite understood that the radiological environment in the Exclusion Zone is far from favorable. However, among the Exclusion Zone personnel who numbers 5000, there are female workers. The poster represents the results of the research performed among the female employees of the largest enterprise of the Exclusion Zone, “Chornobyl Spetskombinat”. The survey was performed with the view to knowing what makes women work in the most radioactively contaminated area in Europe, and what their role is, to revealing their fears and hopes, and to estimating the chances of the brave women of Chernobyl Exclusion Zone to succeed in their careers. (author)

  15. Modeling for transition management

    NARCIS (Netherlands)

    Chappin, E.J.L.; Dijkema, G.P.J.

    2015-01-01

    A framework for the modeling and simulation of transitions is presented. A transition, “substantial change in the state of a socio-technical system”, typically unfolds over a long timespan. We therefore suggest to use simulation to inform transition managers on the effect of their decisions.

  16. Modeling for Transition Management

    NARCIS (Netherlands)

    Chappin, Emile J L; Dijkema, Gerard P.J.

    2015-01-01

    A framework for the modeling and simulation of transitions is presented. A transition, “substantial change in the state of a socio-technical system”, typically unfolds over a long timespan. We therefore suggest to use simulation to inform transition managers on the effect of their decisions.

  17. Microwave stability at transition

    International Nuclear Information System (INIS)

    Holt, J.A.; Colestock, P.L.

    1995-05-01

    The question of microwave stability at transition is revisited using a Vlasov approach retaining higher order terms in the particle dynamics near the transition energy. A dispersion relation is derived which can be solved numerically for the complex frequency in terms of the longitudinal impedance and other beam parameters. Stability near transition is examined and compared with simulation results

  18. Transit manager's handbook.

    Science.gov (United States)

    2011-09-01

    This handbook provides an overview of public transit in Iowa and how to do business with the Iowa Department of Transportation (Iowa DOT) Office of Public Transit (OPT). It is intended to be a tool to assist transit managers navigate through the many...

  19. Transit labor relations guide

    Science.gov (United States)

    2001-09-01

    This report is designed as a guide for those involved in labor relations in the transit industry. It begins with a history of transit labor relations. The economic, political, and legal environment of transit relations is then discussed. A section fo...

  20. Transition: Preschool to Kindergarten

    Science.gov (United States)

    Arizona Department of Education, 2007

    2007-01-01

    Transition is movement or change without interruption. It should be a smooth flow from one place or condition to another. While the transition plan for a student receiving special education services is designed to prepare him or her for life after high school, transition can start when a child enters preschool. The second of six distinct stages of…

  1. Mechanical modelling of the Singoe deformation zone. Site descriptive modelling Forsmark stage 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Maersk Hansen, Lars; Fredriksson, Anders; Bergkvist, Lars; Markstroem, Ingemar; Elfstroem, Mats [Golder Associates AB (Sweden)

    2007-02-15

    This project aims at demonstrating the theoretical approach developed by SKB for determination of mechanical properties of large deformation zones, in particular the Singoe deformation zone. Up to now, only bedrock and minor deformation zones have been characterized by means of this methodology, which has been modified for this project. The Singoe deformation zone is taken as a reference object to get a more comprehensive picture of the structure, which could be incorporated in a future version of the SDM of Forsmark. Furthermore, the Singoe Zone has been chosen because of available data from four tunnels. Scope of work has included compilation and analysis of geological information from site investigations and documentation of existing tunnels. Results have been analyzed and demonstrated by means of RVS-visualization. Numerical modelling has been used to obtain mechanical properties. Numerical modelling has also been carried out in order to verify the results by comparison of calculated and measured deformations. Compilation of various structures in the four tunnels coincides largely with a magnetic anomaly and also with the estimated width. Based on the study it is clear that the Singoe deformation zone has a heterogeneous nature. The number of fracture zones associated with the deformation zone varies on either side of the zone, as does the transition zone between host rock and the Singoe zone. The overall impression from the study is that the results demonstrate that the methodology used for simulating of equivalent mechanical properties is an applicable and adequate method, also in case of large deformation zones. Typical rock mechanical parameters of the Singoe deformations that can be used in the regional stress model considering the zone to be a single fracture are: 200 MPa/m in normal stiffness, 10-15 MPa/m in shear stiffness, 0.4 MPa in cohesion and 31.5 degrees in friction angle.

  2. Mechanical modelling of the Singoe deformation zone. Site descriptive modelling Forsmark stage 2.1

    International Nuclear Information System (INIS)

    Glamheden, Rune; Maersk Hansen, Lars; Fredriksson, Anders; Bergkvist, Lars; Markstroem, Ingemar; Elfstroem, Mats

    2007-02-01

    This project aims at demonstrating the theoretical approach developed by SKB for determination of mechanical properties of large deformation zones, in particular the Singoe deformation zone. Up to now, only bedrock and minor deformation zones have been characterized by means of this methodology, which has been modified for this project. The Singoe deformation zone is taken as a reference object to get a more comprehensive picture of the structure, which could be incorporated in a future version of the SDM of Forsmark. Furthermore, the Singoe Zone has been chosen because of available data from four tunnels. Scope of work has included compilation and analysis of geological information from site investigations and documentation of existing tunnels. Results have been analyzed and demonstrated by means of RVS-visualization. Numerical modelling has been used to obtain mechanical properties. Numerical modelling has also been carried out in order to verify the results by comparison of calculated and measured deformations. Compilation of various structures in the four tunnels coincides largely with a magnetic anomaly and also with the estimated width. Based on the study it is clear that the Singoe deformation zone has a heterogeneous nature. The number of fracture zones associated with the deformation zone varies on either side of the zone, as does the transition zone between host rock and the Singoe zone. The overall impression from the study is that the results demonstrate that the methodology used for simulating of equivalent mechanical properties is an applicable and adequate method, also in case of large deformation zones. Typical rock mechanical parameters of the Singoe deformations that can be used in the regional stress model considering the zone to be a single fracture are: 200 MPa/m in normal stiffness, 10-15 MPa/m in shear stiffness, 0.4 MPa in cohesion and 31.5 degrees in friction angle

  3. The Sorong Fault Zone, Indonesia: Mapping a Fault Zone Offshore

    Science.gov (United States)

    Melia, S.; Hall, R.

    2017-12-01

    The Sorong Fault Zone is a left-lateral strike-slip fault zone in eastern Indonesia, extending westwards from the Bird's Head peninsula of West Papua towards Sulawesi. It is the result of interactions between the Pacific, Caroline, Philippine Sea, and Australian Plates and much of it is offshore. Previous research on the fault zone has been limited by the low resolution of available data offshore, leading to debates over the extent, location, and timing of movements, and the tectonic evolution of eastern Indonesia. Different studies have shown it north of the Sula Islands, truncated south of Halmahera, continuing to Sulawesi, or splaying into a horsetail fan of smaller faults. Recently acquired high resolution multibeam bathymetry of the seafloor (with a resolution of 15-25 meters), and 2D seismic lines, provide the opportunity to trace the fault offshore. The position of different strands can be identified. On land, SRTM topography shows that in the northern Bird's Head the fault zone is characterised by closely spaced E-W trending faults. NW of the Bird's Head offshore there is a fold and thrust belt which terminates some strands. To the west of the Bird's Head offshore the fault zone diverges into multiple strands trending ENE-WSW. Regions of Riedel shearing are evident west of the Bird's Head, indicating sinistral strike-slip motion. Further west, the ENE-WSW trending faults turn to an E-W trend and there are at least three fault zones situated immediately south of Halmahera, north of the Sula Islands, and between the islands of Sanana and Mangole where the fault system terminates in horsetail strands. South of the Sula islands some former normal faults at the continent-ocean boundary with the North Banda Sea are being reactivated as strike-slip faults. The fault zone does not currently reach Sulawesi. The new fault map differs from previous interpretations concerning the location, age and significance of different parts of the Sorong Fault Zone. Kinematic

  4. Kinetic synergistic transitions in the Ostwald ripening processes

    Science.gov (United States)

    Sachkov, I. N.; Turygina, V. F.; Dolganov, A. N.

