Food flows in the United Kingdom: The potential of surplus food redistribution to reduce waste.

PubMed

Facchini, Elisa; Iacovidou, Eleni; Gronow, Jan; Voulvoulis, Nikolaos

2017-12-07

The increasing amount of food waste generated as a direct consequence of its excessive production, mismanagement, and wasteful behaviors represents a real challenge in promoting resource efficiency. In the United Kingdom (UK), the lack of robust mass flow data hinders the ability both to understand and address food waste challenges and to devise long-term sustainable prevention strategies. In recognition of these challenges, this paper seeks to (i) provide insights into the UK's annual estimates of food mass flows, including imports, exports, distribution, consumption, surplus food production, and final disposal; and (ii) scrutinize the uptake and redistribution of surplus food as a potential food waste prevention strategy. Evidence collected from several enterprises and community-led initiatives in the UK, and London specifically, supports that there is an increasing potential of making a shift towards food redistribution and reuse. Further analysis has shown that the outreach of food redistribution initiatives in the UK is currently limited, possibly because redistribution efforts remain largely fragmented and independent from each other. It is concluded that a national commitment could be instrumental in encouraging the roll-out of this practice, and governmental support through fiscal incentives could lead to the development of a larger and coherent surplus food redistribution system, ultimately enabling food waste prevention and recovery of food's multidimensional value. This paper deals with the topical issue of the increasing amount of food waste generated as a direct consequence of excessive production, mismanagement, and wasteful behavior, representing a real challenge in achieving sustainability and resource efficiency. Currently, only a small fraction of food is redistributed back into the system. Yet, a considerable fraction of food waste generated is edible; thus, better planning, storage, and coordination amongst the different stakeholders in the food supply chain is required in order to prevent its wastage and promote its reuse in accordance with the waste hierarchy.

Emerging investigator series: As( v ) in magnetite: incorporation and redistribution

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

Huhmann, Brittany L.; Neumann, Anke; Boyanov, Maxim I.

2017-01-01

As coprecipitated with magnetite remained incorporated over time whereas sorbed As was redistributed and became increasingly incorporated into magnetite, both the absence and presence of aqueous Fe(ii).

Aspects of hysteresis in unsaturated porous media flow

NASA Astrophysics Data System (ADS)

van Duijn, Hans

2016-04-01

About 20 years ago, Peter Raats and I wrote a technical note related to the horizontal redistribution in unsaturated porous media with hysteresis in the capillary pressure (P.A.C. Raats & C.J. van Duijn, A note on horizontal redistribution with capillary hysteresis, WWR 31, p. 231-232, 1995). In the first part of my presentation, I will revisit the results of that paper. In particular the cases of unconventional flow, where the water flows from the dry region to the wet region. A comparison will be made with results obtained with the current interface area models as introduced by Gray & Hassanizadeh. I will explain and outline the differences. In the second part, travelling wave solutions of Richards equation with gravity and with hysteresis in both the capillary pressure and relative permeability will be discussed. It will be explained why such solutions oscillate in space-time and how they behave as the hysteresis regularization vanishes.

Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

Treesearch

Congsheng Fu; Guiling Wang; Michael L. Goulden; Russell L. Scott; Kenneth Bible; Zoe G. Cardon

2016-01-01

Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site...

Comparison of Measurement And Modeling Of Current Profile Changes Due To Neutral Bean Ion Redistribution During TAE Avalanches in NSTX

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

Darrow, Douglas

Brief "avalanches" of toroidal Alfven eigenmodes (TAEs) are observed in NSTX plasmas with several different n numbers simultaneously present. These affect the neutral beam ion distribution as evidenced by a concurrent drop in the neutron rate and, sometimes, beam ion loss. Guiding center orbit modeling has shown that the modes can transiently render portions of the beam ion phase space stochastic. The resulting redistribution of beam ions can also create a broader beam-driven current profile and produce other changes in the beam ion distribution function

Subsurface application enhances benefits of manure redistribution

USDA-ARS?s Scientific Manuscript database

Sustainable nutrient management requires redistribution of livestock manure from nutrient-excess areas to nutrient-deficit areas. Field experiments were conducted to assess agronomic and environmental effects of different poultry litter application methods (surface vs. subsurface) and timings (fall ...

Making C4 crops more water efficient under current and future climate: Tradeoffs between carbon gain and water loss

NASA Astrophysics Data System (ADS)

Srinivasan, V.; Pignon, C.

2017-12-01

C4 plants have a carbon concentrating mechanism that has evolved under historically low CO2 concentrations of around 200 ppm. However, increases in global CO2 concentrations in recent times (current CO2 concentrations are at 400 ppm and it is projected to be 550 ppm by mid-century) have diminished the relative advantage of C4 plants over C3 plants, which lack the expensive carbon concentrating machinery. Here we show by employing model simulations that under pre-historic CO2 concentrations, C4 plants are near optimal in their stomatal behavior and nitrogen partitioning between carbon concentrating machinery and carboxylation machinery, and they are significantly supra-optimal under current and future elevated CO2 concentrations. Model simulations performed at current CO2 concentrations of 400 ppm show that, under high light conditions, decreasing stomatal conductance by 20% results in a 15% increase in water use efficiency with negligible loss in photosynthesis. Under future elevated CO2 concentrations of 550 ppm, a 40% decrease in stomatal conductance produces a 35% increase in water use efficiency. Furthermore, stomatal closure is shown to be more effective in decreasing whole canopy transpiration compared to canopy top leaf transpiration, since shaded leaves are more supra-optimal than sunlit leaves. Model simulations for optimizing nitrogen distribution in C4 leaves show that under high light conditions, C4 plants over invest in carbon concentrating machinery and under invest in carboxylation machinery. A 20% redistribution in leaf nitrogen results in a 10% increase in leaf carbon assimilation without significant increases in transpiration under current CO2 concentrations of 400 ppm. Similarly, a 40% redistribution in leaf nitrogen results in a 15% increase in leaf carbon assimilation without significant increases in transpiration under future elevated CO2 concentrations of 550 ppm. Our model optimality simulations show that C4 leaves a supra optimal in their stomatal behavior and leaf nitrogen distribution and by decreasing stomatal conductance and redistributing nitrogen away from carbon concentrating mechanism and towards carboxylation machinery, we can significantly decrease transpiration and increase carbon assimilation thereby increasing water use efficiency.

Soil water content evaluation considering time-invariant spatial pattern and space-variant temporal change

NASA Astrophysics Data System (ADS)

Hu, W.; Si, B. C.

2013-10-01

Soil water content (SWC) varies in space and time. The objective of this study was to evaluate soil water content distribution using a statistical model. The model divides spatial SWC series into time-invariant spatial patterns, space-invariant temporal changes, and space- and time-dependent redistribution terms. The redistribution term is responsible for the temporal changes in spatial patterns of SWC. An empirical orthogonal function was used to separate the total variations of redistribution terms into the sum of the product of spatial structures (EOFs) and temporally-varying coefficients (ECs). Model performance was evaluated using SWC data of near-surface (0-0.2 m) and root-zone (0-1.0 m) from a Canadian Prairie landscape. Three significant EOFs were identified for redistribution term for both soil layers. EOF1 dominated the variations of redistribution terms and it resulted in more changes (recharge or discharge) in SWC at wetter locations. Depth to CaCO3 layer and organic carbon were the two most important controlling factors of EOF1, and together, they explained over 80% of the variations in EOF1. Weak correlation existed between either EOF2 or EOF3 and the observed factors. A reasonable prediction of SWC distribution was obtained with this model using cross validation. The model performed better in the root zone than in the near surface, and it outperformed conventional EOF method in case soil moisture deviated from the average conditions.

Particle sorting during sediment redistribution processes and the effect on 230Th-normalized mass accumulation rates

NASA Astrophysics Data System (ADS)

Marcantonio, Franco; Lyle, Mitchell; Ibrahim, Rami

2014-08-01

The 230Th method of determining mass accumulation rates (MARs) assumes that little to no fractionation occurs during sediment redistribution processes at the seafloor. We examine 230Th inventories in radiocarbon-dated multicore sediments from paired winnowed and focused sites at Cocos and Carnegie Ridges, Panama Basin. Radiocarbon-derived sand MARs, which likely represent the vertical rain of particles poorly transported by bottom currents, are similar at each of the paired sites but are different using 230Th normalization. 230Th-normalized MARs are about 60% lower at focused sites and likely underestimate vertical MARs, while the reverse is true for winnowed sites. We hypothesize that size fractionation occurs most frequently at lower current velocities, resulting in the coarse fraction being left behind and primarily the fine 230Th-rich grains being transported downslope. 230Th-normalization works well for recording fine-grained (detrital and opal), but not coarse-grained (carbonate), fluxes in regions that have undergone sediment redistribution.

Assessing income redistributive effect of health financing in Zambia.

PubMed

Mulenga, Arnold; Ataguba, John Ele-Ojo

2017-09-01

Ensuring an equitable health financing system is a major concern particularly in many developing countries. Internationally, there is a strong debate to move away from excessive reliance on direct out-of-pocket (OOP) spending towards a system that incorporates a greater element of risk pooling and thus affords greater protection for the poor. This is a major focus of the move towards universal health coverage (UHC). Currently, Zambia with high levels of poverty and income inequality is implementing health sector reforms for UHC through a social health insurance scheme. However, the way to identify the health financing mechanisms that are best suited to achieving this goal is to conduct empirical analysis and consider international evidence on funding universal health systems. This study assesses, for the first time, the progressivity of health financing and how it impacts on income inequality in Zambia. Three broad health financing mechanisms (general tax, a health levy and OOP spending) were considered. Data come from the 2010 nationally representative Zambian Living Conditions and Monitoring Survey with a sample size of 19,397 households. Applying standard methodologies, the findings show that total health financing in Zambia is progressive. It also leads to a statistically significant reduction in income inequality (i.e. a pro-poor redistributive effect estimated at 0.0110 (p < 0.01)). Similar significant pro-poor redistribution was reported for general taxes (0.0101 (p < 0.01)) and a health levy (0.0002 (p < 0.01)). However, the redistributive effect was not significant for OOP spending (0.0006). These results further imply that health financing redistributes income from the rich to the poor with a greater potential via general taxes. This points to areas where government policy may focus in attempting to reduce the high level of income inequality and to improve equity in health financing towards UHC in Zambia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of anthropogenic radioisotopes to estimate rates of soil redistribution by wind II: The potential for future use of 239+240Pu

NASA Astrophysics Data System (ADS)

Van Pelt, R. Scott; Ketterer, Michael E.

2013-06-01

In the previous paper, the use of soilborne 137Cs from atmospheric fallout to estimate rates of soil redistribution, particularly by wind, was reviewed. This method relies on the assumption that the source of 137Cs in the soil profile is from atmospheric fallout following the period of atmospheric weapons testing so that the temporal and, to a certain extent, the spatial patterns of 137Cs deposition are known. One of the major limitations occurs when local or regional sources of 137Cs contamination mask the pulse from global fallout, making temporal estimates of redistribution difficult or impossible. Like 137Cs, Pu exhibits strong affinity for binding to soil particle surfaces, and therefore, re-distribution of Pu inventory indicates inferred soil re-distribution. Compared to 137Cs, 239Pu and 240Pu offer several important advantages: (a) the two major Pu isotopes have much longer half-lives than 137Cs and (b) the ratio 240Pu/239Pu is used to examine whether the Pu is from stratospheric fallout. In this paper, we review the literature concerning Pu in soil and of current attempts to use this tracer to estimate rates of soil redistribution. We also present preliminary, unpublished data from a pilot study designed to test whether or not 239+240Pu can be used to estimate rates of soil redistribution by wind. Based on similarities of profile distribution and relative inventories between 137Cs measurements and 239+240Pu measurements of split samples from a series of fields with documented wind erosion histories, we conclude that 239+240Pu may well be the anthropogenic radioisotope of choice for future soil redistribution investigations.

Support for redistribution is shaped by compassion, envy, and self-interest, but not a taste for fairness.

PubMed

Sznycer, Daniel; Lopez Seal, Maria Florencia; Sell, Aaron; Lim, Julian; Porat, Roni; Shalvi, Shaul; Halperin, Eran; Cosmides, Leda; Tooby, John

2017-08-01

Why do people support economic redistribution? Hypotheses include inequity aversion, a moral sense that inequality is intrinsically unfair, and cultural explanations such as exposure to and assimilation of culturally transmitted ideologies. However, humans have been interacting with worse-off and better-off individuals over evolutionary time, and our motivational systems may have been naturally selected to navigate the opportunities and challenges posed by such recurrent interactions. We hypothesize that modern redistribution is perceived as an ancestral scene involving three notional players: the needy other, the better-off other, and the actor herself. We explore how three motivational systems-compassion, self-interest, and envy-guide responses to the needy other and the better-off other, and how they pattern responses to redistribution. Data from the United States, the United Kingdom, India, and Israel support this model. Endorsement of redistribution is independently predicted by dispositional compassion, dispositional envy, and the expectation of personal gain from redistribution. By contrast, a taste for fairness, in the sense of ( i ) universality in the application of laws and standards, or ( ii ) low variance in group-level payoffs, fails to predict attitudes about redistribution.

Support for redistribution is shaped by compassion, envy, and self-interest, but not a taste for fairness

PubMed Central

Lopez Seal, Maria Florencia; Sell, Aaron; Lim, Julian; Porat, Roni; Halperin, Eran; Cosmides, Leda; Tooby, John

2017-01-01

Why do people support economic redistribution? Hypotheses include inequity aversion, a moral sense that inequality is intrinsically unfair, and cultural explanations such as exposure to and assimilation of culturally transmitted ideologies. However, humans have been interacting with worse-off and better-off individuals over evolutionary time, and our motivational systems may have been naturally selected to navigate the opportunities and challenges posed by such recurrent interactions. We hypothesize that modern redistribution is perceived as an ancestral scene involving three notional players: the needy other, the better-off other, and the actor herself. We explore how three motivational systems—compassion, self-interest, and envy—guide responses to the needy other and the better-off other, and how they pattern responses to redistribution. Data from the United States, the United Kingdom, India, and Israel support this model. Endorsement of redistribution is independently predicted by dispositional compassion, dispositional envy, and the expectation of personal gain from redistribution. By contrast, a taste for fairness, in the sense of (i) universality in the application of laws and standards, or (ii) low variance in group-level payoffs, fails to predict attitudes about redistribution. PMID:28716928

Report: EPA Could Improve Its Redistribution of Superfund Payments to Specific Sites

EPA Pesticide Factsheets

Report #2006-P-00027, July 31, 2006. EPA did not make timely redistributions of Superfund coop agreement, interagency agreement, and small purchase payments from the general site identifier “WQ” to the specific Superfund sites or other site identifiers.

An efficient and guaranteed stable numerical method for continuous modeling of infiltration and redistribution with a shallow dynamic water table

NASA Astrophysics Data System (ADS)

Lai, Wencong; Ogden, Fred L.; Steinke, Robert C.; Talbot, Cary A.

2015-03-01

We have developed a one-dimensional numerical method to simulate infiltration and redistribution in the presence of a shallow dynamic water table. This method builds upon the Green-Ampt infiltration with Redistribution (GAR) model and incorporates features from the Talbot-Ogden (T-O) infiltration and redistribution method in a discretized moisture content domain. The redistribution scheme is more physically meaningful than the capillary weighted redistribution scheme in the T-O method. Groundwater dynamics are considered in this new method instead of hydrostatic groundwater front. It is also computationally more efficient than the T-O method. Motion of water in the vadose zone due to infiltration, redistribution, and interactions with capillary groundwater are described by ordinary differential equations. Numerical solutions to these equations are computationally less expensive than solutions of the highly nonlinear Richards' (1931) partial differential equation. We present results from numerical tests on 11 soil types using multiple rain pulses with different boundary conditions, with and without a shallow water table and compare against the numerical solution of Richards' equation (RE). Results from the new method are in satisfactory agreement with RE solutions in term of ponding time, deponding time, infiltration rate, and cumulative infiltrated depth. The new method, which we call "GARTO" can be used as an alternative to the RE for 1-D coupled surface and groundwater models in general situations with homogeneous soils with dynamic water table. The GARTO method represents a significant advance in simulating groundwater surface water interactions because it very closely matches the RE solution while being computationally efficient, with guaranteed mass conservation, and no stability limitations that can affect RE solvers in the case of a near-surface water table.

A scale-invariant cellular-automata model for distributed seismicity

NASA Technical Reports Server (NTRS)

Barriere, Benoit; Turcotte, Donald L.

1991-01-01

In the standard cellular-automata model for a fault an element of stress is randomly added to a grid of boxes until a box has four elements, these are then redistributed to the adjacent boxes on the grid. The redistribution can result in one or more of these boxes having four or more elements in which case further redistributions are required. On the average added elements are lost from the edges of the grid. The model is modified so that the boxes have a scale-invariant distribution of sizes. The objective is to model a scale-invariant distribution of fault sizes. When a redistribution from a box occurs it is equivalent to a characteristic earthquake on the fault. A redistribution from a small box (a foreshock) can trigger an instability in a large box (the main shock). A redistribution from a large box always triggers many instabilities in the smaller boxes (aftershocks). The frequency-size statistics for both main shocks and aftershocks satisfy the Gutenberg-Richter relation with b = 0.835 for main shocks and b = 0.635 for aftershocks. Model foreshocks occur 28 percent of the time.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

NASA Astrophysics Data System (ADS)

Parke, E.; Anderson, J. K.; Brower, D. L.; Den Hartog, D. J.; Ding, W. X.; Johnson, C. A.; Lin, L.

2016-05-01

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm with neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q0 by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].

Radiation detector using a bulk high T.sub.c superconductor

DOEpatents

Artuso, Joseph F.; Franks, Larry A.; Hull, Kenneth L.; Symko, Orest G.

1993-01-01

A radiation detector (10) is provided, wherein a bulk high T.sub.c superconducting sample (11) is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil (12) which is coupled by an input coil (15) to an rf SQUID (16).

Radiation detector using a bulk high T[sub c] superconductor

DOEpatents

Artuso, J.F.; Franks, L.A.; Hull, K.L.; Symko, O.G.

1993-12-07

A radiation detector is provided, wherein a bulk high T[sub c] superconducting sample is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil which is coupled by an input coil to an rf SQUID. 4 figures.

Plasma density evolution in plasma opening switch obtained by a time-resolved sensitive He-Ne interferometer

NASA Astrophysics Data System (ADS)

Chen, Lin; Ren, Jing; Guo, Fan; Zhou, LiangJi; Li, Ye; He, An; Jiang, Wei

2014-03-01

To understand the formation process of vacuum gap in coaxial microsecond conduction time plasma opening switch (POS), we have made measurements of the line-integrated plasma density during switch operation using a time-resolved sensitive He-Ne interferometer. The conduction current and conduction time in experiments are about 120 kA and 1 μs, respectively. As a result, more than 85% of conduction current has been transferred to an inductive load with rise time of 130 ns. The radial dependence of the density is measured by changing the radial location of the line-of-sight for shots with the same nominal POS parameters. During the conduction phase, the line-integrated plasma density in POS increases at all radial locations over the gun-only case by further ionization of material injected from the guns. The current conduction is observed to cause a radial redistribution of the switch plasma. A vacuum gap forms rapidly in the plasma at 5.5 mm from the center conductor, which is consistent with the location where magnetic pressure is the largest, allowing current to be transferred from the POS to the load.

Fiscal Impacts and Redistributive Effects of the New Federalism on Michigan School Districts.

ERIC Educational Resources Information Center

Kearney, C. Philip; Kim, Taewan

1990-01-01

The fiscal impacts and redistribution effects of the recently enacted (1981) federal education block grant on 525 elementary and secondary school districts in Michigan were examined using a quasi-experimental time-series design and multiple regression and analysis of covariance techniques. Implications of changes in federal policy are discussed.…

HYDRAULIC REDISTRIBUTION OF SOIL WATER DURING SUMMER DROUGHT IN TWO CONTRASTING PACIFIC NORTHWEST CONIFEROUS FORESTS

EPA Science Inventory

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status at multiple depths and root sap flow during droughted conditions in a dry ponderosa pine ecosystem and a moist Doug...

Distribution of Region 1 and 2 currents in the quietand substorm time plasma sheetfrom THEMIS observations

NASA Astrophysics Data System (ADS)

Liu, J.; Angelopoulos, V.; Chu, X.; McPherron, R. L.

2016-12-01

Although Earth's Region 1 and 2 currents are related to activities such as substorm initiation, their magnetospheric origin remains unclear. Utilizing the triangular configuration of THEMIS probes at 8-12 RE downtail, we seek the origin of nightside Region 1 and 2 currents. The triangular configuration allows a curlometer-like technique which do not rely on active-time boundary crossings, so we can examine the current distribution in quiet times as well as active times. Our statistical study reveals that both Region 1 and 2 currents exist in the plasma sheet during quiet and active times. Especially, this is the first unequivocal, in-situ evidence of the existence of Region 2 currents in the plasma sheet. Farther away from the neutral sheet than the Region 2 currents lie the Region 1 currents which extend at least to the plasma sheet boundary layer. At geomagnetic quiet times, the separation between the two currents is located 2.5 RE from the neutral sheet. These findings suggest that the plasma sheet is a source of Region 1 and 2 currents regardless of geomagnetic activity level. During substorms, the separation between Region 1 and 2 currents migrates toward (away from) the neutral sheet as the plasma sheet thins (thickens). This migration indicates that the deformation of Region 1 and 2 currents is associated with redistribution of FAC sources in the magnetotail. In some substorms when the THEMIS probes encounter a dipolarization, a substorm current wedge (SCW) can be inferred from our technique, and it shows a distinctively larger current density than the pre-existing Region 1 currents. This difference suggests that the SCW is not just an enhancement of the pre-existing Region 1 current; the SCW and the Region 1 currents have different sources.

The Ultimate Spitzer Phase Curve Survey: Cross-Planetary Comparison of Heat-Redistribution Efficiencies

NASA Astrophysics Data System (ADS)

Fraine, Jonathan D.; Stevenson, Kevin; Bean, Jacob; Deming, Drake; Fortney, Jonathan; Kataria, Tiffany; Kempton, Eliza; Lewis, Nikole K.; Line, Michael; Morley, Caroline; Rauscher, Emily; Showman, Adam; Feng, Katherina

2018-01-01

Exoplanet phase curves provide a wealth of information about exoplanet atmospheres, including longitudinal constraints on atmospheric composition, thermal structure, and energy transport, that continue to open new doors of scientific inquiry and propel future investigations. The measured heat redistribution efficiency (or ability to transport energy from a planet's highly-irradiated dayside to its eternally-dark nightside) shows considerable variation between exoplanets. Theoretical models predict a correlation between heat redistribution efficiency and planet temperature; however, the latest results are inconsistent with current predictions from 3D atmospheric simulations. We will present preliminary results from a 660-hour Spitzer phase curve survey program that targeted six short-period extrasolar planets. By comparing short periods exoplanets over a range of equilibrium temperatures, we can begin to disentangle the effects of planetary rotation and energy budget on a planet's thermal properties. We will discuss how the measured planet temperature and rotation rate affect the heat redistribution efficiencies, examine trends in the phase curve peak offset, and discuss cloud coverage constraints. Our Spitzer observations will provide valuable information for predicting and interpreting future, JWST-era observations.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

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

Parke, E.; Department of Physics, University of Wisconsin-Madison 1150 University Ave., Madison, Wisconsin 53706; Anderson, J. K.

2016-05-15

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm withmore » neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q{sub 0} by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].« less

Sediment Dynamics in Shallow Tidal Landscapes: The Role of Wind Waves and Tidal Currents

NASA Astrophysics Data System (ADS)

Carniello, L.; D'Alpaos, A.

2014-12-01

A precise description of sediment dynamics (resuspension and re-distribution of sediments) is crucial when investigating the long term evolution of the different morphological entities characterizing tidal landscapes. It has been demonstrated that wind waves are the main responsible for sediment resuspension in shallow micro-tidal lagoons where tidal currents, which produce shear stresses large enough to carry sediments into suspension only within the main channels, are mainly responsible for sediment redistribution. A mathematical model has been developed to describe sediment entrainment, transport and deposition due to the combined effect of tidal currents and wind waves in shallow lagoons considering both cohesive and non-cohesive sediments. The model was calibrated and tested using both in situ point observations and turbidity maps obtained analyzing satellite images. Once calibrated the model can integrate the high temporal resolution of point observations with the high spatial resolution of remote sensing, overcoming the intrinsic limitation of these two types of observations. The model was applied to the specific test case of the Venice lagoon simulating an entire year (2005) which was shown to be a "representative" year for wind and tide characteristics. The time evolution of the computed total bottom shear stresses (BSS) and suspended sediment concentration (SSC) was analyzed on the basis of a "Peaks Over Threshold" method once a critical value for shear stress and turbidity were chosen. The analyses of the numerical results enabled us to demonstrate that resuspension events can be modeled as marked Poisson processes: interarrival time, intensity of peak excesses and duration being exponentially distributed random variable. The probability distributions of the interarrival time of overthreshold exceedances in both BSS and SSC as well as their intensity and duration can be used in long-term morphodynamic studies to generate synthetic series statistically equivalent to real sequences through which MonteCarlo realizations of relevant morphological evolutions can be computed.

General Revenue Financing of Medicare: Who Will Bear the Burden?

PubMed Central

Johnson, Janet L.; Long, Stephen H.

1982-01-01

Two recent national advisory committees on Social Security recommended major shifts in Medicare financing to preserve the financial viability of the Social Security trust funds. This paper estimates the income redistribution consequences of the two proposals, in contrast to current law, using a micro-simulation model of taxes and premiums. These estimates show that while the current Medicare financing package is mildly progressive, the new proposals would substantially increase income redistribution under the program. Two insights provided by separate estimates, for families headed by the elderly (persons age 65 or over) versus those headed by the non-elderly, are: 1) the surprisingly large Medicare tax burdens on families headed by the elderly under the current financing package of payroll taxes, general revenues, and enrollee premiums; and 2) the substantial increases in these burdens under proposed shifts toward increased general revenue financing. PMID:10309601

Hydraulic redistribution of soil water during summer drought in two contrasting Pacific Northwest coniferous forests.

Treesearch

J. Renee Brooks; Frederick C. Meinzer; Rob Coulombe; Jillian Gregg

2002-01-01

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status and multiple depths and root sap flow under drought conditions in a dry ponderosa pine (Pinus ponderosa Dougl. ex Laws) ecosystem and in a moist Douglas-fir (Pseudotsuga...

Predicting the fate of sediment and pollutants in river floodplains.

PubMed

Malmon, Daniel V; Dunne, Thomas; Reneau, Steven L

2002-05-01

Geological processes such as erosion and sedimentation redistribute toxic pollutants introduced to the landscape by mining, agriculture, weapons development, and other human activities. A significant portion of these contaminants is insoluble, adsorbing to soils and sediments after being released. Geologists have long understood that much of this sediment is stored in river floodplains, which are increasingly recognized as important nonpoint sources of pollution in rivers. However, the fate of contaminated sediment has generally been analyzed using hydrodynamic models of in-channel processes, ignoring particle exchange with the floodplain. Here, we present a stochastic theory of sediment redistribution in alluvial valley floors that tracks particle-bound pollutants and explicitly considers sediment storage within floodplains. We use the theory to model the future redistribution and radioactive decay of 137Cs currently stored on sediment in floodplains at the Los Alamos National Laboratory (LANL) in New Mexico. Model results indicate that floodplain storage significantly reduces the rate of sediment delivery from upper Los Alamos Canyon, allowing 50% of the 137Cs currently residing in the valley floor to decay radioactively before leaving LANL. A sensitivity analysis shows that the rate of sediment overturn in the valley (and hence, the total amount of radioactive 137Cs predicted to leave LANL) is significantly controlled by the rate of sediment exchange with the floodplain. Our results emphasize that flood plain sedimentation and erosion processes can strongly influence the redistribution of anthropogenic pollutants in fluvial environments. We introduce a new theoretical framework for examining this interaction, which can provide a scientific basis for decision-making in a wide range of river basin management scenarios.

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

Orange, N. Brice; Chesny, David L.; Gendre, Bruce

Solar variability investigations that include magnetic energy coupling are paramount to solving many key solar/stellar physics problems, particularly for understanding the temporal variability of magnetic energy redistribution and heating processes. Using three years of observations from the Solar Dynamics Observatory ’ s Atmospheric Imaging Assembly and Heliosemic Magnetic Imager, we measured radiative and magnetic fluxes from gross features and at full-disk scales, respectively. Magnetic energy coupling analyses support radiative flux descriptions via the plasma heating connectivity of dominant (magnetic) and diffuse components, specifically of the predominantly closed-field corona. Our work shows that this relationship favors an energetic redistribution efficiency acrossmore » large temperature gradients, and potentially sheds light on the long-standing issue of diffuse unresolved low corona emission. The close connection between magnetic energy redistribution and plasma conditions revealed by this work lends significant insight into the field of stellar physics, as we have provided possible means for probing distant sources in currently limited and/or undetectable radiation distributions.« less

Studies of water storage and other contributions to changes in the rotation of the Earth

NASA Technical Reports Server (NTRS)

Wilson, Clark R.

1991-01-01

The effects were determined of the global redistribution of water mass on various geodetic observables, especially polar motion, and complementary observables such as geodetic satellite positions. The effect of water mass redistribution has been and continues to be less well known and more difficult to observe than effects of air mass distribution, yet the water contribution is potentially significant over a large range of periods. The current understanding is reviewed of the contribution of polar drift, decadal polar motion, Chandler and annual wobbles, and higher frequency polar motion, as determined through the efforts of the funded work within the NASA Crustal Dynamics Project, and in the context of the general literature on the subject. Water mass redistribution is either demonstrably important to the excitation of each of these, or is probably important given a lack of other likely excitation sources.

First Results From The Ultimate Spitzer Phase Curve Survey

NASA Astrophysics Data System (ADS)

Stevenson, Kevin B.; Bean, Jacob; Deming, Drake; Desert, Jean-Michel; Fortney, Jonathan J.; Kataria, Tiffany; Kempton, Eliza; Lewis, Nikole; Line, Michael R.; Morley, Caroline; Rauscher, Emily; Showman, Adam P.

2017-10-01

Exoplanet phase curves provide a wealth of information about exoplanet atmospheres, including longitudinal constraints on atmospheric composition, thermal structure, and energy transport, that continue to open new doors of scientific inquiry and propel future investigations. The measured heat redistribution efficiency (or ability to transport energy from a planet's highly-irradiated dayside to its eternally-dark nightside) shows considerable variation between exoplanets. Theoretical models predict a correlation between heat redistribution efficiency and planet temperature; however, the latest results are inconsistent with current predictions. We will present first results from a 660-hour Spitzer phase curve survey program that is targeting six short-period extrasolar planets. We will compare the measured heat redistribution efficiencies with planet temperature and rotation rate, examine trends in the phase curve peak offset, and discuss cloud coverage constraints. We will conclude with how to move forward with phase curve observations in the era of JWST.

Simulations of snow distribution and hydrology in a mountain basin

USGS Publications Warehouse

Hartman, Melannie D.; Baron, Jill S.; Lammers, Richard B.; Cline, Donald W.; Band, Larry E.; Liston, Glen E.; Tague, Christina L.

1999-01-01

We applied a version of the Regional Hydro-Ecologic Simulation System (RHESSys) that implements snow redistribution, elevation partitioning, and wind-driven sublimation to Loch Vale Watershed (LVWS), an alpine-subalpine Rocky Mountain catchment where snow accumulation and ablation dominate the hydrologic cycle. We compared simulated discharge to measured discharge and the simulated snow distribution to photogrammetrically rectified aerial (remotely sensed) images. Snow redistribution was governed by a topographic similarity index. We subdivided each hillslope into elevation bands that had homogeneous climate extrapolated from observed climate. We created a distributed wind speed field that was used in conjunction with daily measured wind speeds to estimate sublimation. Modeling snow redistribution was critical to estimating the timing and magnitude of discharge. Incorporating elevation partitioning improved estimated timing of discharge but did not improve patterns of snow cover since wind was the dominant controller of areal snow patterns. Simulating wind-driven sublimation was necessary to predict moisture losses.