    2018-01-01

    There is proposed approach to mathematical description of the kinetic transitions in Ostwald ripening processes of volatile substance in nonuniformly heated porous materials. It is based upon the finite element method. There are implemented computer software. The main feature of the software is to calculate evaporation and condensation fluxes on the walls of a nonuniformly heated cylindrical capillary. Kinetic transitions are detected for three modes of volatile substances migration which are different by condensation zones location. There are controlling dimensionless parameters of the kinetic transition which are revealed during research. There is phase diagram of the Ostwald ripening process modes realization.

  5. Flow Topology Transition via Global Bifurcation in Thermally Driven Turbulence

    Science.gov (United States)

    Xie, Yi-Chao; Ding, Guang-Yu; Xia, Ke-Qing

    2018-05-01

    We report an experimental observation of a flow topology transition via global bifurcation in a turbulent Rayleigh-Bénard convection. This transition corresponds to a spontaneous symmetry breaking with the flow becomes more turbulent. Simultaneous measurements of the large-scale flow (LSF) structure and the heat transport show that the LSF bifurcates from a high heat transport efficiency quadrupole state to a less symmetric dipole state with a lower heat transport efficiency. In the transition zone, the system switches spontaneously and stochastically between the two long-lived metastable states.

  6. Influence of shock induced polymorphic transition on penetration in steel

    International Nuclear Information System (INIS)

    Hereil, P.L.; Fanget, A.

    1994-01-01

    The effects of polymorphic transition for the impact of a 27NCD10 steel projectile on a 27NCD10 steel target at 1280 m/s is presented. Comparisons between results of 2D numerical calculations performed with and without polymorphic transition show the influence of this phenomenon on stress distribution and tension zones in the target and in the projectile. Good agreement between experimental and calculated free surface velocity profiles is obtained with polymorphic transition and damage models taken into account. (orig.)

  7. Primavera Ring. Management perspectives on La Primavera forest buffer zone, from the cultural landscapes approach

    Directory of Open Access Journals (Sweden)

    Pedro Alcocer Santos

    2016-06-01

    Full Text Available The current article intends to high light the need to implement a buffer zone for La Primavera Forest,  Biosphere reserve MaB UNESCO in Guadalajara, Jalisco. The criteria to develop this transition zone is based on understanding this territory as a Cultural Landscape. Seeking common ground between Biosphere Reserves and Cultural Landscapes criteria to organize the management and development of the buffer zone. To understand the opponents of city development and forest preservation as complementary elements, a paradigm shift is needed. This is an applied research from the ITESO, and it is structured as a Think Tank that involves society, government and academy.

  8. Transition Theory – Sustainable Transition of Socio-Technical Systems

    DEFF Research Database (Denmark)

    Søndergård, Bent; Holm, Jesper; Stauning, Inger

    2015-01-01

    Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction......Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction...

  9. Surface modification by preparation of buffer zone in glow-discharge plasma

    International Nuclear Information System (INIS)

    Cho, D.L.

    1986-01-01

    Reactive species, energetic particles, and uv radiation in the plasma created by a glow discharge strongly interact with solid surfaces under the influence of the plasma. As a result of the strong interaction, various physical and chemical reactions, unique and advantageous for the surface modification of solid materials, occur on the solid surfaces. The surface modification is carried out through formation of a thin buffering layer on the solid surface. The preparation of a buffer zone on solid surfaces for surface modification is described. Two kinds of a buffer zone are prepared by plasma polymerization, or simultaneous sputter deposition of electrode material with plasma polymerization: a transitional buffer zone and a graded buffer zone. Important factors for preparation of the buffer zone (pre-conditioning of a substrate surface, thin-film deposition, post-treatment of the film, magnetron discharge, energy input, geometry of a substrate and a plasma) are discussed

  10. Gifts from Exoplanetary Transits

    Science.gov (United States)

    Narita, Norio

    2009-08-01

    The discovery of transiting extrasolar planets has enabled us to do a number of interesting studies. Transit photometry reveals the radius and the orbital inclination of transiting planets, which allows us to learn the true mass and density of the respective planets by the combined information from radial velocity (RV) measurements. In addition, follow-up observations of transiting planets, looking at such things as secondary eclipses, transit timing variations, transmission spectroscopy, and the Rossiter-McLaughlin effect, provide us information about their dayside temperatures, unseen bodies in systems, planetary atmospheres, and the obliquity of planetary orbits. Such observational information, which will provide us a greater understanding of extrasolar planets, is available only for transiting planets. Here, I briefly summarize what we can learn from transiting planets and introduce previous studies.

  11. Applying a reservoir functional-zone paradigm to littoral bluegills: differences in length and catch frequency?

    Directory of Open Access Journals (Sweden)

    Nathan Ruhl

    2014-08-01

    Full Text Available Reservoirs exhibit gradients in conditions and resources along the transition from lotic to lentic habitat that may be important to bluegill ecology. The lotic–lentic gradient can be partitioned into three functional zones: the riverine, transitional, and lacustrine zones. We measured catch frequency and length of bluegills (Lepomis macrochirus captured along the periphery of these areas (i.e., in the littoral zone of each functional zone for four small reservoirs in Southeastern Ohio during the summer months of three years. Catch frequency differed between zones for two reservoirs, but these differences were not observed in other years. There was no relationship between reservoir zone and either standard length or catch frequency when the data for all reservoirs were pooled, but we did observe a bimodal length distribution in all reservoirs. A combination of ecological factors including inter and intraspecific competition, predation intensity, management practices, limnology, and assemblage complexity may be mitigating bluegill distribution and abundance in reservoirs. Therefore, a functional zone (categorical approach to understanding bluegill ecology in reservoirs may not be appropriate.

  12. India's population in transition.

    Science.gov (United States)

    Visaria, L; Visaria, P

    1995-10-01

    This demographic profile of India addresses fertility, family planning, and economic issues. India is described as a country shifting from economic policies of self-reliance to active involvement in international trade. Wealth has increased, particularly at higher educational levels, yet 25% still live below the official poverty line and almost 66% of Indian women are illiterate. The government program in family planning, which was instituted during the early 1950s, did not change the rate of natural increase, which remained stable at 2.2% over the past 30 years. 1993 marked the first time the growth rate decline to under 2%. The growth rate in 1995 was 1.9%. The total population is expected double in 36 years. Only Nigeria, Pakistan, and Bangladesh had a higher growth rate and higher fertility in 1995. India is geographically diverse (with the northern Himalayan mountain zone, the central alluvial plains, the western desert region, and the southern peninsula with forest, mountains, and plains). There are regional differences in the fertility rates, which range from replacement level in Kerala and Goa to 5.5 children in Uttar Pradesh. Fertility is expected to decline throughout India due to the slower pace of childbearing among women over the age of 35 years, the increase in contraceptive use, and increases in marriage age. Increased educational levels in India and its state variations are related to lower fertility. Literacy campaigns are considered to be effective means of increasing the educational levels of women. Urbanization is not expected to markedly affect fertility levels. Urban population, which is concentrated in a few large cities, remains a small proportion of total population. Greater shifts are evident in the transition from agriculture to other wage labor. Fertility is expected to decline as women's share of labor force activity increases. The major determinant of fertility decline in India is use of family planning, which has improved in access

  13. SEMIAUTOMATIC DETECTION OF TUMORAL ZONE

    Directory of Open Access Journals (Sweden)

    Ezzeddine Zagrouba

    2011-05-01

    Full Text Available This paper describes a robust method based on the cooperation of fuzzy classification and regions segmentation algorithms, in order to detect the tumoral zone in the brain Magnetic Resonance Imaging (MRI. On one hand, the classification in fuzzy sets is done by the Fuzzy C-Means algorithm (FCM, where a study of its different parameters and its complexity has been previously realised, which led us to improve it. On the other hand, the segmentation in regions is obtained by an hierarchical method through adaptive thresholding. Then, an operator expert selects a germ in the tumoral zone, and the class containing the sick zone is localised in return for the FCM algorithm. Finally, the superposition of the two partitions of the image will determine the sick zone. The originality of our approach is the parallel exploitation of different types of information in the image by the cooperation of two complementary approaches. This allows us to carry out a pertinent approach for the detection of sick zone in MRI images.

  14. State Enterprise Zone Programs: Have They Worked?

    Science.gov (United States)

    Peters, Alan H.; Fisher, Peter S.

    The effectiveness of state enterprise zone programs was examined by using a hypothetical-firm model called the Tax and Incentives Model-Enterprise Zones (TAIM-ez) model to analyze the value of enterprise zone incentives to businesses across the United States and especially in the 13 states that had substantial enterprise zone programs by 1990. The…

  15. 33 CFR 165.20 - Safety zones.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety zones. 165.20 Section 165... WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS Safety Zones § 165.20 Safety zones. A Safety Zone is a water area, shore area, or water and shore area to which, for safety or environmental...

  16. 46 CFR 76.23-5 - Zoning.

    Science.gov (United States)

    2010-10-01

    ... deck, large common areas may be zoned in accordance with table 76.23-5(b). All such zones within one common area shall be of approximately the same size. Zones of this type shall overlap in such a manner that the end sprinkler heads of both adjoining zones will cover the identical area. Table 76.23-5(b...

  17. Zone distillation: a new purification method

    International Nuclear Information System (INIS)

    Kravchenko, A.I.

    2011-01-01

    The features of zone distillation (with zone melting of refined material and with pulling of condensate) as a new purification method are shown. The method is based on similarity of equations of distillation and crystallization refining. The analogy between some distillation and condensation methods (particularly between zone distillation and zone recrystallization) is should up

  18. A fingerprint of the epileptogenic zone in human epilepsies.

    Science.gov (United States)

    Grinenko, Olesya; Li, Jian; Mosher, John C; Wang, Irene Z; Bulacio, Juan C; Gonzalez-Martinez, Jorge; Nair, Dileep; Najm, Imad; Leahy, Richard M; Chauvel, Patrick

    2018-01-01

    Defining a bio-electrical marker for the brain area responsible for initiating a seizure remains an unsolved problem. Fast gamma activity has been identified as the most specific marker for seizure onset, but conflicting results have been reported. In this study, we describe an alternative marker, based on an objective description of interictal to ictal transition, with the aim of identifying a time-frequency pattern or 'fingerprint' that can differentiate the epileptogenic zone from areas of propagation. Seventeen patients who underwent stereoelectroencephalography were included in the study. Each had seizure onset characterized by sustained gamma activity and were seizure-free after tailored resection or laser ablation. We postulated that the epileptogenic zone was always located inside the resection region based on seizure freedom following surgery. To characterize the ictal frequency pattern, we applied the Morlet wavelet transform to data from each pair of adjacent intracerebral electrode contacts. Based on a visual assessment of the time-frequency plots, we hypothesized that a specific time-frequency pattern in the epileptogenic zone should include a combination of (i) sharp transients or spikes; preceding (ii) multiband fast activity concurrent; with (iii) suppression of lower frequencies. To test this hypothesis, we developed software that automatically extracted each of these features from the time-frequency data. We then used a support vector machine to classify each contact-pair as being within epileptogenic zone or not, based on these features. Our machine learning system identified this pattern in 15 of 17 patients. The total number of identified contacts across all patients was 64, with 58 localized inside the resected area. Subsequent quantitative analysis showed strong correlation between maximum frequency of fast activity and suppression inside the resection but not outside. We did not observe significant discrimination power using only the maximum

  19. Problems of Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    1996-01-01

    The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved. The collection comprises the information for scientists, experts, postgraduates and students in gaged in ecology, radioecology, nuclear engineering, radiology, radiochemistry and radiobiology

  20. Dual-zone boiling process

    International Nuclear Information System (INIS)

    Bennett, D.L.; Schwarz, A.; Thorogood, R.M.

    1987-01-01

    This patent describes a process for boiling flowing liquids in a heat exchanger wherein the flowing liquids is heated in a single heat exchanger to vaporize the liquid. The improvement described here comprises: (a) passing the boiling flowing liquid through a first heat transfer zone of the heat exchanger comprising a surface with a high-convective-heat-transfer characteristic and a higher pressure drop characteristic; and then (b) passing the boiling flowing liquid through a second heat transfer zone of the heat exchanger comprising an essentially open channel with only minor obstructions by secondary surfaces, with an enhanced nucleate boiling heat transfer surface and a lower pressure drop characteristic

  1. Methods for converting industrial zones

    Science.gov (United States)

    Talipova, L.; Kosyakov, E.; Polyakova, Irina

    2017-10-01

    In this article, industrial zones of Saint Petersburg and Hong Kong were considered. Competitive projects aimed at developing the grey belt of Saint Petersburg were considered. The methodology of the survey of reconstruction of the industrial zone of Hong Kong is also analyzed. The potential of the city’s grey belt lies in its location on the border of the city’s historical centre. Rational use of this potential will make it possible to achieve numerous objectives, including development of the city’s transport infrastructure, positioning of business functions, and organization of housing and the city’s system of green public spaces.

  2. [Cytostructure of the mantle zone in lymphatic tissue].

    Science.gov (United States)

    Bednár, B

    1993-04-01

    Four cellular layers of the follicular mantle zone in palatine tonsil lymphatic tissue were studied by electron microscopy after simultaneous immunophenotypical investigation. The first layer of the mantle zone consisting of small blastic cells was analogous to the small (centrocytoid) blastic layer of germinal centres. The second B monocytoid layer was lacking analogy in basic series of lymphocytes and seemed to be an independent morphological and probably functional unit. Plasmacytoid and clarocellular elements in outer layers of follicular mantle zone were in a way similar to T plasmacytoid and clarocellular components of Sézary syndrome infiltrates but considering transitional forms they had a local origin from incompletely transformed elements of B monocytoid layer. Inner follicular mantle zone was discussed as a source of incompletely transformed B lymphocytes for further mantle layers where their immunophenotypical modulation is taking place according to actual need. Outer mantle layers are aggressive against damaged epithelial and litoral structures and may be instrumental in a common reaction of B and T components.

  3. Workers in transition

    OpenAIRE

    Rutkowski, Michael

    1995-01-01

    After Central and Eastern European and Central Asian economies abandoned central planning, nearly 195 million workers had to adjust to new rules of work and life. Most transition economies have not yet fully committed themselves to the rules of the market place. A few that have are already enjoying growth in wages and employment; in other countries, labor income growth is still to come. Reform has not been so well accepted in countries that were forced to enter the transition. Transition brou...

  4. Transition and Social networks

    OpenAIRE

    Raghavan, Raghu; Pawson, N.