Physical mechanisms of self-organization and formation of current patterns in gas discharges of the Townsend and glow types

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

Raizer, Yu. P.; Mokrov, M. S.

The paper discusses current filamentation and formation of current structures (in particular, hexagonal current patterns) in discharges of the Townsend and glow types. The aim of the paper, which is in part a review, is to reveal basic reasons for formation of current patterns in different cases, namely, in dielectric barrier discharge, discharge with semiconductor cathode, and micro-discharge between metallic electrodes. Pursuing this goal, we give a very brief review of observations and discuss only those theoretical, computational, and experimental papers that shed light on the physical mechanisms involved. The mechanisms are under weak currents—the thermal expansion of the gasmore » as a result of Joule heating; under enhanced currents—the electric field and ionization rate redistribution induced by space charge. Both mechanisms lead to instability of the homogeneous discharges. In addition, we present new results of numerical simulations of observed short-living current filaments which are chaotic in space and time.« less

Modelled hydraulic redistribution by sunflower (Helianthus annuus L.) matches observed data only after including night-time transpiration.

PubMed

Neumann, Rebecca B; Cardon, Zoe G; Teshera-Levye, Jennifer; Rockwell, Fulton E; Zwieniecki, Maciej A; Holbrook, N Michele

2014-04-01

The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical and ecological consequences of HR depend on the amount of redistributed water, whereas the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two ecotypes of sunflower (Helianthus annuus L.) in split-pot experiments, we examined how well the widely used HR modelling formulation developed by Ryel et al. matched experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive night-time transpiration, and although over the last decade it has become more widely recognized that night-time transpiration occurs in multiple species and many ecosystems, the original Ryel et al. formulation does not include the effect of night-time transpiration on HR. We developed and added a representation of night-time transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and night-time stomatal behaviour changed, both influencing HR. © 2013 John Wiley & Sons Ltd.

77 FR 29955 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Trawl...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... redistributed to other QS permit owners in proportion to their current QS and IBQ holdings. Delaying QS... allocations. The proposed process of ``holding'' back sufficient QP is similar to the current process of...); Sperm whales (Physter macrocephalus); Southern Resident killer whales (Orcinus orca); Guadalupe fur...

Automated graphic image generation system for effective representation of infectious disease surveillance data.

PubMed

Inoue, Masashi; Hasegawa, Shinsaku; Suyama, Akihiko; Meshitsuka, Shunsuke

2003-11-01

Infectious disease surveillance schemes have been established to detect infectious disease outbreak in the early stages, to identify the causative viral strains, and to rapidly assess related morbidity and mortality. To make a scheme function well, two things are required. Firstly, it must have sufficient sensitivity and be timely to guarantee as short a delay as possible from collection to redistribution of information. Secondly, it must provide a good representation of the results of the surveillance. To do this, we have developed a database system that can redistribute the information via the Internet. The feature of this system is to automatically generate the graphic images based on the numerical data stored in the database by using Hypertext Preprocessor (PHP) script and Graphics Drawing (GD) library. It dynamically displays the information as a map or bar chart as well as a numerical impression according to the real time demand of the users. This system will be a useful tool for medical personnel and researchers working on infectious disease problems and will save significant time in the redistribution of information.

Fiscal decentralization in the Italian NHS: what happens to interregional redistribution?

PubMed

Ferrario, Caterina; Zanardi, Alberto

2011-04-01

This paper explores how pressures for an increased decentralization of taxing powers to sub-national governments may affect the degree of income redistribution across regional territories accomplished by the Italian NHS. In Italy, political responsibilities for health care are decentralized to regional governments, but the central government retains a critical role in ensuring all citizens uniform access to health services. To this end the central government runs an expenditure needs equalizing system to top up regional governments own resources. However, this system is currently put under question by strong political pressures calling for a weakening of central government involvement. Applying a well developed econometric approach we find that the NHS currently reduces interregional differences in per-capita income by about 7% of GDP. A reform of the NHS in terms of a reduction of expenditure standards produces a weakening of redistribution across jurisdictions, the size of which crucially depends on the financing arrangements of health care that will be actually adopted. We conclude that the decentralization of the NHS would give rise to relevant policy issues concerning in particular the different health care spending possibilities across regions and the impact on the interregional mobility of patients. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Electromagnetic Field Redistribution in Metal Nanoparticle on Graphene.

PubMed

Li, Keke; Liu, Anping; Wei, Dapeng; Yu, Keke; Sun, Xiaonan; Yan, Sheng; Huang, Yingzhou

2018-04-25

Benefiting from the induced image charge on metal film, the light energy is confined on a film surface under metal nanoparticle dimer, which is called electromagnetic field redistribution. In this work, electromagnetic field distribution of metal nanoparticle monomer or dimer on graphene is investigated through finite-difference time-domain method. The results point out that the electromagnetic field (EM) redistribution occurs in this nanoparticle/graphene hybrid system at infrared region where light energy could also be confined on a monolayer graphene surface. Surface charge distribution was analyzed using finite element analysis, and surface-enhanced Raman spectrum (SERS) was utilized to verify this phenomenon. Furthermore, the data about dielectric nanoparticle on monolayer graphene demonstrate this EM redistribution is attributed to strong coupling between light-excited surface charge on monolayer graphene and graphene plasmon-induced image charge on dielectric nanoparticle surface. Our work extends the knowledge of monolayer graphene plasmon, which has a wide range of applications in monolayer graphene-related film.

Quantum dynamics of the intramolecular vibrational energy redistribution in OCS: From localization to quasi-thermalization

NASA Astrophysics Data System (ADS)

Pérez, J. B.; Arce, J. C.

2018-06-01

We report a fully quantum-dynamical study of the intramolecular vibrational energy redistribution (IVR) in the electronic ground state of carbonyl sulfide, which is a prototype of an isolated many-body quantum system with strong internal couplings and non-Rice-Ramsperger-Kassel-Marcus (RRKM) behavior. We pay particular attention to the role of many-body localization and the approach to thermalization, which currently are topics of considerable interest, as they pertain to the very foundations of statistical mechanics and thermodynamics. We employ local-mode (valence) coordinates and consider initial excitations localized in one local mode, with energies ranging from low to near the dissociation threshold, where the classical dynamics have been shown to be chaotic. We propagate the nuclear wavepacket on the potential energy surface by means of the numerically exact multiconfiguration time-dependent Hartree method and employ mean local energies, time-dependent and time-averaged populations in quantum number space, energy distributions, entanglement entropies, local population distributions, microcanonical averages, and dissociation probabilities, as diagnostic tools. This allows us to identify a continuous localization → delocalization transition in the energy flow, associated with the onset of quantum chaos, as the excitation energy increases up to near the dissociation threshold. Moreover, we find that at this energy and ˜1 ps the molecule nearly thermalizes. Furthermore, we observe that IVR is so slow that the molecule begins to dissociate well before such quasi-thermalization is complete, in accordance with earlier classical-mechanical predictions of non-RRKM behavior.

Quantum dynamics of the intramolecular vibrational energy redistribution in OCS: From localization to quasi-thermalization.

PubMed

Pérez, J B; Arce, J C

2018-06-07

We report a fully quantum-dynamical study of the intramolecular vibrational energy redistribution (IVR) in the electronic ground state of carbonyl sulfide, which is a prototype of an isolated many-body quantum system with strong internal couplings and non-Rice-Ramsperger-Kassel-Marcus (RRKM) behavior. We pay particular attention to the role of many-body localization and the approach to thermalization, which currently are topics of considerable interest, as they pertain to the very foundations of statistical mechanics and thermodynamics. We employ local-mode (valence) coordinates and consider initial excitations localized in one local mode, with energies ranging from low to near the dissociation threshold, where the classical dynamics have been shown to be chaotic. We propagate the nuclear wavepacket on the potential energy surface by means of the numerically exact multiconfiguration time-dependent Hartree method and employ mean local energies, time-dependent and time-averaged populations in quantum number space, energy distributions, entanglement entropies, local population distributions, microcanonical averages, and dissociation probabilities, as diagnostic tools. This allows us to identify a continuous localization → delocalization transition in the energy flow, associated with the onset of quantum chaos, as the excitation energy increases up to near the dissociation threshold. Moreover, we find that at this energy and ∼1 ps the molecule nearly thermalizes. Furthermore, we observe that IVR is so slow that the molecule begins to dissociate well before such quasi-thermalization is complete, in accordance with earlier classical-mechanical predictions of non-RRKM behavior.

Precision increase in electric drive speed loop of robotic complexes and process lines

NASA Astrophysics Data System (ADS)

Tulegenov, E.; Imanova, A. A.; Platonov, V. V.

2018-05-01

The article presents the principles of synthesis of control structures for highprecision electric drives of robotic complexes and manipulators. It has been theoretically shown and experimentally confirmed that improved characteristics of speed maintenance in the zone of significant overloads are achieved in systems of series excitation. They are achieved due to the redistribution of control signals both in the zone of setting the armature current and in the excitation currents. At the same time, the characteristic of the electromagnetic torque becomes linear because the demagnetizing effect of the armature response is compensated by the setting of the excitation current. It is recommended in those cases when it is necessary to extend the range of speed control with a significant reduction in load to apply structures with two-zone speed control. The regulation of the weakening of the excitation flow is more convenient as a function of the voltage in the armature windings.

Heat-induced redistribution of surface oxide in uranium

NASA Astrophysics Data System (ADS)

Swissa, Eli; Shamir, Noah; Mintz, Moshe H.; Bloch, Joseph

1990-09-01

The redistribution of oxygen and uranium metal at the vicinity of the metal-oxide interface of native and grown oxides due to vacuum thermal annealing was studied for uranium and uranium-chromium alloy using Auger depth profiling and metallographic techniques. It was found that uranium metal is segregating out through the uranium oxide layer for annealing temperatures above 450°C. At the same time the oxide is redistributed in the metal below the oxide-metal interface in a diffusion like process. By applying a diffusion equation of a finite source, the diffusion coefficients for the process were obtained from the oxygen depth profiles measured for different annealing times. An Arrhenius like behavior was found for the diffusion coefficient between 400 and 800°C. The activation energy obtained was Ea = 15.4 ± 1.9 kcal/mole and the pre-exponential factor, D0 = 1.1 × 10 -8cm2/ s. An internal oxidation mechanism is proposed to explain the results.

Simplified data assimilation for simulating wet deposition distribution of radioactive materials in FDNPP accident

NASA Astrophysics Data System (ADS)

Saya, A.; Yoshikane, T.; Chang, E. C.; Yoshimura, K.

2015-12-01

Due to the massive earthquakes and tsunami on March 11th 2011 in Eastern Japan, Fukushima Daiichi Nuclear Power Plant (FDNPP) was severely damaged. Radioactive materials were released and spread out by atmospheric advection-diffusion. Especially on March 21 - 23th when precipitation was observed, "hotspot" where the high concentration was detected locally. This area was formed in the metropolitan area in Kanto region. Thus, pollution at water treatment plants because of the deposition became a concern. Therefore, the reliable information of the hotspot is expected. Currently, atmospheric transport simulations by numerical models are developed for reproduction of the distribution. However, there are some uncertainties in the simulations. In the case of hotspot, accuracy of simulated precipitation have to be well considered because the hotspot seemed to be formed by wet deposition. We modified the stable isotope mode of Regional Spectral Model (IsoRSM) to enable to simulate the transport of the radioactive tracers, namely 131I and 137Cs, by including the dry and wet deposition processes. As the simplified data assimilation, simulated precipitation was replaced with Radar-AMeDAS precipitation data (RAP). RAP was assimilated in the post-process, after running simulations, to redistribute wet deposition of 137Cs. The ratio of 137Cs deposited from the cumulative vertical column with precipitation in the domain was not changed, however its pattern was redistributed corresponding with RAP and simulated concentration. As a result, the redistributed wet deposition was within factor 10 to 2 compared with the fallout data in Kanto region, and further data assimilation would be contributed. In addition, we found that due to the arrival time of the plume in the morning on 21st and the border time of daily observation data of fallout, validation result might be worse even though hourly distributions are well simulated.

Emission current formation in plasma electron emitters

NASA Astrophysics Data System (ADS)

Gruzdev, V. A.; Zalesski, V. G.

2010-12-01

A model of the plasma electron emitter is considered, in which the current redistribution over electrodes of the emitter gas-discharge structure and weak electric field formation in plasma are taken into account as functions of the emission current. The calculated and experimental dependences of the switching parameters, extraction efficiency, and strength of the electric field in plasma on the accelerating voltage and geometrical sizes of the emission channel are presented.

A manpower calculus: the implications of SUO fellowship expansion on oncologic surgeon case volumes.

PubMed

See, William A

2014-01-01

Society of Urologic Oncology (SUO)-accredited fellowship programs have undergone substantial expansion. This study developed a mathematical model to estimate future changes in urologic oncologic surgeon (UOS) manpower and analyzed the effect of those changes on per-UOS case volumes. SUO fellowship program directors were queried as to the number of positions available on an annual basis. Current US UOS manpower was estimated from the SUO membership list. Future manpower was estimated on an annual basis by linear senescence of existing manpower combined with linear growth of newly trained surgeons. Case-volume estimates for the 4 surgical disease sites (prostate, kidney/renal pelvis, bladder, and testes) were obtained from the literature. The future number of major cases was determined from current volumes based upon the US population growth rates and the historic average annual change in disease incidence. Two models were used to predict future per-UOS major case volumes. Model 1 assumed the current distribution of cases between nononcologic surgeons and UOS would continue. Model 2 assumed a progressive redistribution of cases over time such that in 2043 100% of major urologic cancer cases would be performed by UOSs. Over the 30-year period to "manpower steady-state" SUO-accredited UOSs practicing in the United States have the potential to increase from approximately 600 currently to 1,650 in 2043. During this interval, case volumes are predicted to change 0.97-, 2.4-, 1.1-, and 1.5-fold for prostatectomy, nephrectomy, cystectomy, and retroperitoneal lymph node dissection, respectively. The ratio of future to current total annual case volumes is predicted to be 0.47 and 0.9 for models 1 and 2, respectively. The number of annual US practicing graduates necessary to achieve a future to current case-volume ratio greater than 1 is 25 and 49 in models 1 and 2, respectively. The current number of SUO fellowship trainees has the potential to decrease future per-UOS case volumes relative to current levels. Redistribution of existing case volume or a decrease in the annual number of trainees or both would be required to insure sufficient surgical volumes for skill maintenance and optimal patient outcomes. Published by Elsevier Inc.

The tetravalent organic cation spermine causes the gating of the IRK1 channel expressed in murine fibroblast cells.

PubMed Central

Ishihara, K; Hiraoka, M; Ochi, R

1996-01-01

1. The activation kinetics of the IRK1 channel stably expressed in L cells (a murine fibroblast cell line) were studied under the whole-cell voltage clamp. Without polyamines or Mg2+ in the pipettes, inward currents showed an exponential activation on hyperpolarization. The steep inward rectification of the currents around the reversal potential (Erev) could be described by the open-close transition of the channel with first-order kinetics. 2. When the tetravalent organic cation spermine (Spm) was added in the pipettes, the activation kinetics changed; this was explicable by the increase in the closing rate constant. The activation of the currents observed without Spm or Mg2+ in the pipettes was ascribed to the unblocking of the 'endogenous-Spm block'. 3. In the presence of the divalent cation putrescine (Put) or of Mg2+ in the pipettes, a different non-conductive state suppressed the outward currents on depolarization; the channels instantaneously changed to the open state on repolarization. As the depolarization was prolonged, this non-conductive state was replaced by the non-conductive state that shows an exponential activation on repolarization. This phenomenon was attributed to the redistribution of the channels from the Put- or Mg(2+)-blocked state to the 'endogenous Spm-blocked state' during depolarization. 4. In the presence of the trivalent cation spermidine (Spd) in the pipettes, two different non-conductive states occurred, showing a faster and a slower activation on repolarization. The rectification around Erev was mainly due to the non-conductive state showing a faster activation, which appeared to be the Spd-blocked state. During depolarization, redistribution of the channels to the 'endogenous Spm-blocked state' also occurred. 5. In the presence of Spd, Put or Mg2+ in the pipettes, the voltage dependence of the activation time constant reflecting the unblocking of the 'endogenous Spm' was shifted in the hyperpolarizing direction. 6. Our results suggest that the 'intrinsic gating' that shows the time-dependent activation on repolarization, and that is responsible for the inward rectification around Erev, reflects the blocking kinetics of the tetravalent Spm. PMID:8866861

Revisiting the horizontal redistribution of water in soils: Experiments and numerical modeling.

PubMed

Zhuang, L; Hassanizadeh, S M; Kleingeld, P J; van Genuchten, M Th

2017-09-01

A series of experiments and related numerical simulations were carried out to study one-dimensional water redistribution processes in an unsaturated soil. A long horizontal Plexiglas box was packed as homogenously as possible with sand. The sandbox was divided into two sections using a very thin metal plate, with one section initially fully saturated and the other section only partially saturated. Initial saturation in the dry section was set to 0.2, 0.4, or 0.6 in three different experiments. Redistribution between the wet and dry sections started as soon as the metal plate was removed. Changes in water saturation at various locations along the sandbox were measured as a function of time using a dual-energy gamma system. Also, air and water pressures were measured using two different kinds of tensiometers at various locations as a function of time. The saturation discontinuity was found to persist during the entire experiments, while observed water pressures were found to become continuous immediately after the experiments started. Two models, the standard Richards equation and an interfacial area model, were used to simulate the experiments. Both models showed some deviations between the simulated water pressures and the measured data at early times during redistribution. The standard model could only simulate the observed saturation distributions reasonably well for the experiment with the lowest initial water saturation in the dry section. The interfacial area model could reproduce observed saturation distributions of all three experiments, albeit by fitting one of the parameters in the surface area production term.

Zone plate method for electronic holographic display using resolution redistribution technique.

PubMed

Takaki, Yasuhiro; Nakamura, Junya

2011-07-18

The resolution redistribution (RR) technique can increase the horizontal viewing-zone angle and screen size of electronic holographic display. The present study developed a zone plate method that would reduce hologram calculation time for the RR technique. This method enables calculation of an image displayed on a spatial light modulator by performing additions of the zone plates, while the previous calculation method required performing the Fourier transform twice. The derivation and modeling of the zone plate are shown. In addition, the look-up table approach was introduced for further reduction in computation time. Experimental verification using a holographic display module based on the RR technique is presented.

Inequalities of Income and Inequalities of Longevity: A Cross-Country Study

PubMed Central

Plümper, Thomas

2016-01-01

Objectives. We examined the effects of market income inequality (income inequality before taxes and transfers) and income redistribution via taxes and transfers on inequality in longevity. Methods. We used life tables to compute Gini coefficients of longevity inequality for all individuals and for individuals who survived to at least 10 years of age. We regressed longevity inequality on market income inequality and income redistribution, and we controlled for potential confounders, in a cross-sectional time-series sample of up to 28 predominantly Western developed countries and up to 37 years (1974–2011). Results. Income inequality before taxes and transfers was positively associated with inequality in the number of years lived; income redistribution (the difference between market income inequality and income inequality after taxes and transfers were accounted for) was negatively associated with longevity inequality. Conclusions. To the extent that our estimated effects derived from observational data are causal, governments can reduce longevity inequality not only via public health policies, but also via their influence on market income inequality and the redistribution of incomes from the relatively rich to the relatively poor. PMID:26562120

A comparative analysis of early child health and development services and outcomes in countries with different redistributive policies

PubMed Central

2013-01-01

Background The social environment is a fundamental determinant of early child development and, in turn, early child development is a determinant of health, well-being, and learning skills across the life course. Redistributive policies aimed at reducing social inequalities, such as a welfare state and labour market policies, have shown a positive association with selected health indicators. In this study, we investigated the influence of redistributive policies specifically on the social environment of early child development in five countries with different political traditions. The objective of this analysis was to highlight similarities and differences in social and health services between the countries and their associations with other health outcomes that can inform better global early child development policies and improve early child health and development. Methods Four social determinants of early child development were selected to provide a cross-section of key time periods in a child’s life from prenatal to kindergarten. They included: 1) prenatal care, 2) maternal leave, 3) child health care, and 4) child care and early childhood education. We searched international databases and reports (e.g. Organization for Economic Cooperation and Development, World Bank, and UNICEF) to obtain information about early child development policies, services and outcomes. Results Although a comparative analysis cannot claim causation, our analysis suggests that redistributive policies aimed at reducing social inequalities are associated with a positive influence on the social determinants of early child development. Generous redistributive policies are associated with a higher maternal leave allowance and pay and more preventive child healthcare visits. A decreasing trend in infant mortality, low birth weight rate, and under five mortality rate were observed with an increase in redistributive policies. No clear influence of redistributive policies was observed on breastfeeding and immunization rates. In the analysis of child care and early education, the lack of uniform measures of early child development outcomes was apparent. Conclusions This paper provides further support for an association between redistributive policies and early child health and development outcomes, along with the organization of early child health and development services. PMID:24195544

A comparative analysis of early child health and development services and outcomes in countries with different redistributive policies.

PubMed

van den Heuvel, Meta; Hopkins, Jessica; Biscaro, Anne; Srikanthan, Cinntha; Feller, Andrea; Bremberg, Sven; Verkuijl, Nienke; Flapper, Boudien; Ford-Jones, Elizabeth Lee; Williams, Robin

2013-11-06

The social environment is a fundamental determinant of early child development and, in turn, early child development is a determinant of health, well-being, and learning skills across the life course. Redistributive policies aimed at reducing social inequalities, such as a welfare state and labour market policies, have shown a positive association with selected health indicators. In this study, we investigated the influence of redistributive policies specifically on the social environment of early child development in five countries with different political traditions. The objective of this analysis was to highlight similarities and differences in social and health services between the countries and their associations with other health outcomes that can inform better global early child development policies and improve early child health and development. Four social determinants of early child development were selected to provide a cross-section of key time periods in a child's life from prenatal to kindergarten. They included: 1) prenatal care, 2) maternal leave, 3) child health care, and 4) child care and early childhood education. We searched international databases and reports (e.g. Organization for Economic Cooperation and Development, World Bank, and UNICEF) to obtain information about early child development policies, services and outcomes. Although a comparative analysis cannot claim causation, our analysis suggests that redistributive policies aimed at reducing social inequalities are associated with a positive influence on the social determinants of early child development. Generous redistributive policies are associated with a higher maternal leave allowance and pay and more preventive child healthcare visits. A decreasing trend in infant mortality, low birth weight rate, and under five mortality rate were observed with an increase in redistributive policies. No clear influence of redistributive policies was observed on breastfeeding and immunization rates. In the analysis of child care and early education, the lack of uniform measures of early child development outcomes was apparent. This paper provides further support for an association between redistributive policies and early child health and development outcomes, along with the organization of early child health and development services.

Phase Curve Analysis of Super-Earth 55 Cancri e

NASA Astrophysics Data System (ADS)

Angelo, Isabel; Hu, Renyu

2018-01-01

One of the primary questions when characterizing Earth-sized and super-Earth-sized exoplanets is whether they have a substantial atmosphere like Earth and Venus, or a bare-rock surface that may come with a tenuous atmosphere like Mercury. Phase curves of the planets in thermal emission provide clues to this question, because a substantial atmosphere would transport heat more efficiently than a bare-rock surface. Analyzing phase curve photometric data around secondary eclipse has previously been used to study energy transport in the atmospheres of hot Jupiters. Here we use phase curve, Spitzer time-series photometry to study the thermal emission properties of the super-Earth exoplanet 55 Cancri e. We utilize a previously developed semi-analytical framework to fit a physical model to infrared photometric data of host star 55 Cancri from the Spitzer telescope IRAC 2 band at 4.5 μm. The model uses various parameters of planetary properties including Bond albedo, heat redistribution efficiency (i.e., the ratio between the radiative timescale and advective timescale of the photosphere), and atmospheric greenhouse factor. The phase curve of 55 Cancri e is dominated by thermal emission with an eastward-shifted hot spot located on the planet surface. We determine the heat redistribution efficiency to be ≈1.47, which implies that the advective timescale is on the same order as the radiative timescale. This requirement from the phase curve cannot be met by the bare-rock planet scenario, because heat transport by currents of molten lava would be too slow. The phase curve thus favors the scenario with a substantial atmosphere. Our constraints on the heat redistribution efficiency translate to a photosphere pressure of ~1.4 bar. The Spitzer IRAC 2 band is thus a window into the deep atmosphere of the planet 55 Cancri e.

A Case for an Atmosphere on Super-Earth 55 Cancri e

NASA Astrophysics Data System (ADS)

Angelo, Isabel; Hu, Renyu

2017-12-01

One of the primary questions when characterizing Earth-sized and super-Earth-sized exoplanets is whether they have a substantial atmosphere like Earth and Venus or a bare-rock surface like Mercury. Phase curves of the planets in thermal emission provide clues to this question, because a substantial atmosphere would transport heat more efficiently than a bare-rock surface. Analyzing phase-curve photometric data around secondary eclipses has previously been used to study energy transport in the atmospheres of hot Jupiters. Here we use phase curve, Spitzer time-series photometry to study the thermal emission properties of the super-Earth exoplanet 55 Cancri e. We utilize a semianalytical framework to fit a physical model to the infrared photometric data at 4.5 μm. The model uses parameters of planetary properties including Bond albedo, heat redistribution efficiency (I.e., ratio between radiative timescale and advective timescale of the atmosphere), and the atmospheric greenhouse factor. The phase curve of 55 Cancri e is dominated by thermal emission with an eastward-shifted hotspot. We determine the heat redistribution efficiency to be {1.47}-0.25+0.30, which implies that the advective timescale is on the same order as the radiative timescale. This requirement cannot be met by the bare-rock planet scenario because heat transport by currents of molten lava would be too slow. The phase curve thus favors the scenario with a substantial atmosphere. Our constraints on the heat redistribution efficiency translate to an atmospheric pressure of ˜1.4 bar. The Spitzer 4.5 μm band is thus a window into the deep atmosphere of the planet 55 Cancri e.

The effects of magmatic redistribution of heat producing elements on the lunar mantle evolution inferred from numerical models that start from various initial states

NASA Astrophysics Data System (ADS)

Ogawa, Masaki

2018-02-01

To discuss how redistribution of heat producing elements (HPEs) by magmatism affects the lunar mantle evolution depending on the initial condition, I present two-dimensional numerical models of magmatism in convecting mantle internally heated by incompatible HPEs. Mantle convection occurs beneath a stagnant lithosphere that inhibits recycling of the HPE-enriched crustal materials to the mantle. Magmatism is modeled by a permeable flow of magma generated by decompression melting through matrix. Migrating magma transports heat, mass, and HPEs. When the deep mantle is initially hot with the temperature TD around 1800 K at its base, magmatism starts from the beginning of the calculated history to extract HPEs from the mantle. The mantle is monotonously cooled, and magmatism ceases within 2 Gyr, accordingly. When the deep mantle is initially colder with TD around 1100 K, HPEs stay in the deep mantle for a longer time to let the planet be first heated up and then cooled only slightly. If, in addition, there is an HPE-enriched domain in the shallow mantle at the beginning of the calculation, magma continues ascending to the surface through the domain for more than 3 Gyr. The low TD models fit in with the thermal and magmatic history of the Moon inferred from spacecraft observations, although it is not clear if the models are consistent with the current understanding of the origin of the Moon and its magnetic field. Redistribution of HPEs by magmatism is a crucial factor that must be taken into account in future studies of the evolution of the Moon.

Auxin transport during root gravitropism: transporters and techniques.

PubMed

Geisler, M; Wang, B; Zhu, J

2014-01-01

Root gravitropism is a complex, plant-specific process allowing roots to grow downward into the soil. Polar auxin transport and redistribution are essential for root gravitropism. Here we summarise our current understanding of underlying molecular mechanisms and involved transporters that establish, maintain and redirect intercellular auxin gradients as the driving force for root gravitropism. We evaluate the genetic, biochemical and cell biological approaches presently used for the analysis of auxin redistribution and the quantification of auxin fluxes. Finally, we also discuss new tools that provide a higher spatial or temporal resolution and our technical needs for future gravitropism studies. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Landform Erosion and Volatile Redistribution on Ganymede and Callisto

NASA Technical Reports Server (NTRS)

Moore, Jeffrey Morgan; Howard, Alan D.; McKinnon, William B.; Schenk, Paul M.; Wood, Stephen E.

2009-01-01

We have been modeling landscape evolution on the Galilean satellites driven by volatile transport. Our work directly addresses some of the most fundamental issues pertinent to deciphering icy Galilean satellite geologic histories by employing techniques currently at the forefront of terrestrial, martian, and icy satellite landscape evolution studies [e.g., 1-6], including modeling of surface and subsurface energy and volatile exchanges, and computer simulation of long-term landform evolution by a variety of processes. A quantitative understanding of the expression and rates of landform erosion, and of volatile redistribution on landforms, is especially essential in interpreting endogenic landforms that have, in many cases, been significantly modified by erosion [e.g., 7-9].

Modeling aeolian transport in response to succession, disturbance and future climate: Dynamic long-term risk assessment for contaminant redistribution

USGS Publications Warehouse

Breshears, D.D.; Kirchner, T.B.; Whicker, J.J.; Field, J.P.; Allen, Craig D.

2012-01-01

Aeolian sediment transport is a fundamental process redistributing sediment, nutrients, and contaminants in dryland ecosystems. Over time frames of centuries or longer, horizontal sediment fluxes and associated rates of contaminant transport are likely to be influenced by succession, disturbances, and changes in climate, yet models of horizontal sediment transport that account for these fundamental factors are lacking, precluding in large part accurate assessment of human health risks associated with persistent soil-bound contaminants. We present a simple model based on empirical measurements of horizontal sediment transport (predominantly saltation) to predict potential contaminant transport rates for recently disturbed sites such as a landfill cover. Omnidirectional transport is estimated within vegetation that changes using a simple Markov model that simulates successional trajectory and considers three types of short-term disturbances (surface fire, crown fire, and drought-induced plant mortality) under current and projected climates. The model results highlight that movement of contaminated soil is sensitive to vegetation dynamics and increases substantially (e.g., > fivefold) when disturbance and/or future climate are considered. The time-dependent responses in horizontal sediment fluxes and associated contaminant fluxes were sensitive to variability in the timing of disturbance, with longer intervals between disturbance allowing woody plants to become dominant and crown fire and drought abruptly reducing woody plant cover. Our results, which have direct implications for contaminant transport and landfill management in the specific context of our assessment, also have general relevance because they highlight the need to more fully account for vegetation dynamics, disturbance, and changing climate in aeolian process studies.

Gauss-Seidel and Successive Overrelaxation Methods for Radiative Transfer with Partial Frequency Redistribution

NASA Astrophysics Data System (ADS)

Sampoorna, M.; Trujillo Bueno, J.

2010-04-01

The linearly polarized solar limb spectrum that is produced by scattering processes contains a wealth of information on the physical conditions and magnetic fields of the solar outer atmosphere, but the modeling of many of its strongest spectral lines requires solving an involved non-local thermodynamic equilibrium radiative transfer problem accounting for partial redistribution (PRD) effects. Fast radiative transfer methods for the numerical solution of PRD problems are also needed for a proper treatment of hydrogen lines when aiming at realistic time-dependent magnetohydrodynamic simulations of the solar chromosphere. Here we show how the two-level atom PRD problem with and without polarization can be solved accurately and efficiently via the application of highly convergent iterative schemes based on the Gauss-Seidel and successive overrelaxation (SOR) radiative transfer methods that had been previously developed for the complete redistribution case. Of particular interest is the Symmetric SOR method, which allows us to reach the fully converged solution with an order of magnitude of improvement in the total computational time with respect to the Jacobi-based local accelerated lambda iteration method.