    2011-01-01

    School leavers with learning disabilities often face difficulties in making a smooth transition from school to college, employment or more broadly, to adult life. The transition phase is traumatic for the young person with learning disabilities and their families as it often results in the loss of friendships, relationships and social networks. The aim of this chapter is to explore the issues of transition from adolescence to adulthood for young people with learning disabilities and its effe...

  5. Seismotectonic zoning of Azerbaijan territory

    Science.gov (United States)

    Kangarli, Talat; Aliyev, Ali; Aliyev, Fuad; Rahimov, Fuad

    2017-04-01

    Studying of the space-time correlation and consequences effect between tectonic events and other geological processes that have created modern earth structure still remains as one of the most important problems in geology. This problem is especially important for the East Caucasus-South Caspian geodynamic zone. Being situated at the eastern part of the Caucasian strait, this zone refers to a center of Alpine-Himalayan active folded belt, and is known as a complex tectonic unit with jointing heterogeneous structural-substantial complexes arising from different branches of the belt (Doburja-Caucasus-Kopetdag from the north and Pyrenean-Alborz from the south with Kura and South Caspian zone). According to GPS and precise leveling data, activity of regional geodynamic processes shows intensive horizontal and vertical movements of the Earth's crust as conditioned by collision of the Arabian and Eurasian continental plates continuing since the end of Miocene. So far studies related to the regional of geology-geophysical data, periodically used for the geological and tectonic modeling of the environment mainly based on the fixing ideology. There still remains a number of uncertainties in solution of issues related to regional geology, tectonics and magmatism, structure and interrelation of different structural zones, space-time interrelations between onshore and offshore complexes, etc. At the same time large dataset produced by surface geological surveys, deep geological mapping of on- and offshore areas with the use of seismic and electrical reconnaissance and geophysical field zoning methods, deep well drilling and remote sensing activities. Conducted new studies produced results including differentiation of formerly unknown nappe complexes of the different ages and scales within the structure of mountain-fold zones, identification of new zones containing ophiolites in their section, outlining of currently active faulting areas, geophysical interpretation of the deep

  6. Geochemistry of subduction zone serpentinites: A review

    Science.gov (United States)

    Deschamps, Fabien; Godard, Marguerite; Guillot, Stéphane; Hattori, Kéiko

    2013-09-01

    Over the last decades, numerous studies have emphasized the role of serpentinites in the subduction zone geodynamics. Their presence and role in subduction environments are recognized through geophysical, geochemical and field observations of modern and ancient subduction zones and large amounts of geochemical database of serpentinites have been created. Here, we present a review of the geochemistry of serpentinites, based on the compilation of ~ 900 geochemical data of abyssal, mantle wedge and exhumed serpentinites after subduction. The aim was to better understand the geochemical evolution of these rocks during their subduction as well as their impact in the global geochemical cycle. When studying serpentinites, it is essential to determine their protoliths and their geological history before serpentinization. The geochemical data of serpentinites shows little mobility of compatible and rare earth elements (REE) at the scale of hand-specimen during their serpentinization. Thus, REE abundance can be used to identify the protolith for serpentinites, as well as magmatic processes such as melt/rock interactions before serpentinization. In the case of subducted serpentinites, the interpretation of trace element data is difficult due to the enrichments of light REE, independent of the nature of the protolith. We propose that enrichments are probably not related to serpentinization itself, but mostly due to (sedimentary-derived) fluid/rock interactions within the subduction channel after the serpentinization. It is also possible that the enrichment reflects the geochemical signature of the mantle protolith itself which could derive from the less refractory continental lithosphere exhumed at the ocean-continent transition. Additionally, during the last ten years, numerous analyses have been carried out, notably using in situ approaches, to better constrain the behavior of fluid-mobile elements (FME; e.g. B, Li, Cl, As, Sb, U, Th, Sr) incorporated in serpentine phases

  7. 77 FR 30245 - Safety Zones; Annual Fireworks Events in the Captain of the Port Detroit Zone

    Science.gov (United States)

    2012-05-22

    ...'' N, 082-51'-18.70'' W (NAD 83). This proposed zone would be enforced one evening during the last week...-AA00 Safety Zones; Annual Fireworks Events in the Captain of the Port Detroit Zone AGENCY: Coast Guard... by adding three permanent safety zones within the Captain of the Port Detroit Zone. This action is...

  8. Thermodynamics of phase transitions

    International Nuclear Information System (INIS)

    Cofta, H.

    1972-01-01

    The phenomenology of the phase transitions has been considered. The definitions of thermodynamic functions and parameters, as well as those of the phase transitions, are given and some of the relations between those quantities are discussed. The phase transitions classification proposed by Ehrenfest has been described. The most important features of phase transitions are discussed using the selected physical examples including the critical behaviour of ferromagnetic materials at the Curie temperature and antiferromagnetic materials at the Neel temperature. Some aspects of the Ehrenfest's equations, that have been derived, for the interfacial lines and surfaces are considered as well as the role the notion of interfaces. (S.B.)

  9. The Energy Transition Chronicles

    International Nuclear Information System (INIS)

    Cappelletti, Floriane; Vallar, Jean-Pierre; Wyssling, Julia

    2015-01-01

    Energy Cities provides local authorities with support for implementing their own energy transition process. The Proposals for the energy transition of cities and towns (www.energy-cities.eu/30proposals) are illustrated with around a hundred of inspirational examples from all over Europe. In this document composed of five case reports, Energy Cities goes further and tells the tale of energy transition success stories. Because it is important to show that energy transition is 'possible'. Why, how, with whom, for what results? We interviewed local players and decision-makers to find out more. Here are their stories

  10. Transit Benefit Program Data -

    Data.gov (United States)

    Department of Transportation — This data set contains information about any US government agency participating in the transit benefits program, funding agreements, individual participating Federal...

  11. ShoreZone Mapped Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is a polyline file of mapped ShoreZone units which correspond with data records found in the Unit, Xshr, BioUnit, and BioBand tables of this...

  12. Issues in Coastal Zone Management.

    Science.gov (United States)

    Davis, Derrin

    1992-01-01

    Addresses the following issues relevant to coastal zone management: overcrowding, resource exploitation, pollution, agriculture, fisheries, industrial, and other uses. Describes conflicts and trade-offs in management typified by fragmented agency decision making. Discusses implications of the greenhouse effect, sustainable development, and the…

  13. Street prostitution zones and crime

    NARCIS (Netherlands)

    Bisschop, P.; Kastoryano, S.; van der Klaauw, B.

    2017-01-01

    This paper studies the effects of legal street prostitution zones on registered and perceived crime. We exploit a unique setting in the Netherlands where these tippelzones were opened in nine cities under different regulation systems. Our difference-in-difference analysis of 25 Dutch cities between

  14. Land governance as grey zone

    DEFF Research Database (Denmark)

    Kjær, Anne Mette

    2017-01-01

    demonstrates that in Uganda, the need to maintain the ruling coalition in a clientelist political settlement to build electoral support, and the desire to attract economic investors, constitute political incentives to maintain land governance as a grey zone, even if there is apparent political...

  15. Lithium inputs to subduction zones

    NARCIS (Netherlands)

    Bouman, C.; Elliott, T.R.; Vroon, P.Z.

    2004-01-01

    We have studied the sedimentary and basaltic inputs of lithium to subduction zones. Various sediments from DSDP and ODP drill cores in front of the Mariana, South Sandwich, Banda, East Sunda and Lesser Antilles island arcs have been analysed and show highly variable Li contents and δ

  16. 77 FR 25080 - Safety Zones; TriMet Bridge Project, Willamette River, Portland, OR

    Science.gov (United States)

    2012-04-27

    .... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing safety zones encompassing the work... Guard. Collection of Information This rule calls for no new collection of information under the... vessels transiting in close proximity to cranes and overhead work associated with this construction...

  17. 33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

    Science.gov (United States)

    2010-07-01

    ... Petroleum Gas, the waters within a 500 yard radius of the LPG carrier while the vessel transits the Corpus Christi Ship Channel to the LPG receiving facility. The safety zone remains in effect until the LPG vessel is moored at the LPG receiving facility. (2) For outgoing tank vessels loaded with LPG, the waters...

  18. 75 FR 18056 - Safety Zone; Fireworks Display, Patuxent River, Solomons Island Harbor, MD

    Science.gov (United States)

    2010-04-09

    ... the event, and enhancing public and maritime safety. Basis and Purpose Fireworks displays are... promote public and maritime safety during a fireworks display, and to protect mariners transiting the area...-AA00 Safety Zone; Fireworks Display, Patuxent River, Solomons Island Harbor, MD AGENCY: Coast Guard...

  19. Lower and Upper Bounds in Zone-Based Abstractions of Timed Automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Bouyer, Patricia; Larsen, Kim Guldstrand

    2005-01-01

    The semantics of timed automata is defined using an infinite-state transition system. For verification purposes, one usually uses zone based abstractions w.r.t. the maximal constants to which clocks of the timed automaton are compared. We show that by distinguishing maximal lower and upper bounds...

  20. Environmental evolution and builders of small hills - India Muerta zone. A restatement

    International Nuclear Information System (INIS)

    Bracco, R.; Del Puerto, L.; Inda, H.; Capdepont, I.; Panario, D.; Garcia Rodriguez, F.

    2012-01-01

    This work is about the study carried out in India Muerta zone - Rocha town. The Paleoclimatology, the Geoarchaeology and Carbon14 dating information enable to conclude that the first inhabitants of the region has constructed the small hills for a transitional climatic period. This period belongs to the Holocene and is characterized by a humidity contraction process

  1. 75 FR 63086 - Great Mississippi Balloon Race and Fireworks Safety Zone; Lower Mississippi River, Mile Marker...

    Science.gov (United States)

    2010-10-14

    ... flying hot air balloons transiting across the Lower Mississippi River. Entry into this zone is prohibited... mariners from the safety hazards associated with a fireworks display and low flying hot air balloons... mariners from the safety hazards associated with a fireworks display and low flying hot air balloons...

  2. 77 FR 14970 - Safety Zones; Sellwood Bridge Project, Willamette River; Portland, OR

    Science.gov (United States)

    2012-03-14

    ... upriver and downriver of the existing Sellwood Bridge, inward 375 feet from the Western side shoreline... times. These safety zones will ensure the safety of all vessels and crew that are working and transiting... against small entities that question or complain about this rule or any policy or action of the Coast...

  3. Fifty years of shear zones

    Science.gov (United States)

    Graham, Rodney

    2017-04-01

    We are here, of course, because 1967 saw the publication of John Ramsay's famous book. Two years later a memorable field trip from Imperial College to the Outer Hebrides saw John on a bleak headland on the coast of North Uist where a relatively undeformed metadolerite within Lewisian (Precambrian) gneisses contained ductile shear zones with metamorphic fabrics in amphibolite facies. One particular outcrop was very special - a shear zone cutting otherwise completely isotropic, undeformed metadolerite, with an incremental foliation starting to develop at 45° to the deformation zone, and increasing in intensity as it approached the shear direction. Here was proof of the process of simple shear under ductile metamorphic conditions - the principles of simple shear outlined in John Ramsay's 1967 book clearly visible in nature, and verified by Ramsay's mathematical proofs in the eventual paper (Ramsay and Graham, 1970). Later work on the Lewisian on the mainland of Scotland, in South Harris, in Africa, and elsewhere applied Ramsay's simple shear principles more liberally, more imprecisely and on larger scale than at Caisteal Odair, but in retrospect it documented what seems now to be the generality of mid and lower crustal deformation. Deep seismic reflection data show us that on passive margins hyper-stretched continental crust (whether or not cloaked by Seaward Dipping Reflectors) seems to have collapsed onto the mantle. Crustal faults mostly sole out at or above the mantle - so the Moho is a detachment- an 'outer marginal detachment', if you like, and, of course, it must be a ductile shear. On non-volcanic margins this shear zone forms the first formed ocean floor before true sea floor spreading gets going to create real oceanic crust. Gianreto Manatschal, Marcel Lemoine and others realised that the serpentinites described in parts of the Alps are exposed remnants of this ductile shear zone. Associated ophicalcite breccias tell of sea floor exposure, while high

  4. Eigenstate Phase Transitions

    Science.gov (United States)

    Zhao, Bo

    Phase transitions are one of the most exciting physical phenomena ever discovered. The understanding of phase transitions has long been of interest. Recently eigenstate phase transitions have been discovered and studied; they are drastically different from traditional thermal phase transitions. In eigenstate phase transitions, a sharp change is exhibited in properties of the many-body eigenstates of the Hamiltonian of a quantum system, but not the thermal equilibrium properties of the same system. In this thesis, we study two different types of eigenstate phase transitions. The first is the eigenstate phase transition within the ferromagnetic phase of an infinite-range spin model. By studying the interplay of the eigenstate thermalization hypothesis and Ising symmetry breaking, we find two eigenstate phase transitions within the ferromagnetic phase: In the lowest-temperature phase the magnetization can macroscopically oscillate by quantum tunneling between up and down. The relaxation of the magnetization is always overdamped in the remainder of the ferromagnetic phase, which is further divided into phases where the system thermally activates itself over the barrier between the up and down states, and where it quantum tunnels. The second is the many-body localization phase transition. The eigenstates on one side of the transition obey the eigenstate thermalization hypothesis; the eigenstates on the other side are many-body localized, and thus thermal equilibrium need not be achieved for an initial state even after evolving for an arbitrary long time. We study this many-body localization phase transition in the strong disorder renormalization group framework. After setting up a set of coarse-graining rules for a general one dimensional chain, we get a simple "toy model'' and obtain an almost purely analytical solution to the infinite-randomness critical fixed point renormalization group equation. We also get an estimate of the correlation length critical exponent nu

  5. Irradiation damage 'displacement zone'; Dommages sous irradiation zone de deplacements

    Energy Technology Data Exchange (ETDEWEB)

    Genthon, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    It is well known that a charged particle (ion, primary atom, etc...) moving in a solid slows down and can cause a cascade of displacements of the atoms in the solid. A study is made here of the extent to which the cascade is made up, or not, of independent collisions, as a function of the energy of the initial charged particle. When the distance between the collisions is small, these latter are no longer independent; the cascade, which then has to be considered as a whole, perturbs and locates, in the irradiated solid , a zone which has been named a 'displacement zone'. It is shown that the proportion of displacement zones increases with increasing atom size (high atomic number Z), with decreasing atomic distance D in the substance considered and with decreasing energy of the ion undergoing the slowing down process (although always remaining above a few hundred eV). The proportions obtained are higher than those corresponding to the calculations of J. A. Brinkman [3]. An interatomic potential required for this work has also been determined. (author) [French] On sait qu'une particule chargee (ions, atomes primaires, etc...) en mouvement dans un solide se ralentit, avec eventuellement deplacement en cascade d'atomes du solide. On etudie ici dans quelle proportion, en fonction de l'energie de la particule chargee initiale, la cascade est constituee, ou non, de 'chocs independants'. Lorsque la distance entre chocs est petite, ceux-ci ne sont plus independants; la cascade, qui doit alors etre consideree dans son ensemble, perturbe et definit dans le solide irradie, une zone qu'on a appele zone de deplacements. On montre que la proportion de zones de deplacements est d'autant plus grande que les atomes sont gros (nombre atomique Z grand), que la distance interatomique D est petite dans le corps considere, et que l'energie de l'ion en ralentissement est petite (tout en restant superieure a quelques centaines d'eV). Les proportions obtenues sont superieures a celles qui

  6. High resolution, topobathymetric LiDAR coastal zone characterization in Denmark

    DEFF Research Database (Denmark)

    Steinbacher, Frank; Baran, Ramona; Andersen, Mikkel S.