Starch Biosynthesis in Developing Wheat Grain 1

PubMed Central

Keeling, Peter L.; Wood, John R.; Tyson, R. Huw; Bridges, Ian G.

1988-01-01

We have used 13C-labeled sugars and nuclear magnetic resonance (NMR) spectrometry to study the metabolic pathway of starch biosynthesis in developing wheat grain (Triticum aestivum cv Mardler). Our aim was to examine the extent of redistribution of 13C between carbons atoms 1 and 6 of [1-13C] or [6-13C]glucose (or fructose) incorporated into starch, and hence provide evidence for or against the involvement of triose phosphates in the metabolic pathway. Starch synthesis in the endosperm tissue was studied in two experimental systems. First, the 13C sugars were supplied to isolated endosperm tissue incubated in vitro, and second the 13C sugars were supplied in vivo to the intact plant. The 13C starch produced by the endosperm tissue of the grain was isolated and enzymically degraded to glucose using amyloglucosidase, and the distribution of 13C in all glucosyl carbons was quantified by 13C-NMR spectrometry. In all of the experiments, irrespective of the incubation time or incubation conditions, there was a similar pattern of partial (between 15 and 20%) redistribution of label between carbons 1 and 6 of glucose recovered from starch. There was no detectable increase over background 13C incidence in carbons 2 to 5. Within each experiment, the same pattern of partial redistribution of label was found in the glucosyl and fructosyl moieties of sucrose extracted from the tissue. Since it is unlikely that sucrose is present in the amyloplast, we suggest that the observed redistribution of label occurred in the cytosolic compartment of the endosperm cells and that both sucrose and starch are synthesized from a common pool of intermediates, such as hexose phosphate. We suggest that redistribution of label occurs via a cytosolic pathway cycle involving conversion of hexose phosphate to triose phosphate, interconversion of triose phosphate by triose phosphate isomerase, and resynthesis of hexose phosphate in the cytosol. A further round of triose phosphate interconversion in the amyloplast could not be detected. These data seriously weaken the argument for the selective uptake of triose phosphates by the amyloplast as part of the pathway of starch biosynthesis from sucrose in plant storage tissues. Instead, we suggest that a hexose phosphate such as glucose 1-phosphate, glucose 6-phosphate, or fructose 6-phosphate is the most likely candidate for entry into the amyloplast. A pathway of starch biosynthesis is presented, which is consistent with our data and with the current information on the intracellular distribution of enzymes in plant storage tissues. PMID:16666140

Ground-Water Availability in the Wailuku Area, Maui, Hawai'i

USGS Publications Warehouse

Gingerich, Stephen B.

2008-01-01

Most of the public water supply in Maui, Hawai'i, is from a freshwater lens in the Wailuku area of the island. Because of population growth, ground-water withdrawals from wells in this area increased from less than 10 Mgal/d during 1970 to about 23 Mgal/d during 2006. In response to increased withdrawals from the freshwater lens in the Wailuku area, water levels declined, the transition zone between freshwater and saltwater became shallower, and the chloride concentrations of water pumped from wells increased. These responses led to concern over the long-term sustainability of withdrawals from existing and proposed wells. A three-dimensional numerical ground-water flow and transport model was developed to simulate the effects of selected withdrawal and recharge scenarios on water levels, on the transition zone between freshwater and saltwater, and on surface-water/ground-water interactions. The model was constructed using time-varying recharge, withdrawals, and ocean levels. Hydraulic characteristics used to construct the model were initially based on published estimates but ultimately were varied to obtain better agreement between simulated and measured water levels and salinity profiles in the modeled area during the period 1926-2006. Scenarios included ground-water withdrawal at 2006 and 1996 rates and locations with average recharge (based on 2000-04 land use and 1926-2004 rainfall) and withdrawal at redistributed rates and locations with several different recharge scenarios. Simulation results indicate that continuing 1996 and 2006 withdrawal distributions into the future results in decreased water levels, a thinner freshwater lens, increased salinity from pumped wells, and higher salinity at several current withdrawal sites. A redistributed withdrawal condition in which ground-water withdrawal was redistributed to maximize withdrawal and minimize salinities in the withdrawn water was determined. The redistributed withdrawal simulates 27.1 Mgal/d of withdrawal from 14 wells or well fields in the Wailuku area. Simulation results from the five scenarios that include redistributed withdrawal conditions indicate the following for the Wailuku Aquifer Sector: (1) withdrawal during times of average recharge rates cause average water levels to decrease 2-3 ft and the transition zone to become more than 200 ft shallower after 150 years; (2) a 5-yr drought condition similar to the 1998-2002 drought results in additional salinity increases after 30 years (12.5 years of normal recharge after drought conditions) but only one well has salinity increases of concern; (3) additional recharge from restored streamflow significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems; and (4) a complete removal of irrigation recharge decreases water levels and increases salinity in the central isthmus where irrigation is reduced, but recharge through restored streams still significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems.

[Biodistribution and Postmortem Redistribution of Emamectin Benzoate in Intoxicated Mice].

PubMed

Tang, Wei-wei; Lin, Yu-cai; Lu, Yan-xu

2016-02-01

To investigate the lethal blood level, the target organs and tissues, the toxicant storage depots and the postmortem redistribution in mice died of emamectin benzoate poisoning. The mice model of emamectin benzoate poisoning was established via intragastric injection. The main poisoning symptoms and the clinical death times of mice were observed and recorded dynamically in the acute poisoning group as well as the sub-acute poisoning death group. The pathological and histomorphological changes of organs and tissues were observed after poisoning death. The biodistribution and postmortem redistribution of emamectin benzoate in the organs and tissues of mice were assayed by the enzyme-linked immunosorbent assay (ELISA) at 0h, 24h, 48h and 72h after death. The lethal blood concentrations and the concentrations of emamectin benzoate were detected by high performance liquid chromatography (HPLC) at different time points after death. The symptoms of nervous and respiratory system were observed within 15-30 min after intragastric injection. The average time of death was (45.8 ± 7.9) min in the acute poisoning group and (8.0 ± 1.4) d in the sub-acute poisoning group, respectively. The range of acute lethal blood level was 447.164 0-524.463 5 mg/L. The pathological changes of the organs and tissues were observed via light microscope and immunofluorescence microscope. The changes of emamectin benzoate content in the blood, heart, liver, spleen, lung, kidney and brain of poisoning mice showed regularity within 72 h after death (P < 0.05). The target organs of emamectin benzoate poisoning include heart, liver, kidney, lung, brain and contact position (stomach). The toxicant storage depots are kidney and liver. There is emamectin benzoate postmortem redistribution in mice.

Collective Thomson scattering measurements of fast-ion transport due to sawtooth crashes in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Rasmussen, J.; Nielsen, S. K.; Stejner, M.; Galdon-Quiroga, J.; Garcia-Munoz, M.; Geiger, B.; Jacobsen, A. S.; Jaulmes, F.; Korsholm, S. B.; Lazanyi, N.; Leipold, F.; Ryter, F.; Salewski, M.; Schubert, M.; Stober, J.; Wagner, D.; the ASDEX Upgrade Team; the EUROFusion MST1 Team

2016-11-01

Sawtooth instabilities can modify heating and current-drive profiles and potentially increase fast-ion losses. Understanding how sawteeth redistribute fast ions as a function of sawtooth parameters and of fast-ion energy and pitch is hence a subject of particular interest for future fusion devices. Here we present the first collective Thomson scattering (CTS) measurements of sawtooth-induced redistribution of fast ions at ASDEX Upgrade. These also represent the first localized fast-ion measurements on the high-field side of this device. The results indicate fast-ion losses in the phase-space measurement volume of about 50% across sawtooth crashes, in good agreement with values predicted with the Kadomtsev sawtooth model implemented in TRANSP and with the sawtooth model in the EBdyna_go code. In contrast to the case of sawteeth, we observe no fast-ion redistribution in the presence of fishbone modes. We highlight how CTS measurements can discriminate between different sawtooth models, in particular when aided by multi-diagnostic velocity-space tomography, and briefly discuss our results in light of existing measurements from other fast-ion diagnostics.

New Efforts of The Cergop Data-bank At Graz For Cergop-2

NASA Astrophysics Data System (ADS)

Pesec, P.; Stangl, G.

Starting with 1994 Graz/Austria took over the task of providing a data-bank for storing and re-distributing Rinex data measured at all CEGRN stations. In view of the future project CERGOP-2/Environment submitted to EU (5. FP)several modifications are required in order to take into account near real-time data dissemi- nation and to consider a near real-time publication of certified CERGOP-2 products for scientific and public access via Internet, and for political decision making in case of eventual hazard prediction. Due to the interdisciplinarity of environmental research the contents of different other data-banks should be included. We will present an approach which should result in a seamless data-bank updated in near real-time and placing at disposal methodology, data, results as well as current informations on the ongoing projects and future developments.

Evaluating the impact of WaterCell® Technology on pressure redistribution and comfort/discomfort of adults with limited mobility.

PubMed

Bartley, Carol; Stephens, Melanie

2017-05-01

The aim of the study was to evaluate the effect of WaterCell ® Technology on pressure redistribution and self-reported comfort and discomfort scores of adults with mobility problems who remain seated for extended periods of time. Twelve participants, were recruited and ranged in gender, age, height, weight, and body mass index. Five were male, seven were female, and five were permanent wheelchair users. Each participant was randomly allocated a chair, whose seat comprised of visco-elastic memory foam, high-elastic reflex foam, and watercells, to trial for a week. Data collected at day one and day seven included: interface pressure measurements taken across the gluteal region (peak and average); physiological observations of respiratory rate, pulse rate, and blood pressure; skin inspection and comfort and discomfort scores. Watercell ® technology was found to offer lower average pressures than those reported to cause potential skin injury. Peak pressure index findings were comparative to other studies. No correlation was found between discomfort intensity rating and pressure redistribution. Discomfort intensity rating was low for all participants and general discomfort ranged from very low to medium. Physiological observations decreased for 50% of participants over the seven days. From our study we have found that WaterCell ® technology offers comparable pressure redistribution for people with a disability who need to sit for prolonged periods of time and the chairs were found to be comfortable. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Exploring the potential for using 210Pbex measurements within a re-sampling approach to document recent changes in soil redistribution rates within a small catchment in southern Italy.

PubMed

Porto, Paolo; Walling, Desmond E; Cogliandro, Vanessa; Callegari, Giovanni

2016-11-01

In recent years, the fallout radionuclides caesium-137 ( 137 Cs) and unsupported lead-210 ( 210 Pb ex) have been successfully used to document rates of soil erosion in many areas of the world, as an alternative to conventional measurements. By virtue of their different half-lives, these two radionuclides are capable of providing information related to different time windows. 137 Cs measurements are commonly used to generate information on mean annual erosion rates over the past ca. 50-60 years, whereas 210 Pb ex measurements are able to provide information relating to a longer period of up to ca. 100 years. However, the time-integrated nature of the estimates of soil redistribution provided by 137 Cs and 210 Pb ex measurements can be seen as a limitation, particularly when viewed in the context of global change and interest in the response of soil redistribution rates to contemporary climate change and land use change. Re-sampling techniques used with these two fallout radionuclides potentially provide a basis for providing information on recent changes in soil redistribution rates. By virtue of the effectively continuous fallout input, of 210 Pb, the response of the 210 Pb ex inventory of a soil profile to changing soil redistribution rates and thus its potential for use with the re-sampling approach differs from that of 137 Cs. Its greater sensitivity to recent changes in soil redistribution rates suggests that 210 Pb ex may have advantages over 137 Cs for use in the re-sampling approach. The potential for using 210 Pb ex measurements in re-sampling studies is explored further in this contribution. Attention focuses on a small (1.38 ha) forested catchment in southern Italy. The catchment was originally sampled for 210 Pb ex measurements in 2001 and equivalent samples were collected from points very close to the original sampling points again in 2013. This made it possible to compare the estimates of mean annual erosion related to two different time windows. This comparison suggests that mean annual rates of net soil loss had increased during the period between the two sampling campaigns and that this increase was associated with a shift to an increased sediment delivery ratio. This change was consistent with independent information on likely changes in the sediment response of the study catchment provided by the available records of annual sediment yield and changes in the annual rainfall documented for the local area. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improvements on the accuracy of beam bugs

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

Chen, Y.J.; Fessenden, T.

1998-08-17

At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as ''beam bugs'', have been used throughoutmore » linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug.« less

Improvements on the accuracy of beam bugs

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

Chen, Y J; Fessenden, T

1998-09-02

At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as "beam bugs", have been used throughoutmore » linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug.« less

Anomalous transport in discrete arcs and simulation of double layers in a model auroral circuit

NASA Technical Reports Server (NTRS)

Smith, Robert A.

1987-01-01

The evolution and long-time stability of a double layer (DL) in a discrete auroral arc requires that the parallel current in the arc, which may be considered uniform at the source, be diverted within the arc to charge the flanks of the U-shaped double layer potential structure. A simple model is presented in which this current redistribution is effected by anomalous transport based on electrostatic lower hybrid waves driven by the flank structure itself. This process provides the limiting constraint on the double layer potential. The flank charging may be represented as that of a nonlinear transmission line. A simplified model circuit, in which the transmission line is represented by a nonlinear impedance in parallel with a variable resistor, is incorporated in a one-dimensional simulation model to give the current density at the DL boundaries. Results are presented for the scaling of the DL potential as a function of the width of the arc and the saturation efficiency of the lower hybrid instability mechanism.

Anomalous transport in discrete arcs and simulation of double layers in a model auroral circuit

NASA Technical Reports Server (NTRS)

Smith, Robert A.

1987-01-01

The evolution and long-time stability of a double layer in a discrete auroral arc requires that the parallel current in the arc, which may be considered uniform at the source, be diverted within the arc to charge the flanks of the U-shaped double-layer potential structure. A simple model is presented in which this current re-distribution is effected by anomalous transport based on electrostatic lower hybrid waves driven by the flank structure itself. This process provides the limiting constraint on the double-layer potential. The flank charging may be represented as that of a nonlinear transmission. A simplified model circuit, in which the transmission line is represented by a nonlinear impedance in parallel with a variable resistor, is incorporated in a 1-d simulation model to give the current density at the DL boundaries. Results are presented for the scaling of the DL potential as a function of the width of the arc and the saturation efficiency of the lower hybrid instability mechanism.

Portrait of an Aging Wheel

NASA Technical Reports Server (NTRS)

2004-01-01

This plot maps the increasing amounts of energy needed to spin Spirit's right front wheel drive, which has been showing signs of age. The wheel has now traveled six times farther than its design life. Since Spirit's 126th day on Mars, this wheel has required additional electric current to run at normal speeds, as indicated with blue diamonds on this graph. Efforts to improve the situation by redistributing the lubricant in the wheel with heat and rest were only mildly successful (pink squares). To cope with the condition, rover planners have come up with a creative solution: they will drive the rover backwards using five of six wheels. The sixth wheel will be activated only when the terrain demands it.

Modelling Deposition and Erosion rates with RadioNuclides (MODERN) - Part 2: A comparison of different models to convert 239+240Pu inventories into soil redistribution rates at unploughed sites.

PubMed

Arata, Laura; Alewell, Christine; Frenkel, Elena; A'Campo-Neuen, Annette; Iurian, Andra-Rada; Ketterer, Michael E; Mabit, Lionel; Meusburger, Katrin

2016-10-01

Sheet erosion is one of the major threats to alpine soils. To quantify its role and impact in the degradation processes of alpine grasslands, the application of Fallout Radionuclides (FRN) showed very promising results. The specific characteristics of plutonium 239 + 240 ( 239+240 Pu), such as the homogeneous fallout distribution, the long half-life and the cost and time effective measurements make this tracer application for investigating soil degradation in Alpine grasslands more suitable than any other FRN (e.g. 137 Cs). However, the conversion of 239+240 Pu inventories into soil erosion rates remains a challenge. Currently available conversion models have been developed mainly for 137 Cs with later adaptation to other FRN (e.g. Excess 210 Pb, and 7 Be), each model being defined for specific land use (ploughed and/or unploughed) and processes (erosion or deposition). As such, they may fail in describing correctly the distribution of Pu isotopes in the soil. A new conversion model, MODERN, with an adaptable algorithm to estimate erosion and deposition rates from any FRN inventory changes was recently proposed (Arata et al., 2016). In this complementary contribution, the authors compare the application of MODERN to other available conversion models. The results show a good agreement between soil redistribution rates obtained from MODERN and from the models currently used by the FRN scientific community (i.e. the Inventory Method). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Climate velocity and the future global redistribution of marine biodiversity

NASA Astrophysics Data System (ADS)

García Molinos, Jorge; Halpern, Benjamin S.; Schoeman, David S.; Brown, Christopher J.; Kiessling, Wolfgang; Moore, Pippa J.; Pandolfi, John M.; Poloczanska, Elvira S.; Richardson, Anthony J.; Burrows, Michael T.

2016-01-01

Anticipating the effect of climate change on biodiversity, in particular on changes in community composition, is crucial for adaptive ecosystem management but remains a critical knowledge gap. Here, we use climate velocity trajectories, together with information on thermal tolerances and habitat preferences, to project changes in global patterns of marine species richness and community composition under IPCC Representative Concentration Pathways (RCPs) 4.5 and 8.5. Our simple, intuitive approach emphasizes climate connectivity, and enables us to model over 12 times as many species as previous studies. We find that range expansions prevail over contractions for both RCPs up to 2100, producing a net local increase in richness globally, and temporal changes in composition, driven by the redistribution rather than the loss of diversity. Conversely, widespread invasions homogenize present-day communities across multiple regions. High extirpation rates are expected regionally (for example, Indo-Pacific), particularly under RCP8.5, leading to strong decreases in richness and the anticipated formation of no-analogue communities where invasions are common. The spatial congruence of these patterns with contemporary human impacts highlights potential areas of future conservation concern. These results strongly suggest that the millennial stability of current global marine diversity patterns, against which conservation plans are assessed, will change rapidly over the course of the century in response to ocean warming.

Charge Redistribution from Anomalous Magnetovorticity Coupling

DOE PAGES

Hattori, Koichi; Yin, Yi

2016-10-05

Here, we investigate novel transport phenomena in a chiral fluid originated from an interplay between a vorticity and strong magnetic field, which induces a redistribution of vector charges in the system and an axial current along the magnetic field. The corresponding transport coefficients are obtained from an energy-shift argument for the chiral fermions in the lowest Landau level due to a spin-vorticity coupling and also from diagrammatic computations on the basis of the linear response theory. Based on consistent results from both methods, we also observe that the transport coefficients are proportional to the anomaly coefficient and are independent ofmore » temperature and chemical potential. Finally, we speculate that these transport phenomena are connected to quantum anomaly.« less

Elliptic Relaxation of a Tensor Representation for the Redistribution Terms in a Reynolds Stress Turbulence Model

NASA Technical Reports Server (NTRS)

Carlson, J. R.; Gatski, T. B.

2002-01-01

A formulation to include the effects of wall proximity in a second-moment closure model that utilizes a tensor representation for the redistribution terms in the Reynolds stress equations is presented. The wall-proximity effects are modeled through an elliptic relaxation process of the tensor expansion coefficients that properly accounts for both correlation length and time scales as the wall is approached. Direct numerical simulation data and Reynolds stress solutions using a full differential approach are compared for the case of fully developed channel flow.

Invasive alien pests threaten the carbon stored in Europe's forests.

PubMed

Seidl, Rupert; Klonner, Günther; Rammer, Werner; Essl, Franz; Moreno, Adam; Neumann, Mathias; Dullinger, Stefan

2018-04-24

Forests mitigate climate change by sequestering large amounts of carbon (C). However, forest C storage is not permanent, and large pulses of tree mortality can thwart climate mitigation efforts. Forest pests are increasingly redistributed around the globe. Yet, the potential future impact of invasive alien pests on the forest C cycle remains uncertain. Here we show that large parts of Europe could be invaded by five detrimental alien pests already under current climate. Climate change increases the potential range of alien pests particularly in Northern and Eastern Europe. We estimate the live C at risk from a potential future invasion as 1027 Tg C (10% of the European total), with a C recovery time of 34 years. We show that the impact of introduced pests could be as severe as the current natural disturbance regime in Europe, calling for increased efforts to halt the introduction and spread of invasive alien species.

Extending the timescale for using beryllium 7 measurements to document soil redistribution by erosion

NASA Astrophysics Data System (ADS)

Walling, D. E.; Schuller, P.; Zhang, Y.; Iroumé, A.

2009-02-01

The need for spatially distributed information on soil mobilization, transfer, and deposition within the landscape by erosion has focused attention on the potential for using fallout radionuclides (i.e., 137Cs, excess 210Pb, and 7Be) to document soil redistribution rates. Whereas 137Cs and excess 210Pb are used to estimate medium- and longer-term erosion rates (i.e., approximately 45 years and 100 years, respectively), 7Be, by virtue of its short half-life (53 days), provides potential for estimating short-term soil redistribution on bare soils. However, the approach commonly used with this radionuclide means that it can only be applied to individual events or short periods of heavy rain. In addition, it is also frequently difficult to ensure that the requirement for spatially uniform 7Be inventories across the study area immediately prior to the study period is met. If the existing approach is applied to longer periods with several rainfall events (e.g., several weeks or more) soil redistribution is likely to be substantially underestimated. These problems limit the potential for using the 7Be approach, particularly in investigations where there is a need to assemble representative information on soil redistribution occurring during the entire wet season. This paper reports the development of a new or refined model for converting radionuclide measurements to estimates of soil redistribution (conversion model) for use with 7Be measurements, which permits much longer periods to be studied. This refined model aims to retain much of the simplicity of the existing approach, but takes account of the temporal distribution of both 7Be fallout and erosion during the study period and of the evolution of the 7Be depth distribution during this period. The approach was successfully tested using 7Be measurements from a study of short-term soil redistribution undertaken within an area of recently harvested forest located near Valdivia in Southern Chile. The study period extended over about 3 months and included the main part of the winter wet season of 2006. The estimates of soil redistribution obtained using the new conversion model were consistent with those obtained from erosion pins deployed within the same study area and were two to three times greater than those obtained using the approach and conversion model employed in existing studies.

Modelling of crater formation on anode surface by high-current vacuum arcs

NASA Astrophysics Data System (ADS)

Tian, Yunbo; Wang, Zhenxing; Jiang, Yanjun; Ma, Hui; Liu, Zhiyuan; Geng, Yingsan; Wang, Jianhua; Nordlund, Kai; Djurabekova, Flyura

2016-11-01

Anode melting and crater formation significantly affect interruption of high-current vacuum arcs. The primary objective of this paper is to theoretically investigate the mechanism of anode surface crater formation, caused by the combined effect of surface heating during the vacuum arc and pressure exerted on the molten surface by ions and electrons from the arc plasma. A model of fluid flow and heat transfer in the arc anode is developed and combined with a magnetohydrodynamics model of the vacuum arc plasma. Crater formation is observed in simulation for a peak arcing current higher than 15 kA on 40 mm diam. Cu electrodes spaced 10 mm apart. The flow of liquid metal starts after 4 or 5 ms of arcing, and the maximum velocities are 0.95 m/s and 1.39 m/s for 20 kA and 25 kA arcs, respectively. This flow redistributes thermal energy, and the maximum temperature of the anode surface does not remain in the center. Moreover, the condition for the liquid droplet formation on the anode surfaces is developed. The solidification process after current zero is also analyzed. The solidification time has been found to be more than 3 ms after 25 kA arcing. The long solidification time and sharp features on crater rims induce Taylor cone formation.

Mechanisms of Ocean Heat Uptake

NASA Astrophysics Data System (ADS)

Garuba, Oluwayemi

An important parameter for the climate response to increased greenhouse gases or other radiative forcing is the speed at which heat anomalies propagate downward in the ocean. Ocean heat uptake occurs through passive advection/diffusion of surface heat anomalies and through the redistribution of existing temperature gradients due to circulation changes. Atlantic meridional overturning circulation (AMOC) weakens in a warming climate and this should slow the downward heat advection (compared to a case in which the circulation is unchanged). However, weakening AMOC also causes a deep warming through the redistributive effect, thus increasing the downward rate of heat propagation compared to unchanging circulation. Total heat uptake depends on the combined effect of these two mechanisms. Passive tracers in a perturbed CO2 quadrupling experiments are used to investigate the effect of passive advection and redistribution of temperature anomalies. A new passive tracer formulation is used to separate ocean heat uptake into contributions due to redistribution and passive advection-diffusion of surface heating during an ocean model experiment with abrupt increase in surface temperature. The spatial pattern and mechanisms of each component are examined. With further experiments, the effects of surface wind, salinity and temperature changes in changing circulation and the resulting effect on redistribution in the individual basins are isolated. Analysis of the passive advection and propagation path of the tracer show that the Southern ocean dominates heat uptake, largely through vertical and horizontal diffusion. Vertical diffusion transports the tracer across isopycnals down to about 1000m in 100 years in the Southern ocean. Advection is more important in the subtropical cells and in the Atlantic high latitudes, both with a short time scale of about 20 years. The shallow subtropical cells transport the tracer down to about 500m along isopycnal surfaces, below this vertical diffusion takes over transport in the tropics; in the Atlantic, the MOC transports heat as deep 2000m in about 30 years. Redistributive surface heat uptake alters the total amount surface heat uptake among the basins. Compared to the passive-only heat uptake, which is about the same among the basins, redistribution nearly doubles the surface heat input into the Atlantic but makes smaller increases in the Indian and Pacific oceans for a net global increase of about 25%, in the perturbation experiment with winds unchanged. The passive and redistributive heat uptake components are further distributed among the basins through the global conveyor belt. The Pacific gains twice the surface heat input into it through lateral transport from the other two basins, as a result, the Atlantic and Pacific gain similar amounts of heat even though surface heat input is in the Atlantic is much bigger. Of this heat transport, most of the passive component comes from the Indian and the redistributive component comes from the Atlantic. Different surface forcing perturbation gives different circulation change pattern and as a result yield different redistributive uptake. Ocean heat uptake is more sensitive to wind forcing perturbation than to thermohaline forcing perturbation. About 2% reduction in subtropical cells transport and southern ocean transport, in the wind-change perturbation experiment, resulted in about 10% reduction in the global ocean heat uptake of wind-unchanged experiment. The AMOC weakened by about 35% and resulted in a 25% increase in passive heat uptake in the wind-unchanged experiment. Surface winds weakening reduces heat uptake by warming the reservoir surface temperatures, while MOC weakening increases heat input by a cooling reservoir surface temperatures. Thermohaline forcing perturbation is combination of salinity and temperature perturbations, both weaken the AMOC, however, they have opposite redistributive effects. Ocean surface freshening gives positive redistributive effect, while surface temperature increase gives negative redistributive effect on heat uptake. The salinity effect dominates the redistributive effect for thermohaline perturbation.

Robust random telegraph conductivity noise in single crystals of the ferromagnetic insulating manganite La0.86Ca0.14MnO3

NASA Astrophysics Data System (ADS)

Przybytek, J.; Fink-Finowicki, J.; Puźniak, R.; Shames, A.; Markovich, V.; Mogilyansky, D.; Jung, G.

2017-03-01

Robust random telegraph conductivity fluctuations have been observed in La0.86Ca0.14MnO3 manganite single crystals. At room temperatures, the spectra of conductivity fluctuations are featureless and follow a 1 /f shape in the entire experimental frequency and bias range. Upon lowering the temperature, clear Lorentzian bias-dependent excess noise appears on the 1 /f background and eventually dominates the spectral behavior. In the time domain, fully developed Lorentzian noise appears as pronounced two-level random telegraph noise with a thermally activated switching rate, which does not depend on bias current and applied magnetic field. The telegraph noise is very robust and persists in the exceptionally wide temperature range of more than 50 K. The amplitude of the telegraph noise decreases exponentially with increasing bias current in exactly the same manner as the sample resistance increases with the current, pointing out the dynamic current redistribution between percolation paths dominated by phase-separated clusters with different conductivity as a possible origin of two-level conductivity fluctuations.

Adapting radiotherapy to hypoxic tumours

NASA Astrophysics Data System (ADS)

Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

2006-10-01

In the current work, the concepts of biologically adapted radiotherapy of hypoxic tumours in a framework encompassing functional tumour imaging, tumour control predictions, inverse treatment planning and intensity modulated radiotherapy (IMRT) were presented. Dynamic contrast enhanced magnetic resonance imaging (DCEMRI) of a spontaneous sarcoma in the nasal region of a dog was employed. The tracer concentration in the tumour was assumed related to the oxygen tension and compared to Eppendorf histograph measurements. Based on the pO2-related images derived from the MR analysis, the tumour was divided into four compartments by a segmentation procedure. DICOM structure sets for IMRT planning could be derived thereof. In order to display the possible advantages of non-uniform tumour doses, dose redistribution among the four tumour compartments was introduced. The dose redistribution was constrained by keeping the average dose to the tumour equal to a conventional target dose. The compartmental doses yielding optimum tumour control probability (TCP) were used as input in an inverse planning system, where the planning basis was the pO2-related tumour images from the MR analysis. Uniform (conventional) and non-uniform IMRT plans were scored both physically and biologically. The consequences of random and systematic errors in the compartmental images were evaluated. The normalized frequency distributions of the tracer concentration and the pO2 Eppendorf measurements were not significantly different. 28% of the tumour had, according to the MR analysis, pO2 values of less than 5 mm Hg. The optimum TCP following a non-uniform dose prescription was about four times higher than that following a uniform dose prescription. The non-uniform IMRT dose distribution resulting from the inverse planning gave a three times higher TCP than that of the uniform distribution. The TCP and the dose-based plan quality depended on IMRT parameters defined in the inverse planning procedure (fields and step-and-shoot intensity levels). Simulated random and systematic errors in the pO2-related images reduced the TCP for the non-uniform dose prescription. In conclusion, improved tumour control of hypoxic tumours by dose redistribution may be expected following hypoxia imaging, tumour control predictions, inverse treatment planning and IMRT.

Array distribution in data-parallel programs

NASA Technical Reports Server (NTRS)

Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert; Sheffler, Thomas J.

1994-01-01

We consider distribution at compile time of the array data in a distributed-memory implementation of a data-parallel program written in a language like Fortran 90. We allow dynamic redistribution of data and define a heuristic algorithmic framework that chooses distribution parameters to minimize an estimate of program completion time. We represent the program as an alignment-distribution graph. We propose a divide-and-conquer algorithm for distribution that initially assigns a common distribution to each node of the graph and successively refines this assignment, taking computation, realignment, and redistribution costs into account. We explain how to estimate the effect of distribution on computation cost and how to choose a candidate set of distributions. We present the results of an implementation of our algorithms on several test problems.

Exciton Seebeck effect in molecular systems

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

Yan, Yun-An, E-mail: yunan@nano.gznc.edu.cn; Cai, Shaohong

2014-08-07

We investigate the exciton dynamics under temperature difference with the hierarchical equations of motion. Through a nonperturbative simulation of the transient absorption of a heterogeneous trimer model, we show that the temperature difference causes exciton population redistribution and affects the exciton transfer time. It is found that one can reproduce not only the exciton population redistribution but also the change of the exciton transfer time induced by the temperature difference with a proper tuning of the site energies of the aggregate. In this sense, there exists a site energy shift equivalence for any temperature difference in a broad range. Thismore » phenomenon is similar to the Seebeck effect as well as spin Seebeck effect and can be named as exciton Seebeck effect.« less

Evolution of the lithium morphology from cycling of thin film solid state batteries

DOE PAGES

Dudney, Nancy J.

2017-03-11

Thin film batteries with a Lipon electrolyte and Li metal anode can be cycled thousands of times. During this time there is a gradual redistribution of the lithium at the top surface; the morphology that develops depends on a number of factors but is largely driven by dewetting. In this work, this redistribution is characterized as functions of the cycle number, duty cycle, cathode composition, and protective coating over the lithium. Observations of wrinkled and pitted surfaces are discussed considering the effects of defects and diffusion in the lithium and influences of film stresses and surface energy. In conclusion, similarmore » processes may impact solid state lithium batteries with higher energy per active area.« less

Evolution of the lithium morphology from cycling of thin film solid state batteries

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

Dudney, Nancy J.

Thin film batteries with a Lipon electrolyte and Li metal anode can be cycled thousands of times. During this time there is a gradual redistribution of the lithium at the top surface; the morphology that develops depends on a number of factors but is largely driven by dewetting. In this work, this redistribution is characterized as functions of the cycle number, duty cycle, cathode composition, and protective coating over the lithium. Observations of wrinkled and pitted surfaces are discussed considering the effects of defects and diffusion in the lithium and influences of film stresses and surface energy. In conclusion, similarmore » processes may impact solid state lithium batteries with higher energy per active area.« less

Preferential Redistribution of Fine-Grained Particles in the Panama Basin and Potential Errors in 230Th-Derived Focusing Factors

NASA Astrophysics Data System (ADS)

Marcantonio, F.; Lyle, M. W.; Ibrahim, R.

2013-12-01

The 230Th constant-flux proxy technique, commonly used in paleoceanography to estimate sediment fluxes, is thought to differentiate lateral from vertical fluxes of sediment at sites that have undergone sediment redistribution. However, redistribution processes (focusing or winnowing) are expected to fractionate fine particles from those that are coarse. Since fine particles with greater surface area are known to contain greater concentrations of 230Th, one might expect that sediment redistribution would bias 230Th-derived sediment mass accumulation rates (MARs). We investigate this possibility in two regions of the Panama Basin where significant sediment focusing has been hypothesized to occur. We examine multicore sediments from paired sites at two locations, one close to the equator at the southern limit of the Panama Basin (Carnegie Ridge) where upwelling and primary productivity are high, and one at 6°N at the northern boundary of the Panama Basin (Cocos Ridge), where primary productivity is lower. The multicores, which are constrained by radiocarbon ages that span the latest Holocene at each paired site, represent regions that have undergone potential winnowing and focusing (thin vs thick sediment drapes identified using seismic reflection) at each Panama Basin location. Since the distance separating the paired sites at each location is no more than about 50 km, one would expect the 230Th-derived MARs to be similar, i.e., the rain rate should not be significantly different at each of the paired sites. The radiocarbon-derived sand fraction (>63-μm) MARs, which likely represent the vertical rain of particles not transported by bottom currents, are identical at each of the paired sites, with fluxes at the Carnegie Ridge about 3.5 times greater than those at the Cocos Ridge over the past several thousand years. Over the same time period, the 230Th-normalized MARs are relatively similar at both the Carnegie and Cocos sites, but are different by about 60% at each of the paired sites, with the higher MARs always at the potentially winnowed sites. The 'thick' Carnegie Ridge site has a 230Th-derived focusing factor of about 6. However, we believe that, given our observations of the radiocarbon-derived fluxes of sand, the high 230Th-derived focusing factor is likely an overestimate of the degree of focusing, and the average 230Th-derived MAR is likely an underestimate of the true MAR. Similarly, the biasing for the 'thin' Cocos site that has a 230Th-derived focusing factor of 0.2 (i.e., potential winnowing) is expected to be the opposite, namely, 230Th-derived fluxes are likely being overestimated there. The quantitative extent to which 230Th-derived focusing factors have been over- and under-estimated in the Panama Basin will be discussed. We hypothesize that size fractionation, as well as 230Th focusing errors, occur most frequently at lower current velocities where the fine and coarse fraction of the sediment components are more effectively sorted from each other.

Time scales and mechanisms of estuarine variability, a synthesis from studies of San Francisco Bay

USGS Publications Warehouse

Cloern, J.E.; Nichols, F.H.

1985-01-01

This review of the preceding papers suggests that temporal variability in San Francisco Bay can be characterized by four time scales (hours, days-weeks, months, years) and associated with at least four mechanisms (variations in freshwater inflow, tides, wind, and exchange with coastal waters). The best understood component of temporal variability is the annual cycle, which is most obviously influenced by seasonal variations in freshwater inflow. The winter season of high river discharge is characterized by: large-scale redistribution of the salinity field (e.g. the upper estuary becomes a riverine system); enhanced density stratification and gravitational circulation with shortened residence times in the bay; decreased tissue concentrations of some contaminants (e.g. copper) in resident bivalves; increased estuarine inputs of river-borne materials such as dissolved inorganic nutrients (N, P, Si), suspended sediments, and humic materials; radical redistributions of pelagic organisms such as copepods and fish; low phutoplankton biomass and primary productivity in the upper estuary; and elimination of freshwater-intolerant species of macroalgae and benthic infauna from the upper estuary. Other mechanisms modulate this river-driven annual cycle: (1) wind speed is highly seasonal (strongest in summer) and causes seasonal variations in atmosphere-water column exchange of dissolved gases, resuspension, and the texture of surficial sediments; (2) seasonal variations in the coastal ocean (e.g. the spring-summer upwelling season) influence species composition of plankton and nutrient concentrations that are advected into the bay; and (3) the annual temperature cycle influences a few selected features (e.g. production and hatching of copepod resting eggs). Much of the interannual variability in San Francisco Bay is also correlated with freshwater inflow: wet years with persistently high river discharge are characterized by persistent winter-type conditions. Mechanisms of short-term variability are not as well understood, although some responses to storm events (pulses in residual currents from wind forcing, erosion of surficial sediments by wind waves, redistribution of fish populations) and the neap-spring tidal cycle (enhanced salinity stratification, gravitational circulation, and phytoplankton biomass during neap tides) have been quantified. In addition to these somewhat predictable features of variability are (1) largely unexplained episodic events (e.g. anomalous blooms of drift macroalgae), and (2) long-term trends directly attributable to human activities (e.g. introduction of exotic species that become permanent members of the biota). ?? 1985 Dr W. Junk Publishers.

Temperature dependent of IVR investigated by steady-state and time-frequency resolved CARS for liquid nitrobenzene and nitromethane

NASA Astrophysics Data System (ADS)

Yang, Yanqiang; Zhu, Gangbei; Yan, Lin; Liu, Xiaosong; Yang's Ultrafast Spectroscopy Group Team

2017-06-01

Intramolecular vibrational energy redistribution (IVR) is important process in thermal decomposition, shock chemistry and photochemistry. Anti-Stokes Raman scattering is sensitive to the vibrational population in excited states because only vibrational excited states are responsible to the anti-Stokes Raman scattering, does not vibrational ground states. In this report, steady-state anti-Stokes Raman spectroscopy and broad band ultrafast coherent anti-Stokes Raman scattering (CARS) are performed. The steady-state anti-Stokes Raman spectroscopy shows temperature dependent of vibrational energy redistribution in vibrational excited-state molecule, and reveal that, in liquid nitrobenzene, with temperature increasing, vibrational energy is mainly redistributed in NO2 symmetric stretching mode, and phenyl ring stretching mode of νCC. For liquid nitromethane, it is found that, with temperature increasing, vibrational energy concentrate in CN stretching mode and methyl umbrella vibrational mode. In the broad band ultrafast CARS experiment, multiple vibrational modes are coherently excited to vibrational excited states, and the time-frequency resolved CARS spectra show the coincident IVR processes. This work is supported by the National Natural Science Foundation of China (Grant Numbers 21673211 and 11372053), and the Science Challenging Program (Grant Number JCKY2016212A501).

Calpain mediates AIF-regulated caspase-independent pathway in cisplatin-induced apoptosis

NASA Astrophysics Data System (ADS)

Liu, Lei; Xing, Da; Chen, Wei R.

2007-11-01

Mitochondrial apoptosis inducing factor (AIF) on activation can translocate to the nucleus and induce cell death via caspase-independent pathway in cisplatin-induced apoptosis. Yet the precise signal transduction pathway(s) which regulates AIF-induced apoptotic pathway still remains poorly understood. In this study, we investigated the molecular mechanism of AIF release and redistribution in cisplatin-induced apoptosis in living ASTC-a-1 cells, as assessed by real-time anlysis. Herein, We report that during cisplatin-induced apoptosis, calpain activation, as measured in intact cells by a fluorescent substrates, is an early event, taking place well before AIF release and caspase-3 activation. Confocal imaging of the cells transfected with AIF-GFP demonstrated that AIF release occurred about 9 h after cisplatin treatment. The event proceeded progressively over time, coinciding with a nuclear translocation and lasting for more than 2 hours. AIF release and redistribution were effectively inhibited in samples co-treated with calpeptin and PD150606, two selective calpain inhibitors. Therefore, our results clearly show the kinetics of AIF release and redistribution in cisplatin-induced apoptosis in living ASTC-a-1 cells, and calpain played a crucial role in these events.

Indigenous Higher Education in Mexico and Brazil: Between Redistribution and Recognition

ERIC Educational Resources Information Center

Oyarzún, Juan de Dios; Perales Franco, Cristina; McCowan, Tristan

2017-01-01

Indigenous groups in Latin America face a double exclusion from higher education, with low levels of access to institutions and little acknowledgement of their distinctive cultural and epistemological traditions within the curriculum. This article assesses current policies in Mexico and Brazil towards indigenous populations in higher education,…

Weed biocontrol in the EU: from serendipity to strategy

USDA-ARS?s Scientific Manuscript database

Biological control of weeds is a globally-recognized approach to the management of the worst invasive plants in the world. Unfortunately, accidental introduction of agents account for most weed biocontrol in the EU, but do include a number of current or emerging successes. From the redistribution of...

Global Confinement, Sawtooth Mixing, and Stochastic Diffusion Ripple Loss of Fast ICRF-driven H+ Minority Ions in TFTR

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

Petrov, M.P.; Bell, R.; Budny, R.V.

1998-07-01

This paper presents studies of ICRF-driven H+ minority ions in TFTR (Tokamak Fusion Test Reator) deuterium plasmas using primarily passive Ho flux detection in the energy range of 0.2-1.0 MeV with some corroborating active (lithium pellet charge exchange) measurements. It is shown that in the passive mode the main donors for the neutralization of H+ ions in this energy range are C5+ ions. The measured effective H+ tail temperatures range from 0.15 MeV at an ICRF power of 2 MW to 0.35 MeV at 6 MW. Analysis of the ICRF-driven H+ ion energy balance has been performed on the basismore » of the dependence of effective H+ temperatures on the plasma parameters. The analysis showed that H+ confinement times are comparable with their slowing-down times and tended to decrease with increasing ICRF power. Radial redistribution of ICRF-driven H+ ions was detected when giant sawtooth crashes occurred during the ICRF heating. The redistribution affected ions with energy below 0.7-0.8 MeV. The sawtooth crashes displace H+ ions outward along the plasma major radius into the stochastic ripple diffusion domain were those ions are lost in about 10 milliseconds. These observations are consistent with the model of the redistribution of energetic particles developed previously to explain the results of deuterium-tritium alpha-particle redistribution due to sawteeth observed in TFTR. The experimental data are also consistent with ORBIT code simulations of H+ stochastic ripple diffusion losses.« less

47 CFR 73.9001 - Redistribution control of digital television broadcasts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Redistribution control of digital television... RADIO SERVICES RADIO BROADCAST SERVICES Digital Broadcast Television Redistribution Control § 73.9001 Redistribution control of digital television broadcasts. Licensees of TV broadcast stations may utilize the...

A distributed real-time model of degradation in a solid oxide fuel cell, part I: Model characterization

NASA Astrophysics Data System (ADS)

Zaccaria, V.; Tucker, D.; Traverso, A.

2016-04-01

Despite the high efficiency and flexibility of fuel cells, which make them an attractive technology for the future energy generation, their economic competitiveness is still penalized by their short lifetime, due to multiple degradation phenomena. As a matter of fact, electrochemical performance of solid oxide fuel cells (SOFCs) is reduced because of different degradation mechanisms, which depend on operating conditions, fuel and air contaminants, impurities in materials, and others. In this work, a real-time, one dimensional (1D) model of a SOFC is used to simulate the effects of voltage degradation in the cell. Different mechanisms are summarized in a simple empirical expression that relates degradation rate to cell operating parameters (current density, fuel utilization and temperature), on a localized basis. Profile distributions of different variables during cell degradation are analyzed. In particular, the effect of degradation on current density, temperature, and total resistance of the cell are investigated. An analysis of localized degradation effects shows how different parts of the cell degrade at a different time rate, and how the various profiles are redistributed along the cell as consequence of different degradation rates.

The electromagnetic environment in CFC structures

NASA Technical Reports Server (NTRS)

Hardwick, C. J.; Haigh, S. J.

1991-01-01

Extensive measurements of induced voltages and currents were made using a CFC (carbon fiber composites) horizontal stabilizer from the A320 as a test bed. The work was done to investigate the efficacy of various protection schemes to reduce the magnitudes of the induced voltages and validate a computer program INDCAL. Results indicate that a good understanding of the various induced voltage mechanisms including the long wave effect due to current redistribution was obtained.

Nano- and micro-scale Bi-substituted iron garnet films for photonics and magneto-optic eddy current defectoscopy

NASA Astrophysics Data System (ADS)

Berzhansky, V. N.; Karavainikov, A. V.; Mikhailova, T. V.; Prokopov, A. R.; Shaposhnikov, A. N.; Shumilov, A. G.; Lugovskoy, N. V.; Semuk, E. Yu.; Kharchenko, M. F.; Lukienko, I. M.; Kharchenko, Yu. M.; Belotelov, V. I.

2017-10-01

Synthesis technology of nano-scale Bi-substituted iron garnets films with high magneto-optic activity for photonics and plasmonics applications were proposed. The micro-scale single-crystal garnet films with different types of magnetic anisotropy as a magneto-optic sensors were synthesized. It was shown that easy-axis anisotropy films demonstrated the best results for visualization of redistribution eddy current magnetic field near defects.

Sediment Redistribution and Seabed Modification in the Western Adriatic

DTIC Science & Technology

2003-09-30

are slated for use in the model. These changes to the input files result in both better resolution of the Western Adriatic Coastal Current ( WACC ...by transport within the WACC during strong Bora winds (figure 2). Figure 2: Salinity and currents driven by wind stress and buoyancy output...from the northeast, termed “Bora” winds, which intensify the WACC and create merges the 4 discharge of individual Apennine Rivers into a line

13 CFR 309.2 - Redistributions under part 307.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Redistributions under part 307. 309.2 Section 309.2 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE REDISTRIBUTIONS OF INVESTMENT ASSISTANCE § 309.2 Redistributions under part 307. (a) A Recipient...

13 CFR 309.1 - Redistributions under parts 303, 305 and 306.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Redistributions under parts 303, 305 and 306. 309.1 Section 309.1 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE REDISTRIBUTIONS OF INVESTMENT ASSISTANCE § 309.1 Redistributions under parts 303, 305...

Outcomes and disparities in liver transplantation will be improved by redistricting-cons.

PubMed

Goldberg, David Seth; Karp, Seth

2017-04-01

Over the last 2 years, the liver transplant community has been debating a proposal to redraw the maps of organ distribution. The basis for these proposed changes is reported disparities in severity of illness at transplantation across the USA - however, this is based on the allocation model for end-stage liver disease score. In this review, we provide a critical overview of the redistribution proposal, its flaws and how it may worsen outcomes and exacerbate disparities in liver transplantation. The main findings we highlight are data questioning the disparity metric used to justify the redistribution. We also review data published in recent articles and presented at public forums questioning whether there truly are disparities in access to transplant care among the broader population with liver disease, and whether disparities even getting to the waitlist are important and not to be ignored. This review article highlights major methodological and policy flaws with the current redistribution proposal. We demonstrate how the waitlist disparities that the proposal is intended to fix are not as they seem. Furthermore, if this proposal is passed, outcomes of liver transplantation nationally may worsen, and disparities for those with limited access to healthcare will worsen.

The role of stellar radial motions in shaping galaxy surface brightness profiles

NASA Astrophysics Data System (ADS)

Ruiz-Lara, T.; Few, C. G.; Florido, E.; Gibson, B. K.; Pérez, I.; Sánchez-Blázquez, P.

2017-12-01

Aims: The physics driving features such as breaks observed in galaxy surface brightness (SB) profiles remains contentious. Here, we assess the importance of stellar radial motions in shaping their characteristics. Methods: We use the simulated Milky Way-mass cosmological discs from the Ramses Disc Environment Study (RaDES) to characterise the radial redistribution of stars in galaxies displaying type-I (pure exponentials), II (downbending), and III (upbending) SB profiles. We compare radial profiles of the mass fractions and the velocity dispersions of different sub-populations of stars according to their birth and current location. Results: Radial redistribution of stars is important in all galaxies regardless of their light profiles. Type-II breaks seem to be a consequence of the combined effects of outward-moving and accreted stars. The former produce shallower inner profiles (lack of stars in the inner disc) and accumulate material around the break radius and beyond, strengthening the break; the latter can weaken or even convert the break into a pure exponential. Further accretion from satellites can concentrate material in the outermost parts, leading to type-III breaks that can coexist with type-II breaks, but situated further out. Type-III galaxies would be the result of an important radial redistribution of material throughout the entire disc, as well as a concentration of accreted material in the outskirts. In addition, type-III galaxies display the most efficient radial redistribution and the largest number of accreted stars, followed by type-I and II systems, suggesting that type-I galaxies may be an intermediate case between types II and III. In general, the velocity dispersion profiles of all galaxies tend to flatten or even increase around the locations where the breaks are found. The age and metallicity profiles are also affected, exhibiting different inner gradients depending on their SB profile, being steeper in the case of type-II systems (as found observationally). The steep type-II profiles might be inherent to their formation rather than acquired via radial redistribution.

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

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

Qi, Y.; Liu, S.; Lindenberg, A. M.

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈ 10 11 K/s) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO 3 occurring on few picosecond time scales. Here, we explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on amore » ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO 3 and BaTiO 3. Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.« less

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

DOE PAGES

Qi, Y.; Liu, S.; Lindenberg, A. M.; ...

2018-01-30

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈ 10 11 K/s) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO 3 occurring on few picosecond time scales. Here, we explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on amore » ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO 3 and BaTiO 3. Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.« less

Ultrafast Electric Field Pulse Control of Giant Temperature Change in Ferroelectrics

NASA Astrophysics Data System (ADS)

Qi, Y.; Liu, S.; Lindenberg, A. M.; Rappe, A. M.

2018-01-01

There is a surge of interest in developing environmentally friendly solid-state-based cooling technology. Here, we point out that a fast cooling rate (≈1011 K /s ) can be achieved by driving solid crystals to a high-temperature phase with a properly designed electric field pulse. Specifically, we predict that an ultrafast electric field pulse can cause a giant temperature decrease up to 32 K in PbTiO3 occurring on few picosecond time scales. We explain the underlying physics of this giant electric field pulse-induced temperature change with the concept of internal energy redistribution: the electric field does work on a ferroelectric crystal and redistributes its internal energy, and the way the kinetic energy is redistributed determines the temperature change and strongly depends on the electric field temporal profile. This concept is supported by our all-atom molecular dynamics simulations of PbTiO3 and BaTiO3 . Moreover, this internal energy redistribution concept can also be applied to understand electrocaloric effect. We further propose new strategies for inducing giant cooling effect with ultrafast electric field pulse. This Letter offers a general framework to understand electric-field-induced temperature change and highlights the opportunities of electric field engineering for controlled design of fast and efficient cooling technology.

Automatic generation of efficient array redistribution routines for distributed memory multicomputers

NASA Technical Reports Server (NTRS)

Ramaswamy, Shankar; Banerjee, Prithviraj

1994-01-01

Appropriate data distribution has been found to be critical for obtaining good performance on Distributed Memory Multicomputers like the CM-5, Intel Paragon and IBM SP-1. It has also been found that some programs need to change their distributions during execution for better performance (redistribution). This work focuses on automatically generating efficient routines for redistribution. We present a new mathematical representation for regular distributions called PITFALLS and then discuss algorithms for redistribution based on this representation. One of the significant contributions of this work is being able to handle arbitrary source and target processor sets while performing redistribution. Another important contribution is the ability to handle an arbitrary number of dimensions for the array involved in the redistribution in a scalable manner. Our implementation of these techniques is based on an MPI-like communication library. The results presented show the low overheads for our redistribution algorithm as compared to naive runtime methods.

The redistributive effect of health care finance in twelve OECD countries.

PubMed

van Doorslaer, E; Wagstaff, A; van der Burg, H; Christiansen, T; Citoni, G; Di Biase, R; Gerdtham, U G; Gerfin, M; Gross, L; Häkinnen, U; John, J; Johnson, P; Klavus, J; Lachaud, C; Lauritsen, J; Leu, R; Nolan, B; Pereira, J; Propper, C; Puffer, F; Rochaix, L; Schellhorn, M; Sundberg, G; Winkelhake, O

1999-06-01

The OECD countries finance their health care through a mixture of taxes, social insurance contributions, private insurance premiums and out-of-pocket payments. The various payment sources have very different implications for both vertical and horizontal equity and on redistributive effect which is a function of both. This paper presents results on the income redistribution consequences of the health care financing mixes adopted in twelve OECD countries by decomposing the overall income redistributive effect into a progressivity, horizontal inequity and reranking component. The general finding of this study is that the vertical effect is much more important than horizontal inequity and reranking in determining the overall redistributive effect but that their relative importance varies by source of payment. Public finance sources tend to have small positive redistributive effects and less differential treatment while private financing sources generally have (larger) negative redistributive effects which are to a substantial degree caused by differential treatment.

Frequency, thermal and voltage supercapacitor characterization and modeling

NASA Astrophysics Data System (ADS)

Rafik, F.; Gualous, H.; Gallay, R.; Crausaz, A.; Berthon, A.

A simple electrical model has been established to describe supercapacitor behaviour as a function of frequency, voltage and temperature for hybrid vehicle applications. The electrical model consists of 14 RLC elements, which have been determined from experimental data using electrochemical impedance spectroscopy (EIS) applied on a commercial supercapacitor. The frequency analysis has been extended for the first time to the millihertz range to take into account the leakage current and the charge redistribution on the electrode. Simulation and experimental results of supercapacitor charge and discharge have been compared and analysed. A good correlation between the model and the EIS results has been demonstrated from 1 mHz to 1 kHz, from -20 to 60 °C and from 0 to 2.5 V.

Time-resolved rhodopsin activation currents in a unicellular expression system.

PubMed Central

Sullivan, J M; Shukla, P

1999-01-01

The early receptor current (ERC) is the charge redistribution occurring in plasma membrane rhodopsin during light activation of photoreceptors. Both the molecular mechanism of the ERC and its relationship to rhodopsin conformational activation are unknown. To investigate whether the ERC could be a time-resolved assay of rhodopsin structure-function relationships, the distinct sensitivity of modern electrophysiological tools was employed to test for flash-activated ERC signals in cells stably expressing normal human rod opsin after regeneration with 11-cis-retinal. ERCs are similar in waveform and kinetics to those found in photoreceptors. The action spectrum of the major R(2) charge motion is consistent with a rhodopsin photopigment. The R(1) phase is not kinetically resolvable and the R(2) phase, which overlaps metarhodopsin-II formation, has a rapid risetime and complex multiexponential decay. These experiments demonstrate, for the first time, kinetically resolved electrical state transitions during activation of expressed visual pigment in a unicellular environment (single or fused giant cells) containing only 6 x 10(6)-8 x 10(7) molecules of rhodopsin. This method improves measurement sensitivity 7 to 8 orders of magnitude compared to other time-resolved techniques applied to rhodopsin to study the role particular amino acids play in conformational activation and the forces that govern those transitions. PMID:10465746

Ill-defined causes of death in Brazil: a redistribution method based on the investigation of such causes

PubMed Central

França, Elisabeth; Teixeira, Renato; Ishitani, Lenice; Duncan, Bruce Bartholow; Cortez-Escalante, Juan José; de Morais, Otaliba Libânio; Szwarcwald, Célia Landman

2014-01-01

OBJECTIVE To propose a method of redistributing ill-defined causes of death (IDCD) based on the investigation of such causes. METHODS In 2010, an evaluation of the results of investigating the causes of death classified as IDCD in accordance with chapter 18 of the International Classification of Diseases (ICD-10) by the Mortality Information System was performed. The redistribution coefficients were calculated according to the proportional distribution of ill-defined causes reclassified after investigation in any chapter of the ICD-10, except for chapter 18, and used to redistribute the ill-defined causes not investigated and remaining by sex and age. The IDCD redistribution coefficient was compared with two usual methods of redistribution: a) Total redistribution coefficient, based on the proportional distribution of all the defined causes originally notified and b) Non-external redistribution coefficient, similar to the previous, but excluding external causes. RESULTS Of the 97,314 deaths by ill-defined causes reported in 2010, 30.3% were investigated, and 65.5% of those were reclassified as defined causes after the investigation. Endocrine diseases, mental disorders, and maternal causes had a higher representation among the reclassified ill-defined causes, contrary to infectious diseases, neoplasms, and genitourinary diseases, with higher proportions among the defined causes reported. External causes represented 9.3% of the ill-defined causes reclassified. The correction of mortality rates by the total redistribution coefficient and non-external redistribution coefficient increased the magnitude of the rates by a relatively similar factor for most causes, contrary to the IDCD redistribution coefficient that corrected the different causes of death with differentiated weights. CONCLUSIONS The proportional distribution of causes among the ill-defined causes reclassified after investigation was not similar to the original distribution of defined causes. Therefore, the redistribution of the remaining ill-defined causes based on the investigation allows for more appropriate estimates of the mortality risk due to specific causes. PMID:25210826

Ill-defined causes of death in Brazil: a redistribution method based on the investigation of such causes.

PubMed

França, Elisabeth; Teixeira, Renato; Ishitani, Lenice; Duncan, Bruce Bartholow; Cortez-Escalante, Juan José; Morais Neto, Otaliba Libânio de; Szwarcwald, Célia Landman

2014-08-01

OBJECTIVE To propose a method of redistributing ill-defined causes of death (IDCD) based on the investigation of such causes. METHODS In 2010, an evaluation of the results of investigating the causes of death classified as IDCD in accordance with chapter 18 of the International Classification of Diseases (ICD-10) by the Mortality Information System was performed. The redistribution coefficients were calculated according to the proportional distribution of ill-defined causes reclassified after investigation in any chapter of the ICD-10, except for chapter 18, and used to redistribute the ill-defined causes not investigated and remaining by sex and age. The IDCD redistribution coefficient was compared with two usual methods of redistribution: a) Total redistribution coefficient, based on the proportional distribution of all the defined causes originally notified and b) Non-external redistribution coefficient, similar to the previous, but excluding external causes. RESULTS Of the 97,314 deaths by ill-defined causes reported in 2010, 30.3% were investigated, and 65.5% of those were reclassified as defined causes after the investigation. Endocrine diseases, mental disorders, and maternal causes had a higher representation among the reclassified ill-defined causes, contrary to infectious diseases, neoplasms, and genitourinary diseases, with higher proportions among the defined causes reported. External causes represented 9.3% of the ill-defined causes reclassified. The correction of mortality rates by the total redistribution coefficient and non-external redistribution coefficient increased the magnitude of the rates by a relatively similar factor for most causes, contrary to the IDCD redistribution coefficient that corrected the different causes of death with differentiated weights. CONCLUSIONS The proportional distribution of causes among the ill-defined causes reclassified after investigation was not similar to the original distribution of defined causes. Therefore, the redistribution of the remaining ill-defined causes based on the investigation allows for more appropriate estimates of the mortality risk due to specific causes.

Mobile charge, soft breakdown, and self-healing in hydrogen silsesquioxane based intermetal dielectric

NASA Astrophysics Data System (ADS)

Devine, R. A. B.

2002-09-01

The electrical characteristics of hydrogen silsesquioxane based flowable oxide (FOxregistered) films proposed for interconnect isolation applications have been studied. It is demonstrated that negative and positive charges exist in the as-made, cured films with densities of 0.95 x1012 and 1.5 x1012 cm-2, respectively for thicknesses of 114 nm. The negative charges can be removed from the films by application of modest electric fields (positive or negative, approx1.75 MV cm-1). The positive charge can be similarly displaced but not removed from the film; this results in time dependent relaxation and redistribution of the positive charge if the films are left unbiased. Time dependent irreversible evolution of the leakage current under positive and negative bias (approx3 MV cm-1) shows a slow breakdown phenomena. An unusual self-healing effect is evidenced in these films.

Models of Design: Envisioning a Future Design Education

ERIC Educational Resources Information Center

Friedman, Ken

2012-01-01

This article offers a large-scale view of how design fits in the world economy today, and the role of design education in preparing designers for their economic and professional role. The current context of design involves broad-based historical changes including a major redistribution of geopolitical and industrial power from the West to the…

Poverty and Inequality. The Political Economy of Redistribution.

ERIC Educational Resources Information Center

Neill, Jon, Ed.

These six essays on the debate over the need for welfare reform offer a wide perspective on poverty and inequality. The "Introduction" (Jon Neill) is followed by "Welfare Report--1996 Style: Will We Sacrifice the 'Safety Net'?" (Robert Haveman), a critique of two proposals that shaped the current debate over welfare reform.…

Negative differential photoconductance in gold nanoparticle arrays in the Coulomb blockade regime.

PubMed

Mangold, Markus A; Calame, Michel; Mayor, Marcel; Holleitner, Alexander W

2012-05-22

We investigate the photoconductance of gold nanoparticle arrays in the Coulomb blockade regime. Two-dimensional, hexagonal crystals of nanoparticles are produced by self-assembly. The nanoparticles are weakly coupled to their neighbors by a tunneling conductance. At low temperatures, the single electron charging energy of the nanoparticles dominates the conductance properties of the array. The Coulomb blockade of the nanoparticles can be lifted by optical excitation with a laser beam. The optical excitation leads to a localized heating of the arrays, which in turn gives rise to a local change in conductance and a redistribution of the overall electrical potential in the arrays. We introduce a dual-beam optical excitation technique to probe the distribution of the electrical potential in the nanoparticle array. A negative differential photoconductance is the direct consequence of the redistribution of the electrical potential upon lifting of the Coulomb blockade. On the basis of our model, we calculate the optically induced current from the dark current-voltage characteristics of the nanoparticle array. The calculations closely reproduce the experimental observations.

Near-bottom circulation and dispersion of sediment containing Alexandrium fundyense cysts in the Gulf of Maine during 2010-2011

USGS Publications Warehouse

Aretxabaleta, Alfredo L.; Butman, Bradford; Signell, Richard P.; Dalyander, P. Soupy; Sherwood, Christopher R.; Sheremet, Vitalii A.; McGillicuddy, Dennis J.

2014-01-01

The life cycle of Alexandrium fundyense in the Gulf of Maine includes a dormant cyst stage that spends the winter predominantly in the bottom sediment. Wave-current bottom stress caused by storms and tides induces resuspension of cyst-containing sediment during winter and spring. Resuspended sediment could be transported by water flow to different locations in the Gulf and the redistribution of sediment containing A. fundyense cysts could alter the spatial and temporal manifestation of its spring bloom. The present study evaluates model near-bottom flow during storms, when sediment resuspension and redistribution are most likely to occur, between October and May when A. fundyense cells are predominantly in cyst form. Simulated water column sediment (mud) concentrations from representative locations of the Gulf are used to initialize particle tracking simulations for the period October 2010–May 2011. Particles are tracked in full three-dimensional model solutions including a sinking velocity characteristic of cyst and aggregated mud settling (0.1 mm s−1). Although most of the material was redeposited near the source areas, small percentages of total resuspended sediment from some locations in the western (~4%) and eastern (2%) Maine shelf and the Bay of Fundy (1%) traveled distances longer than 100 km before resettling. The redistribution changed seasonally and was sensitive to the prescribed sinking rate. Estimates of the amount of cysts redistributed with the sediment were small compared to the inventory of cysts in the upper few centimeters of sediment but could potentially have more relevance immediately after deposition.

The combined effects of topography and vegetation on catchment connectivity

NASA Astrophysics Data System (ADS)

Nippgen, F.; McGlynn, B. L.; Emanuel, R. E.