    2016-01-01

    Coastal and tidal environments are valuable ecosystems, which, however, are under pressure in many areas around the world due to globalization and/or climate change. Detailed mapping of these environments is required in order to manage the coastal zone in a sustainable way. However, historically...... locations with different environmental settings. We demonstrate the potential of using airborne topobathymetric LiDAR for seamless mapping of land-water transition zones in challenging coastal environments, e.g. in an environment with high water column turbidity and continuously varying water levels due...... these transition zones between land and water are difficult or even impossible to map and investigate in high spatial resolution due to the challenging environmental conditions. The new generation of airborne topobathymetric light detection and ranging (LiDAR) potentially enables full-coverage and high...

  7. The gravel sand transition in a disturbed catchment

    Science.gov (United States)

    Knighton, A. David

    1999-03-01

    More than 40 million cubic metres of mining waste were supplied to the Ringarooma River between 1875 and 1984, leading to successive phases of aggradation and degradation. The natural bed material is gravel but, given the volume of introduced load and the fact that much of the input was less than 5 mm in diameter, the size composition of the bed changed from gravel to sand during the phase of downstream progressive aggradation. A very sharp gravel-sand transition developed in which median grain size decreased from over 30 mm to under 3 mm in less than 500 m. With upstream supplies of mining debris becoming depleted first, degradation followed the same downstream progressive pattern as aggradation, causing the transition to migrate downstream. By 1984, the river could be regarded as a series of zones, each characterized by a particular bed condition: a natural cobble-gravel bed, unaffected by mining inputs (0-32 km); pre-disturbance bed re-exposed by degradation over 35-40 years (32-53 km); sandy substrate with a gravel armour produced by differential transport during degradation (53-65 km); sand dominated but with developing surface patches of coarser material (65-75 km); sandy bed reflecting the size composition of the original mining input (75-118 km). Although the gravel-sand transition itself is sharp, the transitional zone is lengthy (53-75 km). As degradation continues, the gravel-sand transition is expected to progress downstream but it has remained in a stable position for 12 years. Indeed, two major floods during the period released large quantities of sand from the sub-armour layer and newly-formed banks of mine tailings, causing fining both above and below the transition. Surface grain size is an adjustable component in the transitional zone as the river strives to recover from a major anthropogenic disturbance.

  8. 77 FR 6007 - Quarterly Listings; Safety Zones, Security Zones, Special Local Regulations, Drawbridge Operation...

    Science.gov (United States)

    2012-02-07

    ...] Quarterly Listings; Safety Zones, Security Zones, Special Local Regulations, Drawbridge Operation... they could be published in the Federal Register. This notice lists temporary safety zones, security... the safety and security needs within their jurisdiction; therefore, District Commanders and COTPs have...

  9. Transitivity of Preferences

    Science.gov (United States)

    Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

    2011-01-01

    Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to…

  10. Alaska Community Transit

    Science.gov (United States)

    Grant Information Human Services Funding 5310 5316 (Repealed) 5317 (Repealed) Alaska Mental Health Trust Department of Transportation & Public Facilities/ Alaska Community Transit Search DOT&PF State of Alaska Photo banner DOT&PF> Program Development > Alaska Community Transit Home About Us

  11. Distance-transitive graphs

    NARCIS (Netherlands)

    Cohen, A.M.; Beineke, L.W.; Wilson, R.J.; Cameron, P.J.

    2004-01-01

    In this chapter we investigate the classification of distance-transitive graphs: these are graphs whose automorphism groups are transitive on each of the sets of pairs of vertices at distance i, for i = 0, 1,.... We provide an introduction into the field. By use of the classification of finite

  12. Towards Transition Theory

    NARCIS (Netherlands)

    J. de Haan (Hans)

    2010-01-01

    textabstractThis thesis is a treatise on a theory for societal transitions: pillar theory. Societal transitions are complex processes taking place in complex systems, large-scale, long-term processes in which societal systems radically change the way they are composed and function. Since we all are

  13. Matter in transition

    International Nuclear Information System (INIS)

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-01-01

    We explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, where a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.

  14. Transitional Employment Programs.

    Science.gov (United States)

    Dulle, Paul J.; And Others

    The paper examines the need and implementation of transitional employment programs for handicapped youth. Effects on the handicapped of future automation are considered along with the need for school-business cooperation to prepare for the future. The importance of initial success in any innovation is noted. A Chicago transitional employment…

  15. Transitive probabilistic CLIR models.

    NARCIS (Netherlands)

    Kraaij, W.; de Jong, Franciska M.G.

    2004-01-01

    Transitive translation could be a useful technique to enlarge the number of supported language pairs for a cross-language information retrieval (CLIR) system in a cost-effective manner. The paper describes several setups for transitive translation based on probabilistic translation models. The

  16. Bridging the Transition Gap

    Science.gov (United States)

    2013-05-23

    period and provide recommendations to guide future research and policy development. 4 DEFINING THE TRANSITIONAL SECURITY GAP There have been...BRIDGING THE TRANSITION GAP A Monograph by MAJ J.D. Hansen United States Army School of Advanced Military Studies United States Army...suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704

  17. Transition probabilities for atoms

    International Nuclear Information System (INIS)

    Kim, Y.K.

    1980-01-01

    Current status of advanced theoretical methods for transition probabilities for atoms and ions is discussed. An experiment on the f values of the resonance transitions of the Kr and Xe isoelectronic sequences is suggested as a test for the theoretical methods

  18. The hydraulic properties of fracture zones and tracer tests with non-reactive elements in Studsvik

    International Nuclear Information System (INIS)

    Klockars, C.-E.; Persson, O.; Landstroem, O.

    1982-04-01

    Tracer technique was applied in a rock formation within the Studsvik Energiteknik area in order to study hydrodynamic properties of discrete fracture zones between boreholes. The two hole method was applied in these studies; a nonreactive tracer is injected in one hole into a fracture zone which is in hydraulic contact with a central pump hole (observation hole). Hydraulic tests and TV inspection were carried out in the fracture zones. Chemical composition of the groundwater was determined. In summary, the following hydraulic properties were found for the fracture zones between the boreholes B1N-B6N and B5N-B6N respectively, under the prevailing conditions: 1) The fracture zones studied consists of a number of transport pathways with different mean transit times, varying from 100 to 1200 hours. 2) The fracture zone between boreholes B1N and B6N has a mean hydraulic conductivity of 6-7 x 10 -5 m/s and the fracture zone between boreholes B5N and B6N, 2 x 10 -4 m/s. 3) The kinematic porosity of the fracture zones studied, calculated as the ratio between the hydraulic conductivity of the rock mass and that of the fracture zone, is 2 x 10 -3 and 5 x 10 -3 , respectively. 4) The roughness factor β, which expresses the ratio between measured and theoretically calculated (plane-parallel) fracture conductivity for the fracture zones studied, is approximately 0.04 and 0.06, respectively. 5) Dispersivity for the flow channels within the fracture zones is of the order of 0.3-0.8 m. 6) The groundwater encountered is a nearly neutral, probably reducing, Na-Ca-HCO 3 water. The results of the tracer tests reveal the following: I-131 is a suitable nonreactive tracer for the test area. A test with simultaneous injection of I-131 and T (tritium) gave comparable breakthrough curves. (Author)

  19. Contemporary Transitional Justice

    DEFF Research Database (Denmark)

    Gissel, Line Engbo

    2017-01-01

    This article studies the contemporary expression of transitional justice, a field of practice through which global governance is exercised. It argues that transitional justice is being normalised, given the normative and empirical de-legitimisation of its premise of exceptionalism. The article...... theorises exceptionalism and normalcy in transitional justice and identifies three macro-level causes of normalisation: the legalisation, internationalisation, and professionalization of the field. This argument is illustrated by a study of Uganda’s trajectory of transitional justice since 1986. Across five...... phases of transitional justice, processes of legalisation, internationalisation, and professionalization have contributed to the gradual dismantling of the country’s exceptional justice. The case demonstrates, further, that normalization is a contested and incomplete process....

  20. Unsaturated Zone and Saturated Zone Transport Properties (U0100)

    Energy Technology Data Exchange (ETDEWEB)

    J. Conca

    2000-12-20

    This Analysis/Model Report (AMR) summarizes transport properties for the lower unsaturated zone hydrogeologic units and the saturated zone at Yucca Mountain and provides a summary of data from the Busted Butte Unsaturated Zone Transport Test (UZTT). The purpose of this report is to summarize the sorption and transport knowledge relevant to flow and transport in the units below Yucca Mountain and to provide backup documentation for the sorption parameters decided upon for each rock type. Because of the complexity of processes such as sorption, and because of the lack of direct data for many conditions that may be relevant for Yucca Mountain, data from systems outside of Yucca Mountain are also included. The data reported in this AMR will be used in Total System Performance Assessment (TSPA) calculations and as general scientific support for various Process Model Reports (PMRs) requiring knowledge of the transport properties of different materials. This report provides, but is not limited to, sorption coefficients and other relevant thermodynamic and transport properties for the radioisotopes of concern, especially neptunium (Np), plutonium (Pu), Uranium (U), technetium (Tc), iodine (I), and selenium (Se). The unsaturated-zone (UZ) transport properties in the vitric Calico Hills (CHv) are discussed, as are colloidal transport data based on the Busted Butte UZTT, the saturated tuff, and alluvium. These values were determined through expert elicitation, direct measurements, and data analysis. The transport parameters include information on interactions of the fractures and matrix. In addition, core matrix permeability data from the Busted Butte UZTT are summarized by both percent alteration and dispersion.

  1. Unsaturated Zone and Saturated Zone Transport Properties (U0100)

    International Nuclear Information System (INIS)

    Conca, J.

    2000-01-01

    This Analysis/Model Report (AMR) summarizes transport properties for the lower unsaturated zone hydrogeologic units and the saturated zone at Yucca Mountain and provides a summary of data from the Busted Butte Unsaturated Zone Transport Test (UZTT). The purpose of this report is to summarize the sorption and transport knowledge relevant to flow and transport in the units below Yucca Mountain and to provide backup documentation for the sorption parameters decided upon for each rock type. Because of the complexity of processes such as sorption, and because of the lack of direct data for many conditions that may be relevant for Yucca Mountain, data from systems outside of Yucca Mountain are also included. The data reported in this AMR will be used in Total System Performance Assessment (TSPA) calculations and as general scientific support for various Process Model Reports (PMRs) requiring knowledge of the transport properties of different materials. This report provides, but is not limited to, sorption coefficients and other relevant thermodynamic and transport properties for the radioisotopes of concern, especially neptunium (Np), plutonium (Pu), Uranium (U), technetium (Tc), iodine (I), and selenium (Se). The unsaturated-zone (UZ) transport properties in the vitric Calico Hills (CHv) are discussed, as are colloidal transport data based on the Busted Butte UZTT, the saturated tuff, and alluvium. These values were determined through expert elicitation, direct measurements, and data analysis. The transport parameters include information on interactions of the fractures and matrix. In addition, core matrix permeability data from the Busted Butte UZTT are summarized by both percent alteration and dispersion

  2. 78 FR 19103 - Safety Zone; Spanish Navy School Ship San Sebastian El Cano Escort; Bahia de San Juan; San Juan, PR

    Science.gov (United States)

    2013-03-29

    ...-AA00 Safety Zone; Spanish Navy School Ship San Sebastian El Cano Escort; Bahia de San Juan; San Juan... temporary moving safety zone on the waters of Bahia de San Juan during the transit of the Spanish Navy... Channel entrance, and to protect the high ranking officials on board the Spanish Navy School Ship San...

  3. Potential field signatures along the Zagros collision zone in Iran

    Science.gov (United States)

    Abedi, Maysam; Fournier, Dominique; Devriese, Sarah G. R.; Oldenburg, Douglas W.

    2018-01-01

    The Zagros orogenic belt, known as an active fold-thrust belt, was formed in southwestern Iran due to the convergence of the Arabian and Eurasian plates. In this study, potential field data are inverted in 3D to image the variations of magnetic susceptibility and density contrast along the collision zone, resulting in better tectonic understanding of the studied region. Geophysical data measured by airborne magnetic and ground-based gravity systems are used to construct an integrated model that facilitates the interpretations of various tectonic zones across a 450-km line. This line intersects the main structural units from the SW portion of the Zagros belt. The constructed model reveals a contrast that indicates the transition between the two continental plates coinciding with the western boundaries of the Sanandaj-Sirjan Zone (SSZ) at the Main Zagros Thrust (MZT) fault. The subduction of the Arabian continental crust below the Iranian one is evident because of its lower susceptibility property and alternating sequence of high and low density regions. Higher susceptibility, magnetic remanence and density are the mainstays of the Urumieh-Dokhtar Magmatic Assemblage (UDMA) zone at the NE of the studied route, whereas lower values of these properties correspond to (1) the thin massive Tertiary-Neogene and Quaternary sediments of the central domain (CD) zone, and (2) the thick sedimentary and salt intrusion cover over the Zagros Fold-and-Thrust belt (ZFTB). Higher density of regions in the Arabian crust below the ZFTB implies that fault activities have caused significant vertical displacement of the basement. Finally, a simplified geological model is presented based upon the inversions of the geophysical data, in which the main geological units are divided along the studied route.

  4. 33 CFR 165.169 - Safety and Security Zones: New York Marine Inspection Zone and Captain of the Port Zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones: New... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY... Areas First Coast Guard District § 165.169 Safety and Security Zones: New York Marine Inspection Zone...

  5. Coordination of IVI and transit signal priority on transit evacuations.

    Science.gov (United States)

    2011-02-01

    During an emergency evacuation, execution time is always critical to the evacuees who are : transit dependent. Transit Signal Priority (TSP) can speed up the transit services by prioritizing : the approaching bus at a signalized intersection. With th...

  6. Demarcation of secondary hyperalgesia zones

    DEFF Research Database (Denmark)

    Ringsted, Thomas K; Enghuus, Casper; Petersen, Morten A

    2015-01-01

    of analgesic drug effects in humans. However, since the methods applied in demarcating the secondary hyperalgesia zone seem inconsistent across studies, we examined the effect of a standardized approach upon the measurement of SHA following a first degree burn injury (BI). NEW METHOD: The study was a two.......0001). No day-to-day or observer-to-observer differences in SHAs were observed. Intraclass correlation coefficients, in the range of 0.51 to 0.84, indicated a moderate to almost perfect reliability between observers. COMPARISON WITH EXISTING METHODS: No standardized approach in SHA-assessment has hitherto been...... presented. CONCLUSIONS: This is the first study to demonstrate that demarcation of secondary hyperalgesia zones depends on the developed pressure of the punctate stimulator used....