2012-12-01

The deconvolution of whole catchment runoff response into its temporally dynamic source areas is a grand challenge in hydrology. The extent to which the intersection of static and dynamic catchment characteristics (e.g. topography and vegetation) influences water redistribution within a catchment and the hydrologic connectivity of hillslopes to the riparian and stream system is largely unknown. Over time, patterns of catchment storage shift and, because of threshold connectivity behavior, catchment areas become disconnected from the stream network. We developed a simple but spatially distributed modeling framework that explicitly incorporates static (topography) and dynamic (vegetation) catchment structure to document the evolution of catchment connectivity over the course of a water year. We employed directly measured eddy-covariance evapotranspiration data co-located within a highly instrumented (>150 recording groundwater wells) and gauged catchment to parse the effect of current and zero vegetation scenarios on the temporal evolution of hydrologic connectivity. In the absence of vegetation, and thus in the absence of evapotranspiration, modeled absolute connectivity was 4.5% greater during peak flow and 3.9% greater during late summer baseflow when compared to the actual vegetation scenario. The most significant differences in connected catchment area between current and zero vegetation (14.9%) occurred during the recession period in early July, when water and energy availability were at an optimum. However, the greatest relative difference in connected area occurs during the late summer baseflow period when the absence of evapotranspiration results in a connected area approximately 500% greater than when vegetation is present, while the relative increase during peak flow is just 6%. Changes in connected areas ultimately lead to propose a biologically modified geomorphic width function. This biogeomorphic width function is the result of lateral water redistribution driven by topography and water uptake by vegetation.

Self-organized dynamics in local load-sharing fiber bundle models.

PubMed

Biswas, Soumyajyoti; Chakrabarti, Bikas K

2013-10-01

We study the dynamics of a local load-sharing fiber bundle model in two dimensions under an external load (which increases with time at a fixed slow rate) applied at a single point. Due to the local load-sharing nature, the redistributed load remains localized along the boundary of the broken patch. The system then goes to a self-organized state with a stationary average value of load per fiber along the (increasing) boundary of the broken patch (damaged region) and a scale-free distribution of avalanche sizes and other related quantities are observed. In particular, when the load redistribution is only among nearest surviving fiber(s), the numerical estimates of the exponent values are comparable with those of the Manna model. When the load redistribution is uniform along the patch boundary, the model shows a simple mean-field limit of this self-organizing critical behavior, for which we give analytical estimates of the saturation load per fiber values and avalanche size distribution exponent. These are in good agreement with numerical simulation results.

Trends and techniques for space base electronics. [mathematical models, ion implantation, and semiconductors

NASA Technical Reports Server (NTRS)

Gassaway, J. D.; Mahmood, Q.; Trotter, J. D.

1978-01-01

A system was developed for depositing aluminum and aluminum alloys by the D.C. sputtering technique. This system which was designed for a high level of cleanliness and ion monitoring the deposition parameters during film preparation is ready for studying the deposition and annealing parameters upon double level metal preparation. The finite element method was studied for use in the computer modeling of two dimensional MOS transistor structures. An algorithm was developed for implementing a computer study which is based upon the finite difference method. The program was modified and used to calculate redistribution data for boron and phosphorous which had been predeposited by ion implantation with range and straggle conditions typical of those used at MSFC. Data were generated for 111 oriented SOS films with redistribution in N2, dry O2 and steam ambients. Data are given showing both two dimensional effects and the evolution of the junction depth, sheet resistance and integrated dose with redistribution time.

Effects of Cluster Sets and Rest-Redistribution on Mechanical Responses to Back Squats in Trained Men.

PubMed

Tufano, James J; Conlon, Jenny A; Nimphius, Sophia; Brown, Lee E; Petkovic, Alex; Frick, Justin; Haff, G Gregory

2017-09-01

Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or main effect was present for MF. During RR1, MV, PV, MP, and PP were maintained, but decreased throughout every 4-repetition sequence during CS4 and RR4. During CS4 and RR4, PF was less following a rest period compared to subsequent repetitions, whereas PF was maintained during RR1. These data indicate that rest redistribution results in similar average kinetics and kinematics, but if total rest time is redistributed to create shorter but more frequent sets, kinetics and kinematics may remain more constant.

Effects of Cluster Sets and Rest-Redistribution on Mechanical Responses to Back Squats in Trained Men

PubMed Central

Tufano, James J.; Conlon, Jenny A.; Nimphius, Sophia; Brown, Lee E.; Petkovic, Alex; Frick, Justin; Haff, G. Gregory

2017-01-01

Abstract Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or main effect was present for MF. During RR1, MV, PV, MP, and PP were maintained, but decreased throughout every 4-repetition sequence during CS4 and RR4. During CS4 and RR4, PF was less following a rest period compared to subsequent repetitions, whereas PF was maintained during RR1. These data indicate that rest redistribution results in similar average kinetics and kinematics, but if total rest time is redistributed to create shorter but more frequent sets, kinetics and kinematics may remain more constant. PMID:28828076

Transport of Indole-3-Acetic Acid during Gravitropism in Intact Maize Coleoptiles 1

PubMed Central

Parker, Karen E.; Briggs, Winslow R.

1990-01-01

We have investigated the transport of tritiated indole-3-acetic acid (IAA) in intact, red light-grown maize (Zea mays) coleoptiles during gravitropic induction and the subsequent development of curvature. This auxin is transported down the length of gravistimulated coleoptiles at a rate comparable to that in normal, upright plants. Transport is initially symmetrical across the coleoptile, but between 30 and 40 minutes after plants are turned horizontal a lateral redistribution of the IAA already present in the transport stream occurs. By 60 minutes after the beginning of the gravitropic stimulus, the ratio of tritiated tracer auxin in the lower half with respect to the upper half is approximately 2:1. The redistribution of growth that causes gravitropic curvature follows the IAA redistribution by 5 or 10 minutes at the minimum in most regions of the coleoptile. Immobilization of tracer auxin from the transport stream during gravitropism was not detectable in the most apical 10 millimeters. Previous reports have shown that in intact, red light-grown maize coleoptiles, endogenous auxin is limiting for growth, the tissue is linearly responsive to linearly increasing concentrations of small amounts of added auxin, and the lag time for the stimulation of straight growth by added IAA is approximately 8 or 9 minutes (TI Baskin, M Iino, PB Green, WR Briggs [1985] Plant Cell Environ 8: 595-603; TI Baskin, WR Briggs, M Iino [1986] Plant Physiol 81: 306-309). We conclude that redistribution of IAA in the transport stream occurs in maize coleoptiles during gravitropism, and is sufficient in degree and timing to be the immediate cause of gravitropic curvature. PMID:16667914

Catchment-scale redistribution of lithogenic solutes and black carbon over three years following wildfire in the Jemez Mountains, New Mexico, USA

NASA Astrophysics Data System (ADS)

Pohlmann, M. A.; Root, R.; Abrell, L.; Schwartz, C. J.; Chorover, J.

2017-12-01

Wildfire represents a disturbance that is becoming more prevalent as climate shifts to hotter and drier conditions in the southwestern US. It has profound and potentially long-term effects on the physical, chemical and microbiological properties of soil, including immediate surface deposition of lithogenic elements and incompletely combusted organic matter (i.e., black carbon or BC) previously held in biomass. The long residence time of BC mitigates oxidative release of carbon to the atmosphere and thus has implications for long-term climate forcing. Immediately following the 2013 Thompson Ridge wildfire in the Jemez River Basin Critical Zone Observatory, we sampled 22 soil profiles across a zero order basin at finely resolved depth intervals to 40 cm. Samples were collected again 12 and 24 months following the fire to assess redistribution of solutes and BC in the two years following fire. Water extractable anions, cations and carbon were measured for each sample and maps were generated by geostatistical interpolation. Additionally, the benzene polycarboxylic acid (BPCA) molecular marker method was employed for a selection of samples to quantify and characterize the BC content of the existing soil organic carbon pool as a function of landscape position and time. The `pulsed' deposition of water-soluble ions and BC followed pre-fire vegetation structure as indicated by solution chemistry data for years one and two displaying elevated solute concentrations in surface depths proximal to dense vegetation. Vertical and lateral redistribution of the water extractable elements and BC were consistent with wetting front propagation and topographic trends (driven by erosion, overland flow and lateral subsurface flow). BC depth profiles indicate vertical infiltration and lateral transport with burial, the latter associated with surface erosion of sediment, as mechanisms for redistribution.

California State Waters Map Series: Drakes Bay and vicinity, California

USGS Publications Warehouse

Watt, Janet T.; Dartnell, Peter; Golden, Nadine E.; Greene, H. Gary; Erdey, Mercedes D.; Cochrane, Guy R.; Johnson, Samuel Y.; Hartwell, Stephen R.; Kvitek, Rikk G.; Manson, Michael W.; Endris, Charles A.; Dieter, Bryan E.; Sliter, Ray W.; Krigsman, Lisa M.; Lowe, Erik N.; Chinn, John L.; Watt, Janet T.; Cochran, Susan A.

2015-01-01

Sediment transport in the map area largely is controlled by surface waves and tidal currents in the nearshore and, at depths greater than 20 to 30 m, by tidal and subtidal currents. In the map area, nearshore littoral drift of sand and coarse sediment is to the south, owing to the dominant west-northwest swell direction, and scour from large waves and tidal currents removes and redistributes sediment over large areas of the inner shelf. Tidal currents are particularly strong over the shelf in the map area, and they dominate the current regime in the nearshore. Further offshore, bottom currents generally flow to the northwest, distributing finer grained sediment accordingly.

A 'dynamic' landscape of fear: prey responses to spatiotemporal variations in predation risk across the lunar cycle.

PubMed

Palmer, M S; Fieberg, J; Swanson, A; Kosmala, M; Packer, C

2017-11-01

Ambiguous empirical support for 'landscapes of fear' in natural systems may stem from failure to consider dynamic temporal changes in predation risk. The lunar cycle dramatically alters night-time visibility, with low luminosity increasing hunting success of African lions. We used camera-trap data from Serengeti National Park to examine nocturnal anti-predator behaviours of four herbivore species. Interactions between predictable fluctuations in night-time luminosity and the underlying risk-resource landscape shaped herbivore distribution, herding propensity and the incidence of 'relaxed' behaviours. Buffalo responded least to temporal risk cues and minimised risk primarily through spatial redistribution. Gazelle and zebra made decisions based on current light levels and lunar phase, and wildebeest responded to lunar phase alone. These three species avoided areas where likelihood of encountering lions was high and changed their behaviours in risky areas to minimise predation threat. These patterns support the hypothesis that fear landscapes vary heterogeneously in both space and time. © 2017 John Wiley & Sons Ltd/CNRS.

Analysis of TIMED/GUVI Dayglow Utraviolet Oxygen Images

NASA Astrophysics Data System (ADS)

Christensen, A. B.; Crowley, G.; Meier, R.

2016-12-01

Analysis of the atomic oxygen resonance transition at 130.4 nm and the inter-combination transition at 135.6 nm measured by the TIMED/GUVI mission demonstrates the state of knowledge of these important dayglow emission features and the degree to which current models can simulate their global properties. The complete modeling framework comprises several models, including the Thermosphere ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM), Assimilative Mapping of Ionospheric Electrodynamics (AMIE), a partial frequency redistribution resonance scattering model usually called REDISTER needed to compute the optically thick radiative transfer of the 130.4 nm emission, airglow emission models, GLOW and AURIC and other procedures. Observations for four different days, collected under different geophysical conditions of magnetic activity and solar cycle, show very good agreement with the calculated emission brightness and geographic distribution for both emissions. The differences between the airglow codes for the 135.6 nm emission will be discussed in connection to the photoelectron energy loss cross sections, as well as the excitation cross sections used in the various models.

Spring Melt and the Redistribution of Organochlorine Pesticides in the Sea-Ice Environment: A Comparative Study between Arctic and Antarctic Regions.

PubMed

Bigot, Marie; Hawker, Darryl W; Cropp, Roger; Muir, Derek Cg; Jensen, Bjarne; Bossi, Rossana; Bengtson Nash, Susan M

2017-08-15

Complementary sampling of air, snow, sea-ice, and seawater for a range of organochlorine pesticides (OCPs) was undertaken through the early stages of respective spring sea-ice melting at coastal sites in northeast Greenland and eastern Antarctica to investigate OCP concentrations and redistribution during this time. Mean concentrations in seawater, sea-ice and snow were generally greater at the Arctic site. For example, α-HCH was found to have the largest concentrations of all analytes in Arctic seawater and sea-ice meltwater samples (224-253 and 34.7-48.2 pg·L -1 respectively compared to 1.0-1.3 and <0.63 pg·L -1 respectively for Antarctic samples). Differences in atmospheric samples were generally not as pronounced however. Findings suggest that sea-ice OCP burdens originate from both snow and seawater. The distribution profile between seawater and sea-ice showed a compound-dependency for Arctic samples not evident with those from the Antarctic, possibly due to full submersion of sea-ice at the former. Seasonal sea-ice melt processes may alter the exchange rates of selected OCPs between air and seawater, but are not expected to reverse their direction, which fugacity modeling indicates is volatilisation in the Arctic and net deposition in the Antarctic. These predictions are consistent with the limited current observations.

European Gravity Service for Improved Emergency Management - Status and project highlights

NASA Astrophysics Data System (ADS)

Mayer-Guerr, Torsten; Adrian, Jäggi; Meyer, Ulrich; Jean, Yoomin; Susnik, Andreja; Weigelt, Matthias; van Dam, Tonie; Flechtner, Frank; Gruber, Christian; Güntner, Andreas; Gouweleeuw, Ben; Kvas, Andreas; Klinger, Beate; Flury, Jakob; Bruinsma, Sean; Lemoine, Jean-Michel; Zwenzner, Hendrik; Bourgogne, Stephane; Bandikova, Tamara

2016-04-01

The European Gravity Service for Improved Emergency Management (EGSIEM) is a project of the Horizon 2020 Framework Programme for Research and Innovation of the European Commission. EGSIEM shall demonstrate that observations of the redistribution of water and ice mass derived from the current GRACE mission, the future GRACE-FO mission, and additional data provide critical and complementary information to more traditional Earth Observation products and open the door for innovative approaches to flood and drought monitoring and forecasting. In the frame of EGSIEM three key services should established: 1) a scientific combination service to deliver the best gravity products for applications in Earth and environmental science research based on the unified knowledge of the European GRACE community, 2) a near real-time and regional service to reduce the latency and increase the temporal resolution of the mass redistribution products, and 3) a hydrological and early warning service to develop gravity-based indicators for extreme hydrological events and to demonstrate their value for flood and drought forecasting and monitoring services. All of these services shall be tailored to the various needs of the respective communities. Significant efforts shall also be devoted to transform the service products into user-friendly and easy-to-interpret data sets and the development of visualization tools. In this talk the status of the ongoing project is presented and selected results are discussed.

Recent results from the electron cyclotron heated plasmas in Tokamak à Configuration Variable (TCV)

NASA Astrophysics Data System (ADS)

Henderson, M. A.; Alberti, S.; Angioni, C.; Arnoux, G.; Behn, R.; Blanchard, P.; Bosshard, P.; Camenen, Y.; Coda, S.; Condrea, I.; Goodman, T. P.; Hofmann, F.; Hogge, J.-Ph.; Karpushov, A.; Manini, A.; Martynov, An.; Moret, J.-M.; Nikkola, P.; Nelson-Melby, E.; Pochelon, A.; Porte, L.; Sauter, O.; Ahmed, S. M.; Andrèbe, Y.; Appert, K.; Chavan, R.; Degeling, A.; Duval, B. P.; Etienne, P.; Fasel, D.; Fasoli, A.; Favez, J.-Y.; Furno, I.; Horacek, J.; Isoz, P.; Joye, B.; Klimanov, I.; Lavanchy, P.; Lister, J. B.; Llobet, X.; Magnin, J.-C.; Marlétaz, B.; Marmillod, P.; Martin, Y.; Mayor, J.-M.; Mylnar, J.; Paris, P. J.; Perez, A.; Peysson, Y.; Pitts, R. A.; Raju, D.; Reimerdes, H.; Scarabosio, A.; Scavino, E.; Seo, S. H.; Siravo, U.; Sushkov, A.; Tonetti, G.; Tran, M. Q.; Weisen, H.; Wischmeier, M.; Zabolotsky, A.; Yhuang, G.

2003-05-01

In noninductively driven discharges, 0.9 MW second harmonic (X2) off-axis co-electron cyclotron current drive deposition is combined with 0.45 MW X2 central heating to create an electron internal transport barrier (eITB) in steady plasma conditions resulting in a 1.6-fold increase of the confinement time (τEe) over ITER-98L-mode scaling. The eITB is associated with a reversed shear current profile enhanced by a large bootstrap current fraction (up to 80%) and is sustained for up to 10 current redistribution times. A linear dependence of the confinement improvement on the product of the global shear reversal factor (q0/qmin) and the reversed shear volume (ρq-min2) is shown. In other discharges heated with X2 the sawteeth are destabilized (respectively stabilized) when heating just inside (respectively outside) the q=1 surface. Control of the sawteeth may allow the avoidance of neoclassical tearing modes that can be seeded by the sawtooth instability. Results on H-mode and highly elongated plasmas using the newly completed third harmonic (X3) system and achieving up to 100% absorption are also discussed, along with comparison of experimental results with the TORAY-GA ray tracing code [K. Matsuda, IEEE Trans. Plasma Sci. PS-17, 6 (1989); R. H. Cohen, Phys. Fluids 30, 2442 (1987)].

Measuring flows in the solar interior: current developments, results, and outstanding problems

NASA Astrophysics Data System (ADS)

Schad, Ariane

2016-10-01

I will present an overview of the current developments to determine flows in the solar interior and recent results from helioseismology. I will lay special focus on the inference of the deep structure of the meridional flow, which is one of the most challenging problems in helioseismology. In recent times, promising approaches have been developed for solving this problem. The time-distance analysis made large improvements in this after becoming aware of and compensating for a systematic effect in the analysis, the origin of which is not clear yet. In addition to this, a different approach is now available, which directly exploits the distortion of mode eigenfunctions by the meridional flow as well as rotation. These methods have presented us partly surprisingly complex meridional flow patterns, which, however, do not provide a consistent picture of the flow. Resolving this puzzle is part of current research since this has important consequences on our understanding of the solar dynamo. Another interesting discrepancy was found in recent studies between the amplitudes of the large- and small-scale dynamics in the convection zone estimated from helioseismology and those predicted from theoretical models. This raises fundamental questions how the Sun, and in general a star, maintains its heat transport and redistributes its angular momentum that lead, e.g., to the observed differential rotation.

Quantification of colloidal and aqueous element transfer in soils: The dual-phase mass balance model

USGS Publications Warehouse

Bern, Carleton R.; Thompson, Aaron; Chadwick, Oliver A.

2015-01-01

Mass balance models have become standard tools for characterizing element gains and losses and volumetric change during weathering and soil development. However, they rely on the assumption of complete immobility for an index element such as Ti or Zr. Here we describe a dual-phase mass balance model that eliminates the need for an assumption of immobility and in the process quantifies the contribution of aqueous versus colloidal element transfer. In the model, the high field strength elements Ti and Zr are assumed to be mobile only as suspended solids (colloids) and can therefore be used to distinguish elemental redistribution via colloids from redistribution via dissolved aqueous solutes. Calculations are based upon element concentrations in soil, parent material, and colloids dispersed from soil in the laboratory. We illustrate the utility of this model using a catena in South Africa. Traditional mass balance models systematically distort elemental gains and losses and changes in soil volume in this catena due to significant redistribution of Zr-bearing colloids. Applying the dual-phase model accounts for this colloidal redistribution and we find that the process accounts for a substantial portion of the major element (e.g., Al, Fe and Si) loss from eluvial soil. In addition, we find that in illuvial soils along this catena, gains of colloidal material significantly offset aqueous elemental loss. In other settings, processes such as accumulation of exogenous dust can mimic the geochemical effects of colloid redistribution and we suggest strategies for distinguishing between the two. The movement of clays and colloidal material is a major process in weathering and pedogenesis; the mass balance model presented here is a tool for quantifying effects of that process over time scales of soil development.

A study of dynamic data placement for ATLAS distributed data management

NASA Astrophysics Data System (ADS)

Beermann, T.; Stewart, G. A.; Maettig, P.

2015-12-01

This contribution presents a study on the applicability and usefulness of dynamic data placement methods for data-intensive systems, such as ATLAS distributed data management (DDM). In this system the jobs are sent to the data, therefore having a good distribution of data is significant. Ways of forecasting workload patterns are examined which then are used to redistribute data to achieve a better overall utilisation of computing resources and to reduce waiting time for jobs before they can run on the grid. This method is based on a tracer infrastructure that is able to monitor and store historical data accesses and which is used to create popularity reports. These reports provide detailed summaries about data accesses in the past, including information about the accessed files, the involved users and the sites. From this past data it is possible to then make near-term forecasts for data popularity in the future. This study evaluates simple prediction methods as well as more complex methods like neural networks. Based on the outcome of the predictions a redistribution algorithm deletes unused replicas and adds new replicas for potentially popular datasets. Finally, a grid simulator is used to examine the effects of the redistribution. The simulator replays workload on different data distributions while measuring the job waiting time and site usage. The study examines how the average waiting time is affected by the amount of data that is moved, how it differs for the various forecasting methods and how that compares to the optimal data distribution.

Vulnerability of high-latitude soil organic carbon in North America to disturbance

Treesearch

Guido Grosse; Jennifer Harden; Merritt Turetsky; A. David McGuire; Philip Camill; Charles Tarnocai; Steve Frolking; Edward Schuur; Torre Jorgenson; Sergei Marchenko; Vladimir Romanovsky; Kimberly P. Wickland; Nancy French; Mark Waldrop; Laura Bourgeau-Chavez; Robert G. Streigl

2011-01-01

This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools...

Predicting abundance of 80 tree species following climate change in the Eastern United States

Treesearch

Louis R. Iverson; Anantha M. Prasad; Anantha M. Prasad

1998-01-01

Projected climate warming will potentially have profound effects on the earth?s biota, including a large redistribution of tree species. We developed models to evaluate potential shifts for 80 individual tree species in the eastern United States. First, environmental factors associated with current ranges of tree species were assessed using geographic information...

Coping Strategies of Part-Time MBA Students: The Role of Boundary Management

ERIC Educational Resources Information Center

Dunagan, Marion

2012-01-01

Using the framework of boundary theory as applied to the work-life-school construct, the study focused on part-time MBA students who worked full-time, their tendency to segment or integrate their numerous roles, and the coping tactics they utilized in redistributing their efforts as they added graduate school to these roles. The research…

Collective religiosity and the gender gap in attitudes towards economic redistribution in 86 countries, 1990-2008.

PubMed

Jaime-Castillo, Antonio M; Fernández, Juan J; Valiente, Celia; Mayrl, Damon

2016-05-01

What is the relationship between gender and the demand for redistribution? Because, on average, women face more economic deprivation than men, in many countries women favor redistribution more than men. However, this is not the case in a number of other countries, where women do not support redistribution more than men. To explain this cross-national paradox, we stress the role of collective religiosity. In many religions, theological principles both militate against public policies designed to redistribute income, and also promote traditionally gendered patterns of work and family involvement. Hence, we hypothesize that, in those countries where religion remains influential either through closer church-state ties or an intensely religious population, men and women should differ less in their attitudes towards redistribution. Drawing upon the World Values Survey, we estimate three-level regression models that test our religiosity-based approach and two alternative explanations in 86 countries and 175 country-years. The results are consistent with our hypothesis. Moreover, in further support of our theoretical approach, societal religiosity undermines pro-redistribution preferences more among women than men. Our findings suggest that collective religiosity matters more to the gender gap in redistributive attitudes than traditional political and labor force factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of nuclear cardiology in evaluating the total ischemic burden in coronary artery disease

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

Beller, G.A.

1987-03-09

Goals of exercise radionuclide imaging are to: enhance sensitivity, specificity and predictive value of coronary artery disease (CAD) detection; noninvasively assess extent and severity of functionally significant CAD; determine prognosis so that specific therapeutic strategies can be more rationally implemented; detect silent ischemia in asymptomatic subjects or in patients with known CAD with a higher degree of specificity than can be accomplished by electrocardiogram stress testing alone; evaluate the response to therapeutic interventions aimed at enhancing coronary blood flow. Two major radionuclide techniques are currently used in evaluating the total ischemic burden in patients with CAD. These are myocardial perfusionmore » imaging with either thallium-201 or rubidium-82, and radionuclide angiography performed after administration of technetium-99m. Areas of diminished thallium-201 activity on early postexercise images are abnormal and represent either areas of stress-induced ischemia or myocardial scar. To differentiate between the two, delayed images are obtained to determine if the initial postexercise defect either persists or demonstrates redistribution. Defects demonstrating redistribution represent transient ischemia, whereas areas of previous infarction or scar usually appear as persistent defects. Patients with left main or 3-vessel CAD usually show multiple thallium-201 redistribution defects in more than 1 vascular supply region, a phenomenon often associated with abnormal lung thallium-201 uptake.« less

Use of (137)Cs technique for soil erosion study in the agricultural region of Casablanca in Morocco.

PubMed

Nouira, A; Sayouty, E H; Benmansour, M

2003-01-01

Accelerated erosion and soil degradation currently cause serious problems to the Oued El Maleh basin (Morocco). Furthermore, there is still only limited information on rates of soil loss for optimising strategies for soil conservation. In the present study we have used the (137)Cs technique to assess the soil erosion rates on an agricultural land in Oued el Maleh basin near Casablanca (Morocco). A small representative agricultural field was selected to investigate the soil degradation required by soil managers in this region. The transect approach was applied for sampling to identify the spatial redistribution of (137)Cs. The spatial variability of (137)Cs inventory has provided evidence of the importance of tillage process and the human effects on the redistribution of (137)Cs. The mean (137)Cs inventory was found about 842 Bq m(-2), this value corresponds to an erosion rate of 82 tha(-1) yr(-1) by applying simplified mass balance model in a preliminary estimation. When data on site characteristics were available, the refined mass balance model was applied to highlight the contribution of tillage effect in soil redistribution. The erosion rate was estimated about 50 tha(-1) yr(-1). The aspects related to the sampling procedures and the models for calculation of erosion rates are discussed.

Electron energy distributions measured during electron beam/plasma interactions. [in E region

NASA Technical Reports Server (NTRS)

Jost, R. J.; Anderson, H. R.; Mcgarity, J. O.

1980-01-01

In the large vacuum facility at the NASA-Johnson Space Center an electron beam was projected 20 m parallel to B from a gun with variable accelerating potential (1.0 to 2.5 kV) to an aluminum target. The ionospheric neutral pressure and field were approximated. Beam electron energy distributions were measured directly using an electrostatic deflection analyzer and indirectly with a detector that responded to the X-rays produced by electron impact on the target. At low currents the distribution is sharply peaked at the acceleration potential. At high currents a beam plasma discharge occurs and electrons are redistributed in energy so that the former energy peak broadens to 10-15 percent FWHM with a strongly enhanced low energy tail. At the 10% of maximum point the energy spectrum ranges from less than 1/2 to 1.2 times the gun energy. The effect is qualitatively the same at all pitch angles and locations sampled.

Effects of income redistribution on the evolution of cooperation in spatial public goods games

NASA Astrophysics Data System (ADS)

Pei, Zhenhua; Wang, Baokui; Du, Jinming

2017-01-01

Income redistribution is the transfer of income from some individuals to others directly or indirectly by means of social mechanisms, such as taxation, public services and so on. Employing a spatial public goods game, we study the influence of income redistribution on the evolution of cooperation. Two kinds of evolutionary models are constructed, which describe local and global redistribution of income respectively. In the local model, players have to pay part of their income after each PGG and the accumulated income is redistributed to the members. While in the global model, all the players pay part of their income after engaging in all the local PGGs, which are centred on himself and his nearest neighbours, and the accumulated income is redistributed to the whole population. We show that the cooperation prospers significantly with increasing income expenditure proportion in the local redistribution of income, while in the global model the situation is opposite. Furthermore, the cooperation drops dramatically from the maximum curvature point of income expenditure proportion. In particular, the intermediate critical points are closely related to the renormalized enhancement factors.

Simulating the Dependence of Sagebrush Steppe Vegetation on Redistributed Snow in a Semi-Arid Watershed.

NASA Astrophysics Data System (ADS)

Soderquist, B.; Kavanagh, K.; Link, T. E.; Strand, E. K.; Seyfried, M. S.

2014-12-01

In mountainous regions across the western USA, the composition of aspen (Populus tremuloides) and sagebrush steppe plant communities is often closely related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) and critical zone observatory (CZO) in southwest Idaho provides a unique opportunity to study the relationship between vegetation types and redistributed snow. Within the RCEW, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. As shifts in precipitation phase continue, future trends in vegetation composition and net primary productivity (NPP) of different plant functional types remains a critical question. We hypothesize that redistribution of snow may supplement drought sensitive species like aspen more so than drought tolerant species like mountain big sagebrush (Artemisia tridentata spp. vaseyana). To assess the importance of snowdrift subsidies on sagebrush steppe vegetation, NPP of aspen, shrub, and grass species was simulated at three sites using the biogeochemical process model BIOME-BGC. Each site is located directly downslope from snowdrifts providing soil moisture inputs to aspen stands and neighboring vegetation. Drifts vary in size with the largest containing up to four times the snow water equivalent (SWE) of a uniform precipitation layer. Precipitation inputs used by BIOME-BGC were modified to represent the redistribution of snow and simulations were run using daily climate data from 1985-2013. Simulated NPP of annual grasses at each site was not responsive to subsidies from drifting snow. However, at the driest site, aspen and shrub annual NPP was increased by as much as 44 and 30%, respectively, with the redistribution of snow. These results indicate that as snow water subsidies decrease, ecosystems may shift from tree and shrub dominated to grassland dominated. As climate change progresses, shifts in the precipitation regimes in semi-arid environments may lead to changes in species composition and carbon stores throughout the intermountain west.

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

Perez-Becker, Daniel; Showman, Adam P.

Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—and thus have a larger day-night temperature contrast—than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a shallow-water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiationmore » exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, τ{sub wave}, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τ{sub wave}∼√(τ{sub rad}/Ω), where τ{sub rad} is the radiative relaxation time and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed as τ{sub rad} ∼ τ{sub vert}, where τ{sub vert} is the timescale for a fluid parcel to move vertically over the difference in day-night thickness. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τ{sub rad} and the horizontal day-night advection timescale, τ{sub adv}. Only because τ{sub adv} ∼ τ{sub vert} for hot Jupiters does the commonly assumed timescale comparison between τ{sub rad} and τ{sub adv} yield approximately correct predictions for the heat redistribution efficiency.« less

Gravitropism: interaction of sensitivity modulation and effector redistribution

NASA Technical Reports Server (NTRS)

Evans, M. L.

1991-01-01

Our increasing capabilities for quantitative hormone analysis and automated high resolution growth studies have allowed a reassessment of the classical Cholodny-Went hypothesis of gravitropism. According to this hypothesis, gravity induces redistribution of auxin toward the lower side of the organ and this causes the growth asymmetry that leads to reorientation. Arguments against the Cholodny-Went hypothesis that were based primarily on concerns over the timing and magnitude of the development of hormone asymmetry are countered by recent evidence that such asymmetry develops early and is sufficiently large to account for curvature. Thus, it appears that the Cholodny-Went hypothesis is fundamentally valid. However, recent comparative studies of the kinetics of curvature and the timing of the development of hormone asymmetry indicate that this hypothesis alone cannot account for the intricacies of the gravitropic response. It appears that time-dependent gravity-induced changes in hormone sensitivity as well as changes in sensitivity of the gravity receptor play important roles in the response.

Gravitropism: Interaction of Sensitivity Modulation and Effector Redistribution 1

PubMed Central

Evans, Michael L.

1991-01-01

Our increasing capabilities for quantitative hormone analysis and automated high resolution growth studies have allowed a reassessment of the classical Cholodny-Went hypothesis of gravitropism. According to this hypothesis, gravity induces redistribution of auxin toward the lower side of the organ and this causes the growth asymmetry that leads to reorientation. Arguments against the Cholodny-Went hypothesis that were based primarily on concerns over the timing and magnitude of the development of hormone asymmetry are countered by recent evidence that such asymmetry develops early and is sufficiently large to account for curvature. Thus, it appears that the Cholodny-Went hypothesis is fundamentally valid. However, recent comparative studies of the kinetics of curvature and the timing of the development of hormone asymmetry indicate that this hypothesis alone cannot account for the intricacies of the gravitropic response. It appears that time-dependent gravity-induced changes in hormone sensitivity as well as changes in sensitivity of the gravity receptor play important roles in the response. PMID:11537485

Polar motion excitation analysis due to global continental water redistribution

NASA Astrophysics Data System (ADS)

Fernandez, L.; Schuh, H.

2006-10-01

We present the results obtained when studying the hydrological excitation of the Earth‘s wobble due to global redistribution of continental water storage. This work was performed in two steps. First, we computed the hydrological angular momentum (HAM) time series based on the global hydrological model LaD (Land Dynamics model) for the period 1980 till 2004. Then, we compared the effectiveness of this excitation by analysing the residuals of the geodetic time series after removing atmospheric and oceanic contributions with the respective hydrological ones. The emphasis was put on low frequency variations. We also present a comparison of HAM time series from LaD with respect to that one from a global model based on the assimilated soil moisture and snow accumulation data from NCEP/NCAR (The National Center for Environmental Prediction/The National Center for Atmospheric Research) reanalysis. Finally, we evaluate the performance of LaD model in closing the polar motion budget at seasonal periods in comparison with the NCEP and the Land Data Assimilation System (LDAS) models.

Managing consequences of climate-driven species redistribution requires integration of ecology, conservation and social science.

PubMed

Bonebrake, Timothy C; Brown, Christopher J; Bell, Johann D; Blanchard, Julia L; Chauvenet, Alienor; Champion, Curtis; Chen, I-Ching; Clark, Timothy D; Colwell, Robert K; Danielsen, Finn; Dell, Anthony I; Donelson, Jennifer M; Evengård, Birgitta; Ferrier, Simon; Frusher, Stewart; Garcia, Raquel A; Griffis, Roger B; Hobday, Alistair J; Jarzyna, Marta A; Lee, Emma; Lenoir, Jonathan; Linnetved, Hlif; Martin, Victoria Y; McCormack, Phillipa C; McDonald, Jan; McDonald-Madden, Eve; Mitchell, Nicola; Mustonen, Tero; Pandolfi, John M; Pettorelli, Nathalie; Possingham, Hugh; Pulsifer, Peter; Reynolds, Mark; Scheffers, Brett R; Sorte, Cascade J B; Strugnell, Jan M; Tuanmu, Mao-Ning; Twiname, Samantha; Vergés, Adriana; Villanueva, Cecilia; Wapstra, Erik; Wernberg, Thomas; Pecl, Gretta T

2018-02-01

Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges. We highlight that species redistribution has manifest implications across multiple temporal and spatial scales and from genes to ecosystems. Understanding range shifts from ecological, physiological, genetic and biogeographical perspectives is essential for informing changing paradigms in conservation science and for designing conservation strategies that incorporate changing population connectivity and advance adaptation to climate change. Species redistributions present challenges for human well-being, environmental management and sustainable development. By synthesising recent approaches, theories and tools, our review establishes an interdisciplinary foundation for the development of future research on species redistribution. Specifically, we demonstrate how ecological, conservation and social research on species redistribution can best be achieved by working across disciplinary boundaries to develop and implement solutions to climate change challenges. Future studies should therefore integrate existing and complementary scientific frameworks while incorporating social science and human-centred approaches. Finally, we emphasise that the best science will not be useful unless more scientists engage with managers, policy makers and the public to develop responsible and socially acceptable options for the global challenges arising from species redistributions. © 2017 Cambridge Philosophical Society.

Water savings of redistributing global crop production

NASA Astrophysics Data System (ADS)

Davis, Kyle; Seveso, Antonio; Rulli, Maria Cristina; D'Odorico, Paolo

2016-04-01

Human demand for crop production is expected to increase substantially in the coming decades as a result of population growth, richer diets and biofuel use. For food production to keep pace, unprecedented amounts of resources - water, fertilizers, energy - will be required. This has led to calls for 'sustainable intensification' in which yields are increased on existing croplands while seeking to minimize impacts on water and other agricultural resources. Recent studies have quantified aspects of this, showing that there is a large potential to improve crop yields and increase harvest frequencies to better meet human demand. Though promising, both solutions would necessitate large additional inputs of water and fertilizer in order to be achieved under current technologies. However, the question of whether the current distribution of crops is, in fact, the best for realizing maximized production has not been considered to date. To this end, we ask: Is it possible to minimize water demand by simply growing crops where soil and climate conditions are best suited? Here we use maps of agro-ecological suitability - a measure of physical and chemical soil fertility - for 15 major food crops to identify differences between current crop distributions and where they can most suitably be planted. By redistributing crops across currently cultivated lands, we determine what distribution of crops would maintain current calorie production and agricultural value while minimizing the water demand of crop production. In doing this, our study provides a novel tool for policy makers and managers to integrate food security, environmental sustainability, and rural livelihoods by improving the use of freshwater resources without compromising crop calorie production or rural livelihoods.

Calorie increase and water savings of redistributing global crop production

NASA Astrophysics Data System (ADS)

Davis, K. F.; Seveso, A.; Rulli, M. C.; D'Odorico, P.

2015-12-01

Human demand for crop production is expected to increase substantially in the coming decades as a result of population growth, richer diets and biofuel use. In order for food production to keep pace, unprecedented amounts of resources - water, fertilizers, energy - will be required. This has led to calls for 'sustainable intensification' in which yields are increased on existing croplands while seeking to minimize impacts on water and other agricultural resources. Recent studies have quantified aspects of this, showing that there is a large potential to improve crop yields and increase harvest frequencies to better meet human demand. Though promising, both solutions would necessitate large additional inputs of water and fertilizer in order to be achieved under current technologies. However, the question of whether the current distribution of crops is, in fact, the best for realizing maximized production has not been considered to date. To this end, we ask: Is it possible to increase calorie production and minimize water demand by simply growing crops where soil and climate conditions are best suited? Here we use maps of agro-ecological suitability - a measure of physical and chemical soil fertility - for 15 major food crops to identify differences between current crop distributions and where they can most suitably be planted. By redistributing crops across currently cultivated lands, we determine the potential improvement in calorie production as well as the associated change in water demand. We also consider what distribution of crops would maintain current calorie production while minimizing crop water demand. In doing all of this, our study provides a novel tool for improving crop calorie production without necessarily increasing resource demands.

The role of vigorous current systems in the Southeast Indian Ocean in redistributing deep-sea sediments

NASA Astrophysics Data System (ADS)

Dutkiewicz, Adriana; Müller, Dietmar; Hogg, Andrew; Spence, Paul

2017-04-01

Understanding the transport of modern deep-sea sediment is critical for accurate models of climate-ocean history and the widespread use of the sedimentological record as a proxy for productivity where the connection between biogenic seafloor lithologies and sea-surface is tenuous. The Southern Ocean, where diatoms contribute the bulk of pelagic material to the seafloor forming an extensive belt of diatom ooze, is an exemplar. However, most of the key studies on large-scale sediment reworking in the Southern Ocean were conducted in the 1970s when relatively little was known about the oceanography of this region. At this time even our knowledge of the bathymetry and tectonic fabric, which underpin the distribution of deep-sea currents, were fairly general. The record of widespread regional disconformities in the abyssal plains of the Southern Ocean is well-established and indicates extensive erosion of deep-sea sediments throughout the Quaternary. Here we combine a high-resolution numerical model of bottom currents with sedimentological data to constrain the redistribution of sediment across the abyssal plains and adjacent mid-ocean ridges in the Southern Ocean. We use the global ocean-sea ice model (GFDL-MOM01) to simulate ocean circulation at a resolution that results in realistic velocities throughout the water column, and is ideal for estimating interaction between time-dependent bottom currents and ocean bathymetry. 230Th-normalized vertical sediment rain rates for 63 sites in the Southeast Indian Ocean, combined with satellite data-derived surface productivity, demonstrate that a wide belt of fast sedimentation rates (> 5.5 cm/kyr) along the Southeast Indian Ridge (SEIR) occurs in a region of low surface productivity bounded by two major disconformity fields associated with the Kerguelen Plateau to the east and the Macquarie Ridge to the west. Our ocean circulation model illustrates that the disconformity fields occur in regions of intense bottom current activity where current speeds reach 0.2 m/s and are favorable for generating intense nepheloid layers. These currents transport sediment towards and along the SEIR and through leaky fracture zones to regions where bottom currents speeds drop to < 0.03 m/s and fine particles settle out of suspension. We suggest that the anomalously high sedimentation rates along an 8,000 km-long segment of the SEIR represent a giant Pliocene-Holocene succession of contourite drifts. It is a major extension of the much smaller contourite east of Kerguelen and has accumulated since 3-5 Ma based on the age of the oldest crust underlying the deposit. These inferred contourite drifts provide exceptionally valuable drilling targets for high-resolution climatic investigations of the Southern Ocean. Understanding and quantifying the link between bottom current activity and sediment transport is critical for paleooceanographic and palaeoclimatic reconstructions and for understanding the history of current flow. Dutkiewicz, A., Müller, R.D., Hogg, A. McC., and Spence, P., 2016, Vigorous deep-sea currents cause global anomaly in sediment accumulation in the Southern Ocean, Geology, 44, 663-666, DOI: 10.1130/G38143.1

A model for discriminating reinforcers in time and space.

PubMed

Cowie, Sarah; Davison, Michael; Elliffe, Douglas

2016-06-01

Both the response-reinforcer and stimulus-reinforcer relation are important in discrimination learning; differential responding requires a minimum of two discriminably-different stimuli and two discriminably-different associated contingencies of reinforcement. When elapsed time is a discriminative stimulus for the likely availability of a reinforcer, choice over time may be modeled by an extension of the Davison and Nevin (1999) model that assumes that local choice strictly matches the effective local reinforcer ratio. The effective local reinforcer ratio may differ from the obtained local reinforcer ratio for two reasons: Because the animal inaccurately estimates times associated with obtained reinforcers, and thus incorrectly discriminates the stimulus-reinforcer relation across time; and because of error in discriminating the response-reinforcer relation. In choice-based timing tasks, the two responses are usually highly discriminable, and so the larger contributor to differences between the effective and obtained reinforcer ratio is error in discriminating the stimulus-reinforcer relation. Such error may be modeled either by redistributing the numbers of reinforcers obtained at each time across surrounding times, or by redistributing the ratio of reinforcers obtained at each time in the same way. We assessed the extent to which these two approaches to modeling discrimination of the stimulus-reinforcer relation could account for choice in a range of temporal-discrimination procedures. The version of the model that redistributed numbers of reinforcers accounted for more variance in the data. Further, this version provides an explanation for shifts in the point of subjective equality that occur as a result of changes in the local reinforcer rate. The inclusion of a parameter reflecting error in discriminating the response-reinforcer relation enhanced the ability of each version of the model to describe data. The ability of this class of model to account for a range of data suggests that timing, like other conditional discriminations, is choice under the joint discriminative control of elapsed time and differential reinforcement. Understanding the role of differential reinforcement is therefore critical to understanding control by elapsed time. Copyright © 2016 Elsevier B.V. All rights reserved.

How Wolf-Rayet winds are driven by starlight and spectral lines

NASA Astrophysics Data System (ADS)

Onifer, Andrew Joseph, III

Finding the cause of the enormous increase in the mass- loss rate of a Wolf-Rayet (W-R) star, as compared to its O star progenitor, has remained a challenge for many years. This thesis explores the hypothesis that line driving causes the large observed W-R mass-loss rates. Frequency redistribution can cause the photons to filter into gaps in the line spectrum, reducing the efficiency of line driving. Therefore, the role that frequency redistribution plays in lowering the predicted mass-loss rate is explored, both via simple two-domain idealizations of the line list and via a real W-R line list. A simple analytic theory, called the Statistical Sobolev Rosseland (SSR) theory, is developed that calculates the local efficiency of line driving in a completely redistributing wind. In the process a conceptual language is developed to explain the key issues in W-R wind line driving. The results are that with no redistribution, the reduction in radius, and corresponding increase in temperature, of an O star as it evolves into a W-R star causes roughly a six-fold increase in the mass-loss rate. However, with large amounts of redistribution, the efficiency of the wind drops greatly in the presence of spectral gaps. In the most extreme case of SSR, the mass- loss rate drops by a factor of up to an order of magnitude relative to the gray value. To avoid this it is necessary to fill the gaps in the spectrum, and the effect that ionization stratification has in filling the gaps globally over the wind is explored. It is found that with the current line list ionization changes can only fill the gaps sufficiently to cause about a factor of two increase over the SSR value. The conclusion is that in order for line driving to explain the mass-loss rates of W-R winds, more opacity needs to be discovered to fill the gaps, either locally, or globally over a realistic range of ionization strata.

Characterization of beam-driven instabilities and current redistribution in MST plasmas

NASA Astrophysics Data System (ADS)

Parke, E.

2015-11-01

A unique, high-rep-rate (>10 kHz) Thomson scattering diagnostic and a high-bandwidth FIR interferometer-polarimeter on MST have enabled characterization of beam-driven instabilities and magnetic equilibrium changes observed during high power (1 MW) neutral beam injection (NBI). While NBI leads to negligible net current drive, an increase in on-axis current density observed through Faraday rotation is offset by a reduction in mid-radius current. Identification of the phase flip in temperature fluctuations associated with tearing modes provides a sensitive measure of rational surface locations. This technique strongly constrains the safety factor for equilibrium reconstruction and provides a powerful new tool for measuring the equilibrium magnetic field. For example, the n = 6 temperature structure is observed to shift inward 1.1 +/- 0.6 cm, with an estimated reduction of q0 by 5%. This is consistent with a mid-radius reduction in current, and together the Faraday rotation and Thomson scattering measurements corroborate an inductive redistribution of current that compares well with TRANSP/MSTFit predictions. Interpreting tearing mode temperature structures in the RFP remains challenging; the effects of multiple, closely-spaced tearing modes on the mode phase measurement require further verification. In addition to equilibrium changes, previous work has shown that the large fast ion population drives instabilities at higher frequencies near the Alfvén continuum. Recent observations reveal a new instability at much lower frequency (~7 kHz) with strongly chirping behavior. It participates in extensive avalanches of the higher frequency energetic particle and Alfvénic modes to drive enhanced fast ion transport. Internal structures measured from Te and ne fluctuations, their dependence on the safety factor, as well as frequency scaling motivate speculation about mode identity. Work supported by U.S. DOE.

Magnetohydrodynamic Convection in the Outer Core and its Geodynamic Consequences

NASA Technical Reports Server (NTRS)

Kuang, Weijia; Chao, Benjamin F.; Fang, Ming

2004-01-01

The Earth's fluid outer core is in vigorous convection through much of the Earth's history. In addition to generating and maintaining Earth s time-varying magnetic field (geodynamo), the core convection also generates mass redistribution in the core and a dynamical pressure field on the core-mantle boundary (CMB). All these shall result in various core-mantle interactions, and contribute to surface geodynamic observables. For example, electromagnetic core-mantle coupling arises from finite electrically conducting lower mantle; gravitational interaction occurs between the cores and the heterogeneous mantle; mechanical coupling may also occur when the CMB topography is aspherical. Besides changing the mantle rotation via the coupling torques, the mass-redistribution in the core shall produce a spatial-temporal gravity anomaly. Numerical modeling of the core dynamical processes contributes in several geophysical disciplines. It helps explain the physical causes of surface geodynamic observables via space geodetic techniques and other means, e.g. Earth's rotation variation on decadal time scales, and secular time-variable gravity. Conversely, identification of the sources of the observables can provide additional insights on the dynamics of the fluid core, leading to better constraints on the physics in the numerical modeling. In the past few years, our core dynamics modeling efforts, with respect to our MoSST model, have made significant progress in understanding individual geophysical consequences. However, integrated studies are desirable, not only because of more mature numerical core dynamics models, but also because of inter-correlation among the geophysical phenomena, e.g. mass redistribution in the outer core produces not only time-variable gravity, but also gravitational core-mantle coupling and thus the Earth's rotation variation. They are expected to further facilitate multidisciplinary studies of core dynamics and interactions of the core with other components of the Earth.

Ubiquitin-dependent distribution of the transcriptional coactivator p300 in cytoplasmic inclusion bodies.

PubMed

Chen, Jihong; Halappanavar, Sabina; Th' ng, John P H; Li, Qiao

2007-01-01

The protein level of transcriptional coactivator p300, an essential nuclear protein, is critical to a broad array of cellular activities including embryonic development, cell differentiation and proliferation. We have previously established that histone deacetylase inhibitor such as valproic acid induces p300 degradation through the 26S proteasome pathway. Here, we report the roles of cellular trafficking and spatial redistribution in valproic acid-induced p300 turnover. Our study demonstrates that p300 is redistributed to the cytoplasm prior to valproic acid-induced turnover. Inhibition of proteasome-dependent protein degradation, does not prevent nucleo-cytoplasmic shuttling of p300, rather sequesters the cytoplasmic p300 to a distinct perinuclear region. In addition, the formation of p300 aggregates in the perinuclear region depends on functional microtubule networks and correlates with p300 ubiquitination. Our work establishes, for the first time, that p300 is also a substrate of the cytoplasmic ubiquitin-proteasome system and provides insight on how cellular trafficking and spatial redistribution regulate the availability and activity of transcriptional coactivator p300.

Intramolecular vibrational energy redistribution and intermolecular energy transfer of benzene in supercritical CO 2: measurements from the gas phase up to liquid densities

NASA Astrophysics Data System (ADS)

von Benten, R.; Charvat, A.; Link, O.; Abel, B.; Schwarzer, D.

2004-03-01

Femtosecond pump probe spectroscopy was employed to measure intramolecular vibrational energy redistribution (IVR) and intermolecular vibrational energy transfer (VET) of benzene in the gas phase and in supercritical (sc) CO 2. We observe two IVR time scales the faster of which proceeds within τ IVR(1)<0.5 ps. The slower IVR component has a time constant of τ IVR(2)=(48±5) ps in the gas phase and in scCO 2 is accelerated by interactions with the solvent. At the highest CO 2 density it is reduced to τ IVR(2)=(6±1) ps. The corresponding IVR rate constants show a similar density dependence as the VET rate constants. Model calculations suggest that both quantities correlate with the local CO 2 density in the immediate surrounding of the benzene molecule.

Measurement-induced-nonlocality for Dirac particles in Garfinkle-Horowitz-Strominger dilation space-time

NASA Astrophysics Data System (ADS)

He, Juan; Xu, Shuai; Ye, Liu

2016-05-01

We investigate the quantum correlation via measurement-induced-nonlocality (MIN) for Dirac particles in Garfinkle-Horowitz-Strominger (GHS) dilation space-time. It is shown that the physical accessible quantum correlation decreases as the dilation parameter increases monotonically. Unlike the case of scalar fields, the physical accessible correlation is not zero when the Hawking temperature is infinite owing to the Pauli exclusion principle and the differences between Fermi-Dirac and Bose-Einstein statistics. Meanwhile, the boundary of MIN related to Bell-violation is derived, which indicates that MIN is more general than quantum nonlocality captured by the violation of Bell-inequality. As a by-product, a tenable quantitative relation about MIN redistribution is obtained whatever the dilation parameter is. In addition, it is worth emphasizing that the underlying reason why the physical accessible correlation and mutual information decrease is that they are redistributed to the physical inaccessible regions.

Study of the effect of sawteeth on fast ions and neutron emission in MAST using a neutron camera

NASA Astrophysics Data System (ADS)

Cecconello, M.; Sperduti, A.; the MAST team

2018-05-01

The effect of the sawtooth instability on the confinement of fast ions on MAST, and the impact it has on the neutron emission, has been studied in detail using the TRANSP/NUBEAM codes coupled to a full orbit following code. The sawtooth models in TRANSP/NUBEAM indicate that, on MAST, passing and trapped fast ions are redistributed in approximately equal number and on a level that is consistent with the observations. It has not been possible to discriminate between the different sawtooth models since their predictions are all compatible with the neutron camera observations. Full orbit calculations of the fast ion motion have been used to estimate the characteristic time scales and energy thresholds that according to theoretical predictions govern the fast ions redistribution: no energy threshold for the redistribution for either passing and trapped fast ions was found. The characteristic times have, however, frequencies that are comparable with the frequencies of a m = 1, n = 1 perturbation and its harmonics with toroidal mode numbers n=2, \\ldots , 4, suggesting that on spherical tokamaks, in addition to the classical sawtooth-induced transport mechanisms of fast ions by attachment to the evolving perturbation and the associated E × B drift, a resonance mechanism between the m = 1 perturbation and the fast ions orbits might be at play.

Does government expenditure reduce inequalities in infant mortality rates in low- and middle-income countries?: A time-series, ecological analysis of 48 countries from 1993 to 2013.

PubMed

Baker, Peter; Hone, Thomas; Reeves, Aaron; Avendano, Mauricio; Millett, Christopher

2018-06-27

Inequalities in infant mortality rates (IMRs) are rising in some low- and middle-income countries (LMICs) and decreasing in others, but the explanation for these divergent trends is unclear. We investigate whether government expenditures and redistribution are associated with reductions in inequalities in IMRs. We estimated country-level fixed-effects panel regressions for 48 LMICs (142 country observations). Slope and Relative Indices of Inequality in IMRs (SII and RII) were calculated from Demographic and Health Surveys between 1993 and 2013. RII and SII were regressed on government expenditure (total, health and non-health) and redistribution, controlling for gross domestic product (GDP), private health expenditures, a democracy indicator, country fixed effects and time. Mean SII and RII was 39.12 and 0.69, respectively. In multivariate models, a 1 percentage point increase in total government expenditure (% of GDP) was associated with a decrease in SII of -2.468 [95% confidence intervals (CIs): -4.190, -0.746] and RII of -0.026 (95% CIs: -0.048, -0.004). Lower inequalities were associated with higher non-health government expenditure, but not higher government health expenditure. Associations with inequalities were non-significant for GDP, government redistribution, and private health expenditure. Understanding how non-health government expenditure reduces inequalities in IMR, and why health expenditures may not, will accelerate progress towards the Sustainable Development Goals.

From microscopic taxation and redistribution models to macroscopic income distributions

NASA Astrophysics Data System (ADS)

Bertotti, Maria Letizia; Modanese, Giovanni

2011-10-01

We present here a general framework, expressed by a system of nonlinear differential equations, suitable for the modeling of taxation and redistribution in a closed society. This framework allows one to describe the evolution of income distribution over the population and to explain the emergence of collective features based on knowledge of the individual interactions. By making different choices of the framework parameters, we construct different models, whose long-time behavior is then investigated. Asymptotic stationary distributions are found, which enjoy similar properties as those observed in empirical distributions. In particular, they exhibit power law tails of Pareto type and their Lorenz curves and Gini indices are consistent with some real world ones.

Organic transistors making use of room temperature ionic liquids as gating medium

NASA Astrophysics Data System (ADS)

Hoyos, Jonathan Javier Sayago

The ability to couple ionic and electronic transport in organic transistors, based on pi conjugated organic materials for the transistor channel, can be particularly interesting to achieve low voltage transistor operation, i.e. below 1 V. The operation voltage in typical organic transistors based on conventional dielectrics (200 nm thick SiO2) is commonly higher than 10 V. Electrolyte-gated (EG) transistors, i.e. employing an electrolyte as the gating medium, permit current modulations of several orders of magnitude at relatively low gate voltages thanks to the exceptionally high capacitance at the electrolyte/transistor channel interface, in turn due to the low thickness (ca. 3 nm) of the electrical double layers forming at the electrolyte/semiconductor interface. Electrolytes based on room temperature ionic liquids (RTILs) are promising in EG transistor applications for their high electrochemical stability and good ionic conductivity. The main motivation behind this work is to achieve low voltage operation in organic transistors by making use of RTILs as gating medium. First we demonstrate the importance of the gate electrode material in the EG transistor performance. The use of high surface area carbon gate electrodes limits undesirable electrochemical processes and renders unnecessary the presence of a reference electrode to monitor the channel potential. This was demonstrated using activated carbon as gate electrode, the electronic conducting polymer MEH-PPV, poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] channel material, and the ionic liquid [EMIM][TFSI] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), as gating medium. Using high surface area gate electrodes resulted in sub-1 V operation and charge carrier mobilities of (1.0 +/- 0.5) x 10-2 cm2V -1s-1. A challenge in the field of EG transistors is to decrease their response time, a consequence of the slow ion redistribution in the transistor channel upon application of electric biases. We systematically investigated EG transistors employing RTILs belonging to the same family, i.e. based on a common anion and different cations. The transistor characteristics showed a limited cation influence in establishing the p-type doping of the conducting polymer. Interestingly, we observed that the transistor response time depends on at least two processes: the redistribution of ions from the electrolyte into the transistor channel, affecting the gate-source current (I gs); and the redistribution of charges in the transistor channel, affecting the drain-source current (Ids), as a function of time. The two processes have different rates, with the latter being the slowest. Incorporating propylene carbonate in the electrolyte proved to be an effective solution to increase the ionic conductivity, to lower the viscosity and, consequently, to reduce the transistor response time. Finally, we were able to demonstrate a multifunctional device integrating the transistor logic function with that of energy storage in a supercapacitor: the TransCap. The polymer/electrolyte/carbon vertical stacking of the EG transistor features the cell configuration of a hybrid supercapacitor. Supercapacitors are high specific power systems that, for their ability to store/deliver charge within short times may outperform batteries in applications having high power demand. When the TransCap is ON (open transistor channel), the polymer and the carbon gate electrodes store charge (Q) at a given Vgs, hence the stored energy equals Q˙V gs. When the TransCap is switched OFF, the channel and the gate are discharged and the energy can be delivered back to power other electronic components. EG transistors, making use of activated carbon as gate electrode and different RTILs as well as RTIL solvent mixtures as electrolyte gating medium, are interesting towards low voltage printable electronics. The high capacitance at the interface between the electrolyte and the transistor channel enables energy storage within the EG transistor architecture.

Impact of recent land use and climate changes on sediment and pollutant redistribution in small catchments within the Seim River Basin (Kursk Region, European Russia)

NASA Astrophysics Data System (ADS)

Belyaev, Vladimir; Ivanova, Nadezda; Ivanov, Maxim; Bondarev, Valery; Lugovoy, Nikolay; Aseeva, Elena; Malyutina, Alisa

2017-04-01

It is widely accepted that changes of land use or climatic conditions can exert profound impacts on river basin sediment budgets and associated particle-bound pollutant redistribution patterns at different temporal and spatial scales. It can be especially difficult to distinguish relative importance of particular factors when the changes occur more or less within the same time frame. Such situation is typical for most parts of the agricultural belt of Russia, as period of economic downfall associated with collapse of the former Soviet Union and later gradual recovery practically coincides with period of the most significant climate changes observed in the late 20th - early 21st Centuries. Therefore it seems interesting and important to consider possible changes of fluvial systems responses within the period from 1980s to the present under different spatial scales. Here we plan to present results of the almost 10-year period of investigations of sediment and associated pollutant redistribution spatial and temporal patterns in several small catchments within the Seim River Basin (Kursk Region, European Russia). Studies dealt with small catchments and small river basins in scales from 1-2 km2 to 200 km2 located in different parts of the main basin. Works carried out included detailed geomorphic surveys, soil and sediment sections and cores description and sampling in different locations (undisturbed, erosion, transit, deposition), remote sensing data and morphometric analysis, soil erosion modeling. Integration of the results allowed constructing sediment budgets, in most cases, for two time intervals (approximately - pre-1986 and post-1986, as the Chernobyl-derived 137Cs has been an important time mark at all the case study sites). It has been found out that combination of several major tendencies including abandonment and recultivation of arable fields, notable decrease of winter-frozen topsoil layer thickness and increase of heavy summer rainstorms magnitude and frequency are responsible for the observed variability of sediment and associated contaminant redistribution patterns.

Enhancing Access to Drought Information Using the CUAHSI Hydrologic Information System

NASA Astrophysics Data System (ADS)

Schreuders, K. A.; Tarboton, D. G.; Horsburgh, J. S.; Sen Gupta, A.; Reeder, S.

2011-12-01

The National Drought Information System (NIDIS) Upper Colorado River Basin pilot study is investigating and establishing capabilities for better dissemination of drought information for early warning and management. As part of this study we are using and extending functionality from the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) to provide better access to drought-related data in the Upper Colorado River Basin. The CUAHSI HIS is a federated system for sharing hydrologic data. It is comprised of multiple data servers, referred to as HydroServers, that publish data in a standard XML format called Water Markup Language (WaterML), using web services referred to as WaterOneFlow web services. HydroServers can also publish geospatial data using Open Geospatial Consortium (OGC) web map, feature and coverage services and are capable of hosting web and map applications that combine geospatial datasets with observational data served via web services. HIS also includes a centralized metadata catalog that indexes data from registered HydroServers and a data access client referred to as HydroDesktop. For NIDIS, we have established a HydroServer to publish drought index values as well as the input data used in drought index calculations. Primary input data required for drought index calculation include streamflow, precipitation, reservoir storages, snow water equivalent, and soil moisture. We have developed procedures to redistribute the input data to the time and space scales chosen for drought index calculation, namely half monthly time intervals for HUC 10 subwatersheds. The spatial redistribution approaches used for each input parameter are dependent on the spatial linkages for that parameter, i.e., the redistribution procedure for streamflow is dependent on the upstream/downstream connectivity of the stream network, and the precipitation redistribution procedure is dependent on elevation to account for orographic effects. A set of drought indices are then calculated from the redistributed data. We have created automated data and metadata harvesters that periodically scan and harvest new data from each of the input databases, and calculates extensions to the resulting derived data sets, ensuring that the data available on the drought server is kept up to date. This paper will describe this system, showing how it facilitates the integration of data from multiple sources to inform the planning and management of water resources during drought. The system may be accessed at http://drought.usu.edu.

Physical and virtual water transfers for regional water stress alleviation in China

PubMed Central

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R.; Guan, Dabo; Hubacek, Klaus

2015-01-01

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management. PMID:25583516

Redistribution of wastewater alkalinity with a microbial fuel cell to support nitrification of reject water.

PubMed

Modin, Oskar; Fukushi, Kensuke; Rabaey, Korneel; Rozendal, René A; Yamamoto, Kazuo

2011-04-01

In wastewater treatment plants, the reject water from the sludge treatment processes typically contains high ammonium concentrations, which constitute a significant internal nitrogen load in the plant. Often, a separate nitrification reactor is used to treat the reject water before it is fed back into the plant. The nitrification reaction consumes alkalinity, which has to be replenished by dosing e.g. NaOH or Ca(OH)(2). In this study, we investigated the use of a two-compartment microbial fuel cell (MFC) to redistribute alkalinity from influent wastewater to support nitrification of reject water. In an MFC, alkalinity is consumed in the anode compartment and produced in the cathode compartment. We use this phenomenon and the fact that the influent wastewater flow is many times larger than the reject water flow to transfer alkalinity from the influent wastewater to the reject water. In a laboratory-scale system, ammonium oxidation of synthetic reject water passed through the cathode chamber of an MFC, increased from 73.8 ± 8.9 mgN/L under open-circuit conditions to 160.1 ± 4.8 mgN/L when a current of 1.96 ± 0.37 mA (15.1 mA/L total MFC liquid volume) was flowing through the MFC. These results demonstrated the positive effect of an MFC on ammonium oxidation of alkalinity-limited reject water. Copyright © 2011 Elsevier Ltd. All rights reserved.

Physical and virtual water transfers for regional water stress alleviation in China.

PubMed

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R; Guan, Dabo; Hubacek, Klaus

2015-01-27

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management.