  7. Control of penetration zone GMAW

    Directory of Open Access Journals (Sweden)

    Віталій Петрович Iванов

    2016-11-01

    Full Text Available Thermal properties of the base metal, shielding medium and the nature of the electrode metal transfer to a great extent determine the penetration area formation in gas-arc welding. It is not always possible to take into account the influence of these factors on penetration front forming within the existing models. The aim of the work was to research the penetration area forming in gas-arc welding. The research of the penetration area forming in gas-arc welding of CrNi austenitic steels was made. The parameters of the regime as well as the kind of the gaseous medium influence on the formation of the penetration zone were studied. The article shows a linear proportional relationship between the electrode feed rate and the size of the base metal plate. The penetration area formation mode for welding in argon and carbon dioxide have been worked out. Diameter, feed rate and the speed of the electrode movement have been chosen as the main input parameters. Multiple regression analysis method was used to make up the modes. The relations of the third order that make it possible to take into account the electrode metal transfer and thermal properties change of the materials to be welded were used. These relationships show quite good agreement with the experimental measurements in the calculation of the fusion zone shape with consumable electrode in argon and carbon dioxide. It was determined that the shape of the melting front curve can be shown as a generalized function in which the front motion parameters depend on feed rate and the diameter of the electrode. Penetration zone growth time is determined by the welding speed and is calculated as a discrete function of the distance from the electrode with the spacing along the movement coordinate. The influence of the mode parameters on the formation of the fusion zone has been investigated and the ways to manage and stabilize the weld pool formation have been identified. The modes can be used to develop

  8. Cosmological phase transitions

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1987-01-01

    If the universe stated from conditions of high temperature and density, there should have been a series of phase transitions associated with spontaneous symmetry breaking. The cosmological phase transitions could have observable consequences in the present Universe. Some of the consequences including the formation of topological defects and cosmological inflation are reviewed here. One of the most important tools in building particle physics models is the use of spontaneous symmetry breaking (SSB). The proposal that there are underlying symmetries of nature that are not manifest in the vacuum is a crucial link in the unification of forces. Of particular interest for cosmology is the expectation that are the high temperatures of the big bang symmetries broken today will be restored, and that there are phase transitions to the broken state. The possibility that topological defects will be produced in the transition is the subject of this section. The possibility that the Universe will undergo inflation in a phase transition will be the subject of the next section. Before discussing the creation of topological defects in the phase transition, some general aspects of high-temperature restoration of symmetry and the development of the phase transition will be reviewed. 29 references, 1 figure, 1 table

  9. Vadose Zone Journal: The first ten years

    NARCIS (Netherlands)

    Vrugt, J.A.; Or, D.; Young, M.H.

    2013-01-01

    Celebrating ten years of publication, the authors introduce a special section commemorating the anniversary of Vadose Zone Journal and reviewing the journal’s role in an evolving understanding of vadose zone science.

  10. Zoning, 2004, East Baton Rouge Parish, Louisiana

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a graphical polygon dataset depicting the zoning boundaries of the East Baton Rouge Parish of the State of Louisiana. Zoning can be defined as the range of...

  11. United States Stateplane Zones - NAD27

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — U.S. State Plane Zones (NAD 1927) represents the State Plane Coordinate System (SPCS) Zones for the 1927 North American Datum within United States.

  12. United States Stateplane Zones - NAD83

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — U.S. State Plane Zones (NAD 1983) represents the State Plane Coordinate System (SPCS) Zones for the 1983 North American Datum within United States.

  13. PLANT INVASIONS IN RHODE ISLAND RIPARIAN ZONES

    Science.gov (United States)

    The vegetation in riparian zones provides valuable wildlife habitat while enhancing instream habitat and water quality. Forest fragmentation, sunlit edges, and nutrient additions from adjacent development may be sources of stress on riparian zones. Landscape plants may include no...

  14. Buffer Zone Requirements for Soil Fumigant Applications

    Science.gov (United States)

    Updated pesticide product labels require fumigant users to establish a buffer zone around treated fields to reduce risks to bystanders. Useful information includes tarp testing guidance and a buffer zone calculator.

  15. Effectiveness of work zone intelligent transportation systems.

    Science.gov (United States)

    2013-12-01

    In the last decade, Intelligent Transportation Systems (ITS) have increasingly been deployed in work zones by state departments of transportation. Also known as smart work zone systems they improve traffic operations and safety by providing real-time...

  16. Zone Denmark - gasell Taanist / Reet Krause

    Index Scriptorium Estoniae

    Krause, Reet, 1967-

    2006-01-01

    Taanis Viborgis asuva firma Zone Company Denmark, kaubamärgi Zone Denmark ja firma disainerite tutvustus. Ettevõte valmistab disainitooteid roostevabast terasest, klaasist, puidust, kummist jm. Disainer Naja Utzon Popov endast, oma loomingust

  17. Milestoning with transition memory

    Science.gov (United States)

    Hawk, Alexander T.; Makarov, Dmitrii E.

    2011-12-01

    Milestoning is a method used to calculate the kinetics and thermodynamics of molecular processes occurring on time scales that are not accessible to brute force molecular dynamics (MD). In milestoning, the conformation space of the system is sectioned by hypersurfaces (milestones), an ensemble of trajectories is initialized on each milestone, and MD simulations are performed to calculate transitions between milestones. The transition probabilities and transition time distributions are then used to model the dynamics of the system with a Markov renewal process, wherein a long trajectory of the system is approximated as a succession of independent transitions between milestones. This approximation is justified if the transition probabilities and transition times are statistically independent. In practice, this amounts to a requirement that milestones are spaced such that trajectories lose position and velocity memory between subsequent transitions. Unfortunately, limiting the number of milestones limits both the resolution at which a system's properties can be analyzed, and the computational speedup achieved by the method. We propose a generalized milestoning procedure, milestoning with transition memory (MTM), which accounts for memory of previous transitions made by the system. When a reaction coordinate is used to define the milestones, the MTM procedure can be carried out at no significant additional expense as compared to conventional milestoning. To test MTM, we have applied its version that allows for the memory of the previous step to the toy model of a polymer chain undergoing Langevin dynamics in solution. We have computed the mean first passage time for the chain to attain a cyclic conformation and found that the number of milestones that can be used, without incurring significant errors in the first passage time is at least 8 times that permitted by conventional milestoning. We further demonstrate that, unlike conventional milestoning, MTM permits

  18. Martensitic phase transitions

    International Nuclear Information System (INIS)

    Petry, W.; Neuhaus, J.

    1996-01-01

    Many elements transform from a high temperature bcc phase to a more dense packed temperature phase. The great majority of these transitions are of 1st order, displacive and reconstructive. The lattice potentials which govern these martensitic transitions can be probed by inelastic neutron scattering, thereby answering fundamental questions like : Will the transition be announced by dynamical or static fluctuations? What are the trajectories for the displacements needed for the transformation? Does the vibrational entropy stabilize the high temperature phase? Are the unusual transport properties in these materials related to their ability to transform? (author) 17 figs., 1 tab., 46 refs

  19. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  20. Martensitic phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Petry, W; Neuhaus, J [Techn. Universitaet Muenchen, Physik Department E13, Munich (Germany)

    1996-11-01

    Many elements transform from a high temperature bcc phase to a more dense packed temperature phase. The great majority of these transitions are of 1st order, displacive and reconstructive. The lattice potentials which govern these martensitic transitions can be probed by inelastic neutron scattering, thereby answering fundamental questions like : Will the transition be announced by dynamical or static fluctuations? What are the trajectories for the displacements needed for the transformation? Does the vibrational entropy stabilize the high temperature phase? Are the unusual transport properties in these materials related to their ability to transform? (author) 17 figs., 1 tab., 46 refs.