47 CFR 76.1909 - Redistribution control of unencrypted digital terrestrial broadcast content.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Redistribution control of unencrypted digital... Redistribution control of unencrypted digital terrestrial broadcast content. (a) For the purposes of this section, the terms unencrypted digital terrestrial broadcast content, EIT, PMT, broadcast flag, covered...

Influences of sediment redistribution on sea-level changes along the U.S. Atlantic margin since the mid-Pliocene

NASA Astrophysics Data System (ADS)

Li, Q.; Ferrier, K.; Austermann, J.; Mitrovica, J. X.

2017-12-01

The Orangeburg Scarp is a paleo-shoreline formed along the southeastern U.S. Atlantic coast during the mid-Pliocene warm period (MPWP; 3.3 - 2.9 Ma). The MPWP is a time of interest because it is often cited as an analog for modern climate and thus an important target for understanding sea-level responses to climate change. The present Orangeburg Scarp exhibits 40-meter variations in elevation along its length, implying that it has been warped since its formation, which complicates efforts to infer global ice volume at the MPWP. Previous studies have shown that the effects of glacial isostatic adjustment (GIA) and dynamic topography (DT) on sea level can explain a significant fraction of the observed variability in elevation along the Orangeburg Scarp. Here we build on these studies by using a gravitationally self-consistent ice age sea-level model to compute the effects of sediment loading and unloading on paleo-shoreline elevation since the mid-Pliocene. To constrain the sediment loading history in this region, we present a new compilation of erosion and deposition rates along the U.S. Atlantic margin, from which we generate a range of sediment redistribution scenarios since the MPWP. We simultaneously drive the sea-level model with these sediment redistribution histories and existing ice and dynamic topography histories. Our results show that sediment loading and unloading is capable of warping the elevation of this paleo-shoreline by 20 meters since its formation, similar in magnitude to the contributions from GIA and DT over the same time period. These results demonstrate that sediment redistribution can induce significant perturbations in sea-level markers from the MPWP, and thus accounting for its influence will improve reconstructions of sea level and global ice volume during the MPWP and perhaps other periods of relative ice age warmth.

Mode-specific vibrational excitation and energy redistribution after ultrafast intramolecular electron transfer

NASA Astrophysics Data System (ADS)

Hogiu, S.; Werncke, W.; Pfeiffer, M.; Dreyer, J.; Elsaesser, T.

2000-07-01

Vibrational relaxation in the electronic ground state initiated by intramolecular back-electron transfer (b-ET) of betaine-30 (B-30) is studied by picosecond time-resolved anti-Stokes Raman spectroscopy. Measurements were carried out with B-30 dissolved in slowly as well as in rapidly relaxing solvents. We observed a risetime of the Raman band with the highest frequency near 1600 cm-1 which is close to the b-ET time τb-ET of B-30. For B-30 dissolved in propylene carbonate (τb-ET˜1 ps), the population of this mode exhibits a rise time of 1 ps whereas vibrational populations between 400 and 1400 cm-1 increase substantially slower. In contrast, in glycerol triacetin (τb-ET˜3.5 ps) and in ethanol (τb-ET˜6 ps) rise times of all modes are close to the respective b-ET times. Within the first few picoseconds, direct vibrational excitation through b-ET is favored for modes with the highest frequencies and high Franck-Condon factors. Later on, indirect channels of population due to vibrational energy redistribution (IVR) become effective. Thermal equilibrium populations of the Raman active modes are established within 10 to 15 ps after optical excitation.

7 CFR 247.24 - Recovery and redistribution of caseload and administrative funds.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Recovery and redistribution of caseload and...) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.24 Recovery and redistribution of caseload and administrative funds. (a) May FNS...

Redistribution on the thallium scan in myocardial sarcoidosis: concise communication

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

Makler, P.T.; Lavine, S.J.; Denenberg, B.S.

1981-05-01

Resting and redistribution thallium studies were performed in four young patients with sarcoidosis to evaluate the possibility of myocardial involvement. In each case the resting scan showed marked defects that resolved on the redistribution studies. In a different patient population, these results would have implied significant coronary artery disease.

45 CFR 98.64 - Reallotment and redistribution of funds.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false Reallotment and redistribution of funds. 98.64 Section 98.64 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Financial Management § 98.64 Reallotment and redistribution of funds. (a) According to the...

45 CFR 98.64 - Reallotment and redistribution of funds.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Reallotment and redistribution of funds. 98.64 Section 98.64 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Financial Management § 98.64 Reallotment and redistribution of funds. (a) According to the...

45 CFR 98.64 - Reallotment and redistribution of funds.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 1 2013-10-01 2013-10-01 false Reallotment and redistribution of funds. 98.64 Section 98.64 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Financial Management § 98.64 Reallotment and redistribution of funds. (a) According to the...

Process-oriented modelling to identify main drivers of erosion-induced carbon fluxes

NASA Astrophysics Data System (ADS)

Wilken, Florian; Sommer, Michael; Van Oost, Kristof; Bens, Oliver; Fiener, Peter

2017-05-01

Coupled modelling of soil erosion, carbon redistribution, and turnover has received great attention over the last decades due to large uncertainties regarding erosion-induced carbon fluxes. For a process-oriented representation of event dynamics, coupled soil-carbon erosion models have been developed. However, there are currently few models that represent tillage erosion, preferential water erosion, and transport of different carbon fractions (e.g. mineral bound carbon, carbon encapsulated by soil aggregates). We couple a process-oriented multi-class sediment transport model with a carbon turnover model (MCST-C) to identify relevant redistribution processes for carbon dynamics. The model is applied for two arable catchments (3.7 and 7.8 ha) located in the Tertiary Hills about 40 km north of Munich, Germany. Our findings indicate the following: (i) redistribution by tillage has a large effect on erosion-induced vertical carbon fluxes and has a large carbon sequestration potential; (ii) water erosion has a minor effect on vertical fluxes, but episodic soil organic carbon (SOC) delivery controls the long-term erosion-induced carbon balance; (iii) delivered sediments are highly enriched in SOC compared to the parent soil, and sediment delivery is driven by event size and catchment connectivity; and (iv) soil aggregation enhances SOC deposition due to the transformation of highly mobile carbon-rich fine primary particles into rather immobile soil aggregates.

The Ultimate Spitzer Phase Curve Survey

NASA Astrophysics Data System (ADS)

Stevenson, Kevin; Bean, Jacob; Deming, Drake; Desert, Jean-Michel; Feng, Y. Katherina; Fortney, Jonathan; Kataria, Tiffany; Kempton, Eliza; Lewis, Nikole; Line, Michael; Morley, Caroline; Rauscher, Emily; Showman, Adam

2016-08-01

Exoplanet phase curves are sure to be one of the main enduring legacies of Spitzer. They provide a wealth of information about exoplanet atmospheres, including longitudinal constraints on atmospheric composition, thermal structure, and energy transport, that will continue to open new doors of scientific inquiry and propel future investigations for years to come. The measured heat redistribution efficiency (or ability to transport energy from a planet's highly-irradiated dayside to its eternally-dark nightside) shows considerable variation between exoplanets. Theoretical models predict a correlation between heat redistribution efficiency and planet temperature; however, the latest results are inconsistent with current predictions. Instead, a new potential trend is emerging, one that connects heat redistribution efficiency with planet rotation rate. We will test this hypothesis by performing Spitzer phase curve observations of seven exoplanets with physical properties that span the parameter space. We have identified high-contrast targets with short orbital periods around bright host stars to ensure the observations reveal robust phase curve results. Spitzer is uniquely suited for this program because we can achieve our primary goals using broadband photometry. Part of the phase curve legacy will be to combine our archived Spitzer data with transmission and dayside emission spectra from HST and JWST. Adding energy transport and cloud coverage constraints to the measured dayside abundances and thermal profiles will yield a fundamental understanding of these exoplanets' atmospheres that can be leveraged into new avenues of investigation.

Electrical Resistivity Tomography Reveals Upward Redistribution of Soil-Water by Coyote Brush in a Shrub-Grassland Ecotone

NASA Astrophysics Data System (ADS)

Manning, J. E.; Schulz, M. S.; Lambrecht, D. S.

2016-12-01

Species imbalance within many California plant assemblages may arise due to more intense wildfires as well as climate warming. Given this, coyote brush (Baccharis pilularis DC), a native evergreen shrub known as a ready colonizer of disturbed soil, may become more dominant. While prolonged spring soil moisture is required for seedling establishment, 1+ year-old coyote brush can withstand low soil water potentials (-1.2 MPa). Beyond this, little is known about its soil-water dynamics. Hydraulic redistribution of water within the soil profile by plant roots has been established in numerous species in the past 20 years. Recent quantification of the water quantity re-distributed by root systems are beginning to provide detail that could inform ET, weathering, and carbon cycling models. Electrical resistivity tomography (ERT) has been used to study soil hydraulics in natural as well as cropland settings. This study is the first known to use ERT to investigate hydraulic redistribution in coyote brush. One mid-size shrub surrounded by open grassland was selected at the study site, located on a coastal marine terrace west of Santa Cruz, CA. The soil profile, previously characterized with ERT and auger-based soil-water sampling, includes a clay-rich B horizon and is texturally non-uniform due to bioturbation to 0.6 meter. The 12-m ERT survey transect had 48 semi-permanent electrodes, with the 4-m wide shrub canopy at probes 16 to 32. Five repeats of evening and morning surveys were conducted. Heterogeneous texture and severe soil drying necessitated qualitative comparison across time. Overnight resistivity changes using differences plots of the modelled data revealed increased moisture beneath the shrub canopy during the night. Areas beyond the canopy—presumably outside the root zone—experienced variable overnight changes, with moisture increasing in the clay-rich horizon. Preliminary analysis suggests that coyote brush roots redistribute water upward within the soil profile.

Simulating the Dependence of Aspen on Redistributed Snow

NASA Astrophysics Data System (ADS)

Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Winstral, A. H.

2013-12-01

In mountainous regions across the western USA, the distribution of aspen (Populus tremuloides) is often directly related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho provides a unique opportunity to study the relationship between aspen and redistributed snow. Within the RCEW, the total amount of precipitation has not changed in the past 50 years, but there are sharp declines in the percentage of the precipitation falling as snow. As shifts in the distribution of available moisture continue, future trends in aspen net primary productivity (NPP) remain uncertain. In order to assess the importance of snowdrift subsidies, NPP of three aspen stands was simulated at sites spanning elevational and precipitation gradients using the biogeochemical process model BIOME-BGC. At the aspen site experiencing the driest climate and lowest amount of precipitation from snow, approximately 400 mm of total precipitation was measured from November to March of 2008. However, peak measured snow water equivalent (SWE) held in drifts directly upslope of this stand was approximately 2100 mm, 5 times more moisture than the uniform winter precipitation layer initially assumed by BIOME-BGC. BIOME-BGC simulations in dry years forced by adjusted precipitation data resulted in NPP values approximately 30% higher than simulations assuming a uniform precipitation layer. Using BIOME-BGC and climate data from 1985-2011, the relationship between simulated NPP and measured basal area increments (BAI) improved after accounting for redistributed snow, indicating increased simulation representation. In addition to improved simulation capabilities, soil moisture data, diurnal branch water potential, and stomatal conductance observations at each site detail the use of soil moisture in the rooting zone and the onset of drought stress occurring in stands located along a precipitation phase gradient. These results further emphasize the importance of redistributed snow in heterogeneous landscapes along with the need to account for temporal shifts in water resource availability when assessing ecosystem vulnerability to climate change.

Soil Organic Carbon Redistribution by Water Erosion – The Role of CO2 Emissions for the Carbon Budget

PubMed Central

Wang, Xiang; Cammeraat, Erik L. H.; Romeijn, Paul; Kalbitz, Karsten

2014-01-01

A better process understanding of how water erosion influences the redistribution of soil organic carbon (SOC) is sorely needed to unravel the role of soil erosion for the carbon (C) budget from local to global scales. The main objective of this study was to determine SOC redistribution and the complete C budget of a loess soil affected by water erosion. We measured fluxes of SOC, dissolved organic C (DOC) and CO2 in a pseudo-replicated rainfall-simulation experiment. We characterized different C fractions in soils and redistributed sediments using density fractionation and determined C enrichment ratios (CER) in the transported sediments. Erosion, transport and subsequent deposition resulted in significantly higher CER of the sediments exported ranging between 1.3 and 4.0. In the exported sediments, C contents (mg per g soil) of particulate organic C (POC, C not bound to soil minerals) and mineral-associated organic C (MOC) were both significantly higher than those of non-eroded soils indicating that water erosion resulted in losses of C-enriched material both in forms of POC and MOC. The averaged SOC fluxes as particles (4.7 g C m−2 yr−1) were 18 times larger than DOC fluxes. Cumulative emission of soil CO2 slightly decreased at the erosion zone while increased by 56% and 27% at the transport and depositional zone, respectively, in comparison to non-eroded soil. Overall, CO2 emission is the predominant form of C loss contributing to about 90.5% of total erosion-induced C losses in our 4-month experiment, which were equal to 18 g C m−2. Nevertheless, only 1.5% of the total redistributed C was mineralized to CO2 indicating a large stabilization after deposition. Our study also underlines the importance of C losses by particles and as DOC for understanding the effects of water erosion on the C balance at the interface of terrestrial and aquatic ecosystems. PMID:24802350

Increased T-helper 17 cell differentiation mediated by exosome-mediated microRNA-451 redistribution in gastric cancer infiltrated T cells.

PubMed

Liu, Feng; Bu, Zhouyan; Zhao, Feng; Xiao, Daping

2018-01-01

MicroRNA (miR)-451 is a cell metabolism-related miRNA that can mediate cell energy-consuming models by several targets. As miR-451 can promote mechanistic target of rapamycin (mTOR) activity, and increased mTOR activity is related to increased differentiation of T-helper 17 (Th17) cells, we sought to investigate whether miR-451 can redistribute from cancer cells to infiltrated T cells and enhance the distribution of Th17 cells through mTOR. Real-time PCR was used for detecting expression of miR-451 in gastric cancer, tumor infiltrated T cells and exosomes, and distribution of Th17 was evaluated by both flow cytometry and immunohistochemistry (IHC). Immunofluorescence staining was used in monitoring the exosome-enveloped miR-451 from cancer cells to T cells with different treatments, and signaling pathway change was analyzed by western blot. miR-451 decreased significantly in gastric cancer (GC) tissues but increased in infiltrated T cells and exosomes; tumor miR-451 was negatively related to infiltrated T cells and exosome miR-451. Exosome miR-451 can not only serve as an indicator for poor prognosis of post-operation GC patients but is also related to increased Th17 distribution in gastric cancer. miR-451 can redistribute from cancer cells to T cells with low glucose treatment. Decreased 5' AMP-activated protein kinase (AMPK) and increased mTOR activity was investigated in miR-451 redistributed T cells and the Th17 polarized differentiation of these T cells were also increased. Exosome miR-451 derived from tumor tissues can serve as an indicator for poor prognosis and redistribution of miR-451 from cancer cells to infiltrated T cells in low glucose treatment can enhance Th17 differentiation by enhancing mTOR activity. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Modeling Edge Effects of Tillage Erosion

USDA-ARS?s Scientific Manuscript database

Tillage erosion has been recognized as an important factor in redistribution of soil over time and in the development of morphological changes within agricultural fields. Field borders, fences, and vegetated strips that interrupt soil fluxes lead to the creation topographic discontinuities or lynche...

Role of a continuous MHD dynamo in the formation of 3D equilibria in fusion plasmas

NASA Astrophysics Data System (ADS)

Piovesan, P.; Bonfiglio, D.; Cianciosa, M.; Luce, T. C.; Taylor, N. Z.; Terranova, D.; Turco, F.; Wilcox, R. S.; Wingen, A.; Cappello, S.; Chrystal, C.; Escande, D. F.; Holcomb, C. T.; Marrelli, L.; Paz-Soldan, C.; Piron, L.; Predebon, I.; Zaniol, B.; DIII-D, The; RFX-Mod Teams

2017-07-01

Stationary 3D equilibria can form in fusion plasmas via saturation of magnetohydrodynamic (MHD) instabilities or stimulated by external 3D fields. In these cases the current profile is anomalously broad due to magnetic flux pumping produced by the MHD modes. Flux pumping plays an important role in hybrid tokamak plasmas, maintaining the minimum safety factor above unity and thus removing sawteeth. It also enables steady-state hybrid operation, by redistributing non-inductive current driven near the center by electron cyclotron waves. A validated flux pumping model is not yet available, but it would be necessary to extrapolate hybrid operation to future devices. In this work flux pumping physics is investigated for helical core equilibria stimulated by external 3D fields in DIII-D hybrid plasmas. We show that flux pumping can be produced in a continuous way by an MHD dynamo emf. The same effect maintains helical equilibria in reversed-field pinch (RFP) plasmas. The effective MHD dynamo loop voltage is calculated for experimental 3D equilibrium reconstructions, by balancing Ohm’s law over helical flux surfaces, and is consistent with the expected current redistribution. Similar results are also obtained with more sophisticated nonlinear MHD simulations. The same modelling approach is applied to helical RFP states forming spontaneously in RFX-mod as the plasma current is raised above 0.8-1 MA. This comparison allows to identify the underlying physics common to tokamak and RFP: a helical core displacement modulates parallel current density along flux tubes, which requires a helical electrostatic potential to build up, giving rise to a helical MHD dynamo flow.

Role of a continuous MHD dynamo in the formation of 3D equilibria in fusion plasmas

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

Piovesan, P.; Bonfiglio, D.; Cianciosa, M.

Stationary 3D equilibria can form in fusion plasmas via saturation of magnetohydrodynamic (MHD) instabilities or stimulated by external 3D fields. In these cases the current profile is anomalously broad due to magnetic flux pumping produced by the MHD modes. Flux pumping plays an important role in hybrid tokamak plasmas, maintaining the minimum safety factor above unity and thus removing sawteeth. It also enables steady-state hybrid operation, by redistributing non-inductive current driven near the center by electron cyclotron waves. A validated flux pumping model is not yet available, but it would be necessary to extrapolate hybrid operation to future devices. Inmore » this work flux pumping physics is investigated for helical core equilibria stimulated by external 3D fields in DIII-D hybrid plasmas. We show that flux pumping can be produced in a continuous way by an MHD dynamo emf. The same effect maintains helical equilibria in reversed-field pinch (RFP) plasmas. The effective MHD dynamo loop voltage is calculated for experimental 3D equilibrium reconstructions, by balancing Ohm’s law over helical flux surfaces, and is consistent with the expected current redistribution. Similar results are also obtained with more sophisticated nonlinear MHD simulations. The same modelling approach is applied to helical RFP states forming spontaneously in RFX-mod as the plasma current is raised above 0.8–1 MA. This comparison allows to identify the underlying physics common to tokamak and RFP: a helical core displacement modulates parallel current density along flux tubes, which requires a helical electrostatic potential to build up, giving rise to a helical MHD dynamo flow.« less

Role of a continuous MHD dynamo in the formation of 3D equilibria in fusion plasmas

DOE PAGES

Piovesan, P.; Bonfiglio, D.; Cianciosa, M.; ...

2017-04-28

Stationary 3D equilibria can form in fusion plasmas via saturation of magnetohydrodynamic (MHD) instabilities or stimulated by external 3D fields. In these cases the current profile is anomalously broad due to magnetic flux pumping produced by the MHD modes. Flux pumping plays an important role in hybrid tokamak plasmas, maintaining the minimum safety factor above unity and thus removing sawteeth. It also enables steady-state hybrid operation, by redistributing non-inductive current driven near the center by electron cyclotron waves. A validated flux pumping model is not yet available, but it would be necessary to extrapolate hybrid operation to future devices. Inmore » this work flux pumping physics is investigated for helical core equilibria stimulated by external 3D fields in DIII-D hybrid plasmas. We show that flux pumping can be produced in a continuous way by an MHD dynamo emf. The same effect maintains helical equilibria in reversed-field pinch (RFP) plasmas. The effective MHD dynamo loop voltage is calculated for experimental 3D equilibrium reconstructions, by balancing Ohm’s law over helical flux surfaces, and is consistent with the expected current redistribution. Similar results are also obtained with more sophisticated nonlinear MHD simulations. The same modelling approach is applied to helical RFP states forming spontaneously in RFX-mod as the plasma current is raised above 0.8–1 MA. This comparison allows to identify the underlying physics common to tokamak and RFP: a helical core displacement modulates parallel current density along flux tubes, which requires a helical electrostatic potential to build up, giving rise to a helical MHD dynamo flow.« less

Soil quality and water redistribution influences on plant production over low hillslopes on reclaimed mined land

USDA-ARS?s Scientific Manuscript database

A basic part of soils’ delivery of ecosystem services is the interaction between plant growth response to soil quality (SQ) factors at point scale and water redistribution effects at hillslope scale. To study the influence of SQ-indicator properties and water redistribution, we examined hillslope pr...

7 CFR 247.24 - Recovery and redistribution of caseload and administrative funds.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 4 2013-01-01 2013-01-01 false Recovery and redistribution of caseload and... FOOD PROGRAM § 247.24 Recovery and redistribution of caseload and administrative funds. (a) May FNS... agency must use 95 percent of its original caseload allocation to be eligible for additional caseload...

7 CFR 247.24 - Recovery and redistribution of caseload and administrative funds.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 4 2014-01-01 2014-01-01 false Recovery and redistribution of caseload and... FOOD PROGRAM § 247.24 Recovery and redistribution of caseload and administrative funds. (a) May FNS... agency must use 95 percent of its original caseload allocation to be eligible for additional caseload...

7 CFR 247.24 - Recovery and redistribution of caseload and administrative funds.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 4 2012-01-01 2012-01-01 false Recovery and redistribution of caseload and... FOOD PROGRAM § 247.24 Recovery and redistribution of caseload and administrative funds. (a) May FNS... agency must use 95 percent of its original caseload allocation to be eligible for additional caseload...

Development Planning and Population Growth and Redistribution in the Republic of Iraq.

ERIC Educational Resources Information Center

El Attar, M. E.; Salman, A. D.

Utilizing the 1947, 1957, and l965 census data and the 1970 preliminary population count, the relationship between population growth and redistribution and development planning in Iraq was examined. Trends in rural-urban population growth, migration, and population redistribution were examined as they pertained to the socioeconomic development…

Exploiting the flexibility of a family of models for taxation and redistribution

NASA Astrophysics Data System (ADS)

Bertotti, M. L.; Modanese, G.

2012-08-01

We discuss a family of models expressed by nonlinear differential equation systems describing closed market societies in the presence of taxation and redistribution. We focus in particular on three example models obtained in correspondence to different parameter choices. We analyse the influence of the various choices on the long time shape of the income distribution. Several simulations suggest that behavioral heterogeneity among the individuals plays a definite role in the formation of fat tails of the asymptotic stationary distributions. This is in agreement with results found with different approaches and techniques. We also show that an excellent fit for the computational outputs of our models is provided by the κ-generalized distribution introduced by Kaniadakis in [Physica A 296, 405 (2001)].

Overload cascading failure on complex networks with heterogeneous load redistribution

NASA Astrophysics Data System (ADS)

Hou, Yueyi; Xing, Xiaoyun; Li, Menghui; Zeng, An; Wang, Yougui

2017-09-01

Many real systems including the Internet, power-grid and financial networks experience rare but large overload cascading failures triggered by small initial shocks. Many models on complex networks have been developed to investigate this phenomenon. Most of these models are based on the load redistribution process and assume that the load on a failed node shifts to nearby nodes in the networks either evenly or according to the load distribution rule before the cascade. Inspired by the fact that real power-grid tends to place the excess load on the nodes with high remaining capacities, we study a heterogeneous load redistribution mechanism in a simplified sandpile model in this paper. We find that weak heterogeneity in load redistribution can effectively mitigate the cascade while strong heterogeneity in load redistribution may even enlarge the size of the final failure. With a parameter θ to control the degree of the redistribution heterogeneity, we identify a rather robust optimal θ∗ = 1. Finally, we find that θ∗ tends to shift to a larger value if the initial sand distribution is homogeneous.

Incorporating convection into one-dimensional solute redistribution during crystal growth from the melt I. The steady-state solution

NASA Astrophysics Data System (ADS)

Yen, C. T.; Tiller, W. A.

1992-03-01

A one-dimensional mathematical analysis is made of the redistribution of solute which occurs during crystal growth from a convected melt. In this analysis, the important contribution from lateral melt convection to one-dimensional solute redistribution analysis is taken into consideration via an annihilation/creation term in the one-dimensional solute transport equation. Calculations of solute redistribution under steady-state conditions have been carried out analytically. It is found that this new solute redistribution model overcomes several weaknesses that occur when applying the Burton, Prim and Slichter solute segregation equation (1953) in real melt growth situations. It is also found that, with this correction, the diffusion coefficients for solute's in liquid silicon are now found to be in the same range as other liquid metal diffusion coefficients.

Potential biases in evapotranspiration estimates from Earth system models due to spatial heterogeneity and lateral moisture redistribution

NASA Astrophysics Data System (ADS)

Rouholahnejad, E.; Kirchner, J. W.

2016-12-01

Evapotranspiration (ET) is a key process in land-climate interactions and affects the dynamics of the atmosphere at local and regional scales. In estimating ET, most earth system models average over considerable sub-grid heterogeneity in land surface properties, precipitation (P), and potential evapotranspiration (PET). This spatial averaging could potentially bias ET estimates, due to the nonlinearities in the underlying relationships. In addition, most earth system models ignore lateral redistribution of water within and between grid cells, which could potentially alter both local and regional ET. Here we present a first attempt to quantify the effects of spatial heterogeneity and lateral redistribution on grid-cell-averaged ET as seen from the atmosphere over heterogeneous landscapes. Using a Budyko framework to express ET as a function of P and PET, we quantify how sub-grid heterogeneity affects average ET at the scale of typical earth system model grid cells. We show that averaging over sub-grid heterogeneity in P and PET, as typical earth system models do, leads to overestimates of average ET. We use a similar approach to quantify how lateral redistribution of water could affect average ET, as seen from the atmosphere. We show that where the aridity index P/PET increases with altitude, gravitationally driven lateral redistribution will increase average ET, implying that models that neglect lateral moisture redistribution will underestimate average ET. In contrast, where the aridity index P/PET decreases with altitude, gravitationally driven lateral redistribution will decrease average ET. This approach yields a simple conceptual framework and mathematical expressions for determining whether, and how much, spatial heterogeneity and lateral redistribution can affect regional ET fluxes as seen from the atmosphere. This analysis provides the basis for quantifying heterogeneity and redistribution effects on ET at regional and continental scales, which will be the focus of future work.

Redistributive effects in public health care financing.

PubMed

Honekamp, Ivonne; Possenriede, Daniel

2008-11-01

This article focuses on the redistributive effects of different measures to finance public health insurance. We analyse the implications of different financing options for public health insurance on the redistribution of income from good to bad health risks and from high-income to low-income individuals. The financing options considered are either income-related (namely income taxes, payroll taxes, and indirect taxes), health-related (co-insurance, deductibles, and no-claim), or neither (flat fee). We show that governments who treat access to health care as a basic right for everyone should consider redistributive effects when reforming health care financing.

Periodical climate variations and their impact on Earth rotation for the last 800Kyr

NASA Astrophysics Data System (ADS)

Chapanov, Yavor; Gambis, Daniel

2010-05-01

The Earth rotation variations are highly affected by climatic variations associated with the glacial cycles in the late Pleistocene. The processes of glaciation, followed by ice melting, are connected with significant changes of the mean sea level. These processes redistribute great amount of water masses between oceans and ice sheets, which lead to changes of the axial moment of inertia and corresponding variations of the Universal Time UT1 and Length of Day LOD, according to the law of angular momentum conservation. The climatic variations for the last 800Kyr are analyzed by means of time series of temperature changes, determined by deuterium data from Antarctica ice core. Reconstructed glacial sea level variations for the last 380Kyr, determined by the sediments from the Red sea, are used, too. Common periodicities of the temperature and mean sea level variations are determined. Time series of the long-periodical UT1 and LOD oscillations for the last 380Kyr and 800Kyr are reconstructed by means of empirical hydrological model of global water redistribution between the ocean and ice sheets during the last glacial events.

Transmembrane ion distribution during recovery from freezing in the woolly bear caterpillar Pyrrharctia isabella (Lepidoptera: Arctiidae).

PubMed

Boardman, Leigh; Terblanche, John S; Sinclair, Brent J

2011-08-01

During extracellular freezing, solutes in the haemolymph are concentrated, resulting in osmotic dehydration of the cells, which must be reversed upon thawing. Here, we used freeze tolerant Pyrrharctia isabella (Lepidoptera: Arctiidae) larvae to examine the processes of ion redistribution after thawing. To investigate the effect of the intensity of cold exposure on ion redistribution after thawing, we exposed caterpillars to -14°C, -20°C or -30°C for 35h. To investigate the effect of duration of cold exposure on ion redistribution after thawing, we exposed the caterpillars to -14°C for up to 6 weeks while sampling several time points. The concentrations of Na(+), K(+), Mg(2+) and Ca(2+) were measured after thawing in the haemolymph, fat body, muscle, midgut tissue and hindgut tissue. Being frozen for long durations (>3 weeks) or at low temperatures (-30°C) both result in 100% mortality, although different ions and tissues appear to be affected by each treatment. Both water distribution and ion content changes were detected after thawing, with the largest effects seen in the fat body and midgut tissue. Magnesium homeostasis appears to be vital for post-freeze survival in these larvae. The movement of ions during thawing lagged behind the movement of water, and ion homeostasis was not restored within the same time frame as water homeostasis. Failure to regain ion homeostasis after thawing is therefore implicated in mortality of freeze tolerant insects. Copyright © 2011 Elsevier Ltd. All rights reserved.

Regulation of Primary Metabolism in Response to Low Oxygen Availability as Revealed by Carbon and Nitrogen Isotope Redistribution.

PubMed

António, Carla; Päpke, Carola; Rocha, Marcio; Diab, Houssein; Limami, Anis M; Obata, Toshihiro; Fernie, Alisdair R; van Dongen, Joost T

2016-01-01

Based on enzyme activity assays and metabolic responses to waterlogging of the legume Lotus japonicus, it was previously suggested that, during hypoxia, the tricarboxylic acid cycle switches to a noncyclic operation mode. Hypotheses were postulated to explain the alternative metabolic pathways involved, but as yet, a direct analysis of the relative redistribution of label through the corresponding pathways was not made. Here, we describe the use of stable isotope-labeling experiments for studying metabolism under hypoxia using wild-type roots of the crop legume soybean (Glycine max). [(13)C]Pyruvate labeling was performed to compare metabolism through the tricarboxylic acid cycle, fermentation, alanine metabolism, and the γ-aminobutyric acid shunt, while [(13)C]glutamate and [(15)N]ammonium labeling were performed to address the metabolism via glutamate to succinate. Following these labelings, the time course for the redistribution of the (13)C/(15)N label throughout the metabolic network was evaluated with gas chromatography-time of flight-mass spectrometry. Our combined labeling data suggest the inhibition of the tricarboxylic acid cycle enzyme succinate dehydrogenase, also known as complex II of the mitochondrial electron transport chain, providing support for the bifurcation of the cycle and the down-regulation of the rate of respiration measured during hypoxic stress. Moreover, up-regulation of the γ-aminobutyric acid shunt and alanine metabolism explained the accumulation of succinate and alanine during hypoxia. © 2016 American Society of Plant Biologists. All Rights Reserved.

Neuron matters: electric activation of neuronal tissue is dependent on the interaction between the neuron and the electric field.

PubMed

Ye, Hui; Steiger, Amanda

2015-08-12

In laboratory research and clinical practice, externally-applied electric fields have been widely used to control neuronal activity. It is generally accepted that neuronal excitability is controlled by electric current that depolarizes or hyperpolarizes the excitable cell membrane. What determines the amount of polarization? Research on the mechanisms of electric stimulation focus on the optimal control of the field properties (frequency, amplitude, and direction of the electric currents) to improve stimulation outcomes. Emerging evidence from modeling and experimental studies support the existence of interactions between the targeted neurons and the externally-applied electric fields. With cell-field interaction, we suggest a two-way process. When a neuron is positioned inside an electric field, the electric field will induce a change in the resting membrane potential by superimposing an electrically-induced transmembrane potential (ITP). At the same time, the electric field can be perturbed and re-distributed by the cell. This cell-field interaction may play a significant role in the overall effects of stimulation. The redistributed field can cause secondary effects to neighboring cells by altering their geometrical pattern and amount of membrane polarization. Neurons excited by the externally-applied electric field can also affect neighboring cells by ephaptic interaction. Both aspects of the cell-field interaction depend on the biophysical properties of the neuronal tissue, including geometric (i.e., size, shape, orientation to the field) and electric (i.e., conductivity and dielectricity) attributes of the cells. The biophysical basis of the cell-field interaction can be explained by the electromagnetism theory. Further experimental and simulation studies on electric stimulation of neuronal tissue should consider the prospect of a cell-field interaction, and a better understanding of tissue inhomogeneity and anisotropy is needed to fully appreciate the neural basis of cell-field interaction as well as the biological effects of electric stimulation.

Modeling and characterization of supercapacitors for wireless sensor network applications

NASA Astrophysics Data System (ADS)

Zhang, Ying; Yang, Hengzhao

A simple circuit model is developed to describe supercapacitor behavior, which uses two resistor-capacitor branches with different time constants to characterize the charging and redistribution processes, and a variable leakage resistance to characterize the self-discharge process. The parameter values of a supercapacitor can be determined by a charging-redistribution experiment and a self-discharge experiment. The modeling and characterization procedures are illustrated using a 22F supercapacitor. The accuracy of the model is compared with that of other models often used in power electronics applications. The results show that the proposed model has better accuracy in characterizing the self-discharge process while maintaining similar performance as other models during charging and redistribution processes. Additionally, the proposed model is evaluated in a simplified energy storage system for self-powered wireless sensors. The model performance is compared with that of a commonly used energy recursive equation (ERE) model. The results demonstrate that the proposed model can predict the evolution profile of voltage across the supercapacitor more accurately than the ERE model, and therefore provides a better alternative for supporting research on storage system design and power management for wireless sensor networks.

Evaluating clustering methods within the Artificial Ecosystem Algorithm and their application to bike redistribution in London.

PubMed

Adham, Manal T; Bentley, Peter J

2016-08-01

This paper proposes and evaluates a solution to the truck redistribution problem prominent in London's Santander Cycle scheme. Due to the complexity of this NP-hard combinatorial optimisation problem, no efficient optimisation techniques are known to solve the problem exactly. This motivates our use of the heuristic Artificial Ecosystem Algorithm (AEA) to find good solutions in a reasonable amount of time. The AEA is designed to take advantage of highly distributed computer architectures and adapt to changing problems. In the AEA a problem is first decomposed into its relative sub-components; they then evolve solution building blocks that fit together to form a single optimal solution. Three variants of the AEA centred on evaluating clustering methods are presented: the baseline AEA, the community-based AEA which groups stations according to journey flows, and the Adaptive AEA which actively modifies clusters to cater for changes in demand. We applied these AEA variants to the redistribution problem prominent in bike share schemes (BSS). The AEA variants are empirically evaluated using historical data from Santander Cycles to validate the proposed approach and prove its potential effectiveness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Behaviors of heavy metals (Cd, Cu, Ni, Pb and Zn) in soil amended with composts.

PubMed

Gusiatin, Zygmunt Mariusz; Kulikowska, Dorota

2016-09-01

This study investigated how amendment with sewage sludge compost of different maturation times (3, 6, 12 months) affected metal (Cd, Cu, Ni, Pb, Zn) bioavailability, fractionation and redistribution in highly contaminated sandy clay soil. Metal transformations during long-term soil stabilization (35 months) were determined. In the contaminated soil, Cd, Ni and Zn were predominately in the exchangeable and reducible fractions, Pb in the reducible fraction and Cu in the reducible, exchangeable and oxidizable fractions. All composts decreased the bioavailability of Cd, Ni and Zn for up to 24 months, which indicates that cyclic amendment with compost is necessary. The bioavailability of Pb and Cu was not affected by compost amendment. Based on the reduced partition index (IR), metal stability in amended soil after 35 months of stabilization was in the following order: Cu > Ni = Pb > Zn > Cd. All composts were more effective in decreasing Cd, Ni and Zn bioavailability than in redistributing the metals, and increasing Cu redistribution more than that of Pb. Thus, sewage sludge compost of as little as 3 months maturation can be used for cyclic amendment of multi-metal-contaminated soil.

Redistribution kinetics of Ga and Al substitutions in yttrium iron garnet

NASA Astrophysics Data System (ADS)

Röschmann, P.

1980-01-01

Results are presented for the octahedral-tetrahedral site redistribution rate of Ga or Al and Fe in YIG in the temperature range 773 to 1523 K. The activation energy for the cation transfer decreases with increasing the oxygen vacancy concentration by annealing. A screening model describes qualitatively the effects of enhanced cation redistribution.

Hydraulic redistribution in a Douglas-fir forest: lessons from system manipulations.

Treesearch

J. Renée Brooks; Frederick C. Meinzer; Jeffery M. Warren; Jean-Christophe Domec; Rob Coulombe

2006-01-01

Hydraulic redistribution (HR) occurs in many ecosystems; however, key questions remain about its consequences at the ecosystem level. The objectives of the present study were to quantify seasonal variation in HR and its driving force, and to manipulate the soil-root system to elucidate physiological components controlling HR and utilization of redistributed water. In...

Redistributing Wealth to Families: The Advantages of the MYRIADE Model

ERIC Educational Resources Information Center

Legendre, Francois; Lorgnet, Jean-Paul; Thibault, Florence

2005-01-01

This study aims to shed light on the main characteristics of the French system for redistributing wealth to families through tax revenues and social transfers. For the purposes of this exercise, the authors used the MYRIADE microsimulation model, which covers most of the redistribution system, though it is limited to monetary flows such as family…

Contaminant back-diffusion from low-permeability layers as affected by groundwater velocity: A laboratory investigation by box model and image analysis.

PubMed

Tatti, Fabio; Papini, Marco Petrangeli; Sappa, Giuseppe; Raboni, Massimo; Arjmand, Firoozeh; Viotti, Paolo

2018-05-01

Low-permeability lenses represent potential sources of long-term release when filled from contaminant solute through direct contact with dissolved plumes. The redistribution of contaminant from low to high permeability aquifer zones (Back-Diffusion) was studied. Redistribution causes a long plume tail, commonly regarded as one of the main obstacles to effective groundwater remediation. Laboratory tests were performed to reproduce the redistribution process and to investigate the effect of pumping water on the remediation time of these contaminated low-permeability lenses. The test section used is representative of clay/silt lenses (k≈1∗10 -10 m/s/k≈1∗10 -7 m/s) in a sand aquifer (k≈1∗10 -3 m/s). Hence, an image analysis procedure was used to estimate the diffusive flux of contaminant released by these low-permeability zones. The proposed technique was validated performing a mass balance of a lens saturated by a known quantity of tracer. For each test, performed using a different groundwater velocity, the diffusive fluxes of contaminant released by lenses were compared and the remediation times of the low-permeability zones calculated. For each lens, the obtained remediation timeframes were used to define an analytical relation vs groundwater velocity and the coefficients of these relations were matched to grain size of the low-permeability lenses. Results show that an increase of the velocity field is not useful to diminish the total depletion times as the process mainly diffusive. This is significant when the remediation approach relies on pumping technology. Copyright © 2017 Elsevier B.V. All rights reserved.

Adaptive finite-volume WENO schemes on dynamically redistributed grids for compressible Euler equations

NASA Astrophysics Data System (ADS)

Pathak, Harshavardhana S.; Shukla, Ratnesh K.

2016-08-01

A high-order adaptive finite-volume method is presented for simulating inviscid compressible flows on time-dependent redistributed grids. The method achieves dynamic adaptation through a combination of time-dependent mesh node clustering in regions characterized by strong solution gradients and an optimal selection of the order of accuracy and the associated reconstruction stencil in a conservative finite-volume framework. This combined approach maximizes spatial resolution in discontinuous regions that require low-order approximations for oscillation-free shock capturing. Over smooth regions, high-order discretization through finite-volume WENO schemes minimizes numerical dissipation and provides excellent resolution of intricate flow features. The method including the moving mesh equations and the compressible flow solver is formulated entirely on a transformed time-independent computational domain discretized using a simple uniform Cartesian mesh. Approximations for the metric terms that enforce discrete geometric conservation law while preserving the fourth-order accuracy of the two-point Gaussian quadrature rule are developed. Spurious Cartesian grid induced shock instabilities such as carbuncles that feature in a local one-dimensional contact capturing treatment along the cell face normals are effectively eliminated through upwind flux calculation using a rotated Hartex-Lax-van Leer contact resolving (HLLC) approximate Riemann solver for the Euler equations in generalized coordinates. Numerical experiments with the fifth and ninth-order WENO reconstructions at the two-point Gaussian quadrature nodes, over a range of challenging test cases, indicate that the redistributed mesh effectively adapts to the dynamic flow gradients thereby improving the solution accuracy substantially even when the initial starting mesh is non-adaptive. The high adaptivity combined with the fifth and especially the ninth-order WENO reconstruction allows remarkably sharp capture of discontinuous propagating shocks with simultaneous resolution of smooth yet complex small scale unsteady flow features to an exceptional detail.

[A study on training method for increasing adaptability to blood redistribution in human].

PubMed

Wu, Bin; You, Guang-xing; Wu, Ping; Xue, Yue-ying; Liu, Xing-hua; Su, Shuang-ning

2003-01-01

To verify validity of the increase in adaptability of blood redistribution in human body with repeated body position change training and to find preferable training method for increasing astronaut's adaptability of blood redistribution. Twelve subjects were randomly divided into group A and B. Six subjects in each group were trained with mode A and B repeated position change (9 times in 11 d) respectively. Their head-down tilt (HDT -30 degrees/30 min) tolerance and orthostatic tolerance were determined before and after training to verify training effects. 1) Two kinds of repeated body position change training modes increased all subjects' HDT tolerance. Compared with pre-training, during HDT test subjects' symptom scores in group B were significantly lower than those in group A (P<0.05) and after training decreasing magnitude of heart rate in group B increased significantly (P<0.01). Then mode B to be preferable training method in increasing HDT tolerance was suggested. 2) Two kinds of training modes improved all subjects' orthostatic tolerance. Compared with pre-training, during orthostatic tolerance test increasing magnitude of mean arterial blood pressure in group B increased significantly (P<0.05) and a trend of increasing magnitude of heart rate in group B was appeared smaller than in group A (P<0.10). Mode B to be preferable training method in increasing orthostatic tolerance was suggested too. Repeated body position change training could increase adaptability to blood redistribution in human body. Mode B was preferable training method and would be hopeful to be used in astronaut training.

A Framework to Analyze the Performance of Load Balancing Schemes for Ensembles of Stochastic Simulations

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

Ahn, Tae-Hyuk; Sandu, Adrian; Watson, Layne T.

2015-08-01

Ensembles of simulations are employed to estimate the statistics of possible future states of a system, and are widely used in important applications such as climate change and biological modeling. Ensembles of runs can naturally be executed in parallel. However, when the CPU times of individual simulations vary considerably, a simple strategy of assigning an equal number of tasks per processor can lead to serious work imbalances and low parallel efficiency. This paper presents a new probabilistic framework to analyze the performance of dynamic load balancing algorithms for ensembles of simulations where many tasks are mapped onto each processor, andmore » where the individual compute times vary considerably among tasks. Four load balancing strategies are discussed: most-dividing, all-redistribution, random-polling, and neighbor-redistribution. Simulation results with a stochastic budding yeast cell cycle model are consistent with the theoretical analysis. It is especially significant that there is a provable global decrease in load imbalance for the local rebalancing algorithms due to scalability concerns for the global rebalancing algorithms. The overall simulation time is reduced by up to 25 %, and the total processor idle time by 85 %.« less

Advancing High Current Startup via Localized Helicity Injection in the PEGASUS Toroidal Experiment

NASA Astrophysics Data System (ADS)

Hinson, E. T.; Barr, J. L.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Perry, J. M.; Redd, A. J.; Schlossberg, D. J.

2013-10-01

Non-solenoidal startup via local helicity injection (LHI) and poloidal field induction is used to produce Ip = 0 . 17 MA tokamak discharges. Impurity contamination has been reduced to negligible levels by use of conical frustum cathode geometry and local scraper limiters. Attainable currents are governed by global limits of helicity and energy balance, and Taylor relaxation. A simple lumped parameter model based on these limits is used to project discharge evolution, and indicates that attaining 1 MA in NSTX-U will require LHI-driven effective loop voltages to dominate contributions from dLp / dt . This regime contrasts with results to date and will be tested at 0.3 MA in PEGASUS with a new integrated multi-injector array. Injector impedance characteristics are consistent with magnetically-limited regimes observed in higher-power foilless diodes. Bursts of MHD are measured on time scales of order ~ 100 μ s, and correlate with rapid equilibrium changes, discrete rises in Ip, redistribution of the toroidal current, ion heating (Ti ~ 1 keV), transient drops in injector voltage, and apparent n = 1 line-tied kink activity at the injector. NIMROD simulations of high-field-side HI discharges in PEGASUS are in qualitative agreement, suggesting Ip buildup results from inward propagating toroidal current loops created by intermittent reconnection of injected current streams. Work supported by US DOE Grant DE-FG02-96ER54375.

Improving Aerosol and Visibility Forecasting Capabilities Using Current and Future Generations of Satellite Observations

DTIC Science & Technology

2012-09-30

improving forecast performance over cloudy regions using the Ozone Monitoring Instrument (OMI) Aerosol Index; and 2) preparing for the post-MODIS...meteorological fields, the International Geosphere-Biosphere Programme (IGBP) SW and LW surface characteristics, and an ozone climatology are used as...The primary impact of CALIOP assimilation on the model is the redistribution of mass toward the boundary layer from the free troposphere . For high

Sequence of Key Events in Shoot Gravitropism 1

PubMed Central

Migliaccio, Fernando; Rayle, David L.

1984-01-01

It has recently been shown that asymmetric acid efflux is closely correlated with the gravitropic curvature of plant shoots and roots. The research reported here addresses whether auxin (IAA) redistribution in shoots is the cause or result of asymmetric acid efflux. When abraded sunflower (Helianthus annuus cv Mammoth) hypocotyls are submerged in 20 millimolar neutral buffer, gravicurvature is greatly retarded relative to 0.2 millimolar controls. Nevertheless, in both buffer systems there is a similar redistribution of [3H]IAA toward the lower surface of gravistimulated sunflower hypocotyls. These results suggest that graviperception initiates IAA redistribution, which in turn results in auxin-induced asymmetric H+ efflux across the shoot. This interpretation is reinforced by data showing the effects of removal of the epidermal layers (peeling), osmotic shock, and morphactin treatment on gravicurvature and [3H]IAA redistribution. Peeling and osmotic shock inhibit gravicurvature but not redistribution. Morphactin inhibits both processes but does not inhibit hypocotyl straight growth. PMID:16663606

Development of the electrothermal instability from resistive inclusions

NASA Astrophysics Data System (ADS)

Yu, Edmund; Awe, T. J.; Bauer, B. S.; Yates, K. C.; Yelton, W. G.; Hutchinson, T. M.; Fuelling, S.; McKenzie, B. B.; Peterson, K. J.

2016-10-01

The magneto Rayleigh-Taylor (MRT) instability limits the performance of all magnetically imploded systems. In the case of compressing metal liners, as in the magnetized liner inertial fusion concept, a dominant seed for MRT is believed to be the electrothermal instability (ETI). Here, linear theory predicts the most unstable mode manifests as horizontal (i.e. perpendicular to current flow) bands of heated and expanded metal. However, how do such bands, known as striations, actually develop from a smooth metal surface? Recent experiments on ETI evolution, performed at the University of Nevada, Reno, provide a possible answer: pre-shot characterization of aluminum rods show numerous resistive inclusions, several microns in diameter and distributed throughout the rod. In this work, we use 3D MHD simulation and analytic theory to explore how current redistribution around these isolated inclusions, combined with ETI, can lead to rapid formation of the global striation structures. Later in time, striations expand and form density perturbations much larger than the initial inclusion size. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under DE-AC04-94AL85000.

Optimal redistribution of an urban air quality monitoring network using atmospheric dispersion model and genetic algorithm

NASA Astrophysics Data System (ADS)

Hao, Yufang; Xie, Shaodong

2018-03-01

Air quality monitoring networks play a significant role in identifying the spatiotemporal patterns of air pollution, and they need to be deployed efficiently, with a minimum number of sites. The revision and optimal adjustment of existing monitoring networks is crucial for cities that have undergone rapid urban expansion and experience temporal variations in pollution patterns. The approach based on the Weather Research and Forecasting-California PUFF (WRF-CALPUFF) model and genetic algorithm (GA) was developed to design an optimal monitoring network. The maximization of coverage with minimum overlap and the ability to detect violations of standards were developed as the design objectives for redistributed networks. The non-dominated sorting genetic algorithm was applied to optimize the network size and site locations simultaneously for Shijiazhuang city, one of the most polluted cities in China. The assessment on the current network identified the insufficient spatial coverage of SO2 and NO2 monitoring for the expanding city. The optimization results showed that significant improvements were achieved in multiple objectives by redistributing the original network. Efficient coverage of the resulting designs improved to 60.99% and 76.06% of the urban area for SO2 and NO2, respectively. The redistributing design for multi-pollutant including 8 sites was also proposed, with the spatial representation covered 52.30% of the urban area and the overlapped areas decreased by 85.87% compared with the original network. The abilities to detect violations of standards were not improved as much as the other two objectives due to the conflicting nature between the multiple objectives. Additionally, the results demonstrated that the algorithm was slightly sensitive to the parameter settings, with the number of generations presented the most significant effect. Overall, our study presents an effective and feasible procedure for air quality network optimization at a city scale.

Current concepts of metabolic abnormalities in HIV patients: focus on lipodystrophy.

PubMed

Kolter, Donald P

2003-12-01

HIV infection is associated with a number of metabolic abnormalities, including lipodystrophy, a difficult-to-define disorder whose characteristics include hyperlipidemia, insulin resistance, and fat redistribution. Current data suggest that lipodystrophy is caused by multiple factors. Dual-nucleoside reverse transcriptase inhibitor therapy combined with protease inhibitor therapy has been shown to increase the risk of metabolic abnormalities, but susceptibility independent of drug effects has also been shown. While many of the treatments for the broad range of signs and symptoms of lipodystrophy bring about improvements in patient status, none have been demonstrated to bring about a return to baseline levels.

The role of calcium and calmodulin in the response of roots to gravity

NASA Technical Reports Server (NTRS)

Evans, Michael L.

1992-01-01

There is general agreement that, in roots, the primary detection of the gravitropic signal occurs in the columella cells of the cap and that this results in the generation of a signal that moves into the elongation zone causing the asymmetric growth that leads to downward curvature. Recent work has generated considerable evidence that indicates that auxin is the ultimate mediator of differential growth during root (and shoot) gravitropism. Our studies of the time course of curvature, auxin redistribution and/or adaptation, and electrical potential changes in maize roots have led to the following generalizations: (1) downward curvature begins 18 to 32 min following gravistimulation; (2) asymmetric auxin redistribution across the root cap begins at about the same time as curvature or perhaps slight earlier; (3) there is a lag of approx. 15 min in the response of roots to applied auxin; and (4) gravi-induced changes in intracellular potentials of cortical cells within the elongation zone occur within 30 s following stimulation.

Seismologic applications of GRACE time-variable gravity measurements

NASA Astrophysics Data System (ADS)

Li, Jin; Chen, Jianli; Zhang, Zizhan

2014-04-01

The Gravity Recovery and Climate Experiment (GRACE) has been measuring temporal and spatial variations of mass redistribution within the Earth system since 2002. As large earthquakes cause significant mass changes on and under the Earth's surface, GRACE provides a new means from space to observe mass redistribution due to earthquake deformations. GRACE serves as a good complement to other earthquake measurements because of its extensive spatial coverage and being free from terrestrial restriction. During its over 10 years mission, GRACE has successfully detected seismic gravitational changes of several giant earthquakes, which include the 2004 Sumatra-Andaman earthquake, 2010 Maule (Chile) earthquake, and 2011 Tohoku-Oki (Japan) earthquake. In this review, we describe by examples how to process GRACE time-variable gravity data to retrieve seismic signals, and summarize the results of recent studies that apply GRACE observations to detect co- and post-seismic signals and constrain fault slip models and viscous lithospheric structures. We also discuss major problems and give an outlook in this field of GRACE application.

A study of trends and techniques for space base electronics

NASA Technical Reports Server (NTRS)

Trotter, J. D.; Wade, T. E.; Gassaway, J. D.; Mahmood, Q.

1978-01-01

A sputtering system was developed to deposit aluminum and aluminum alloys by the dc sputtering technique. This system is designed for a high level of cleanliness and for monitoring the deposition parameters during film preparation. This system is now ready for studying the deposition and annealing parameters upon double-level metal preparation. A technique recently applied for semiconductor analysis, the finite element method, was studied for use in the computer modeling of two dimensional MOS transistor structures. It was concluded that the method has not been sufficiently well developed for confident use at this time. An algorithm was developed for confident use at this time. An algorithm was developed for implementing a computer study which is based upon the finite difference method. The program which was developed was modified and used to calculate redistribution data for boron and phosphorous which had been predeposited by ion implantation with range and straggle conditions. Data were generated for 111 oriented SOS films with redistribution in N2, dry O2 and steam ambients.

The effect of unsteadiness on the time-mean thermal loads in a turbine stage

NASA Technical Reports Server (NTRS)

Kirtley, K. R.; Celestina, M. L.; Adamczyk, J. J.

1993-01-01

Two steady numerical analysis methods and one unsteady method are used to study the viscous three-dimensional flow in the middle stage of the Pratt & Whitney alternate design Space Shuttle Main Engine fuel turbine. The principal characteristic of this flow is that the secondary flows generated in the rotor blade reconfigure a radial inlet total temperature distortion into one with a pitchwise exit hot streak distortion. Secondary flows in the following vane redistribute the radial variation while unsteadiness causes a segregation of hot and cold flow from the hot streak within the vane. Such redistribution and segregation can lead to unexpected thermal loads and reduced durability. The physical phenomena and the ability of a steady analysis to capture them are investigated by performing a numerical experiment whereby the results of the two steady analysis methods are compared to the time-mean of the unsteady simulation. The flow physics related to the segregation and mixing of total temperature are discussed.

Modeling and Measurement of Sustained Loading and Temperature-Dependent Deformation of Carbon Fiber-Reinforced Polymer Bonded to Concrete.

PubMed

Jeong, Yoseok; Lee, Jaeha; Kim, WooSeok

2015-01-29

This paper aims at presenting the effects of short-term sustained load and temperature on time-dependent deformation of carbon fiber-reinforced polymer (CFRP) bonded to concrete and pull-off strength at room temperature after the sustained loading period. The approach involves experimental and numerical analysis. Single-lap shear specimens were used to evaluate temperature and short-term sustained loading effects on time-dependent behavior under sustained loading and debonding behavior under pull-off loading after a sustained loading period. The numerical model was parameterized with experiments on the concrete, FRP, and epoxy. Good correlation was seen between the numerical results and single-lap shear experiments. Sensitivity studies shed light on the influence of temperature, epoxy modulus, and epoxy thickness on the redistribution of interfacial shear stress during sustained loading. This investigation confirms the hypothesis that interfacial stress redistribution can occur due to sustained load and elevated temperature and its effect can be significant.

Modeling and Measurement of Sustained Loading and Temperature-Dependent Deformation of Carbon Fiber-Reinforced Polymer Bonded to Concrete

PubMed Central

Jeong, Yoseok; Lee, Jaeha; Kim, WooSeok

2015-01-01

This paper aims at presenting the effects of short-term sustained load and temperature on time-dependent deformation of carbon fiber-reinforced polymer (CFRP) bonded to concrete and pull-off strength at room temperature after the sustained loading period. The approach involves experimental and numerical analysis. Single-lap shear specimens were used to evaluate temperature and short-term sustained loading effects on time-dependent behavior under sustained loading and debonding behavior under pull-off loading after a sustained loading period. The numerical model was parameterized with experiments on the concrete, FRP, and epoxy. Good correlation was seen between the numerical results and single-lap shear experiments. Sensitivity studies shed light on the influence of temperature, epoxy modulus, and epoxy thickness on the redistribution of interfacial shear stress during sustained loading. This investigation confirms the hypothesis that interfacial stress redistribution can occur due to sustained load and elevated temperature and its effect can be significant. PMID:28787948

Knowing One's Lot in Life versus Climbing the Social Ladder: The Formation of Redistributive Preferences in Urban China

ERIC Educational Resources Information Center

Smyth, Russell; Mishra, Vinod; Qian, Xiaolei

2010-01-01

This paper examines, how individual preferences for redistribution in general and redistribution to improve access to education, improve social protection for the poor, reduce income inequality and reduce unemployment depend on beliefs about what determines one's lot in life and self-assessed prospects for climbing the social ladder in urban…

Inequality and Redistribution Policy Issues: Principles and Swedish Experience; Comment on Lindbeck's Paper [and] Discussion Paper.

ERIC Educational Resources Information Center

Lindbeck, Assar

Alternative methods of redistribution policy in mixed economies are compared in this paper. The paper deals with the objectives, methods, and problems in redistribution policy. The chief objective is to highlight principles and general problems, drawing heavily on the experiences of Sweden. This country is chosen as a case study since attempts to…

Medicine shortages: a commentary on causes and mitigation strategies.

PubMed

Iyengar, Swathi; Hedman, Lisa; Forte, Gilles; Hill, Suzanne

2016-09-29

Shortages of medicines and vaccines have been reported in countries of all income levels in recent years. Shortages can result from one or multiple causes, including shortages of raw materials, manufacturing capacity problems, industry consolidation, marketing practices, and procurement and supply chain management. Existing approaches to mitigate shortages include advance notice systems managed through medicine regulatory authorities, special programmes that track medicines, and interventions to improve efficiency of the medicine supply chain. Redistribution of supplies at the national level can mitigate some shortages in the short term. International redistribution and exceptional regulatory approvals may be used in limited circumstances, with the understanding that such approaches are complex and may introduce cost and quality risks. If it is necessary to prioritise patients to receive a medicine that is in shortage, evidence-based practice should be used to ensure optimal allocation. Important steps in reducing medicine shortages and their impact include identifying medicines that are most at risk, developing reporting systems to share information on current and emerging shortages, and improving data from medicine supply chains.

Multiscale empirical modeling of the geomagnetic field: From storms to substorms

NASA Astrophysics Data System (ADS)

Stephens, G. K.; Sitnov, M. I.; Korth, H.; Gkioulidou, M.; Ukhorskiy, A. Y.; Merkin, V. G.

2017-12-01

An advanced version of the TS07D empirical geomagnetic field model, herein called SST17, is used to model the global picture of the geomagnetic field and its characteristic variations on both storm and substorm scales. The new SST17 model uses two regular expansions describing the equatorial currents with each having distinctly different scales, one corresponding to a thick and one to a thin current sheet relative to the thermal ion gyroradius. These expansions have an arbitrary distribution of currents in the equatorial plane that is constrained only by magnetometer data. This multi-scale description allows one to reproduce the current sheet thinning during the growth phase. Additionaly, the model uses a flexible description of field-aligned currents that reproduces their spiral structure at low altitudes and provides a continuous transition from region 1 to region 2 current systems. The empirical picture of substorms is obtained by combining magnetometer data from Geotail, THEMIS, Van Allen Probes, Cluster II, Polar, IMP-8, GOES 8, 9, 10 and 12 and then binning this data based on similar values of the auroral index AL, its time derivative and the integral of the solar wind electric field parameter (from ACE, Wind, and IMP-8) in time over substorm scales. The performance of the model is demonstrated for several events, including the 3 July 2012 substorm, which had multi-probe coverage and a series of substorms during the March 2008 storm. It is shown that the AL binning helps reproduce dipolarization signatures in the northward magnetic field Bz, while the solar wind electric field integral allows one to capture the current sheet thinning during the growth phase. The model allows one to trace the substorm dipolarization from the tail to the inner magnetosphere where the dipolarization of strongly stretched tail field lines causes a redistribution of the tail current resulting in an enhancement of the partial ring current in the premidnight sector.

Use of a (137)Cs re-sampling technique to investigate temporal changes in soil erosion and sediment mobilisation for a small forested catchment in southern Italy.

PubMed

Porto, Paolo; Walling, Des E; Alewell, Christine; Callegari, Giovanni; Mabit, Lionel; Mallimo, Nicola; Meusburger, Katrin; Zehringer, Markus

2014-12-01

Soil erosion and both its on-site and off-site impacts are increasingly seen as a serious environmental problem across the world. The need for an improved evidence base on soil loss and soil redistribution rates has directed attention to the use of fallout radionuclides, and particularly (137)Cs, for documenting soil redistribution rates. This approach possesses important advantages over more traditional means of documenting soil erosion and soil redistribution. However, one key limitation of the approach is the time-averaged or lumped nature of the estimated erosion rates. In nearly all cases, these will relate to the period extending from the main period of bomb fallout to the time of sampling. Increasing concern for the impact of global change, particularly that related to changing land use and climate change, has frequently directed attention to the need to document changes in soil redistribution rates within this period. Re-sampling techniques, which should be distinguished from repeat-sampling techniques, have the potential to meet this requirement. As an example, the use of a re-sampling technique to derive estimates of the mean annual net soil loss from a small (1.38 ha) forested catchment in southern Italy is reported. The catchment was originally sampled in 1998 and samples were collected from points very close to the original sampling points again in 2013. This made it possible to compare the estimate of mean annual erosion for the period 1954-1998 with that for the period 1999-2013. The availability of measurements of sediment yield from the catchment for parts of the overall period made it possible to compare the results provided by the (137)Cs re-sampling study with the estimates of sediment yield for the same periods. In order to compare the estimates of soil loss and sediment yield for the two different periods, it was necessary to establish the uncertainty associated with the individual estimates. In the absence of a generally accepted procedure for such calculations, key factors influencing the uncertainty of the estimates were identified and a procedure developed. The results of the study demonstrated that there had been no significant change in mean annual soil loss in recent years and this was consistent with the information provided by the estimates of sediment yield from the catchment for the same periods. The study demonstrates the potential for using a re-sampling technique to document recent changes in soil redistribution rates. Copyright © 2014. Published by Elsevier Ltd.

Modeling Microgravity Induced Fluid Redistribution Autoregulatory and Hydrostatic Enhancements

NASA Technical Reports Server (NTRS)

Myers, J. G.; Werner, C.; Nelson, E. S.; Feola, A.; Raykin, J.; Samuels, B.; Ethier, C. R.

2017-01-01

Space flight induces a marked cephalad (headward) redistribution of blood and interstitial fluid potentially resulting in a loss of venous tone and reduction in heart muscle efficiency upon introduction into the microgravity environment. Using various types of computational models, we are investigating how this fluid redistribution may induce intracranial pressure changes, relevant to reported reductions in astronaut visual acuity, part of the Visual Impairment and Intracranial Pressure (VIIP) syndrome. Methods: We utilize a lumped parameter cardiovascular system (CVS) model, augmented by compartments comprising the cerebral spinal fluid (CSF) space, as the primary tool to describe how microgravity, and the associated lack of hydrostatic gradient, impacts fluid redistribution. Models of ocular fluid pressures and biomechanics then accept the output of the above model as boundary condition input to allow more detailed, local analysis (see IWS Abstract by Ethier et al.). Recently, we enhanced the capabilities our previously reported CVS model through the implementation of robust autoregulatory mechanisms and a more fundamental approach to the implementation of hydrostatic mechanisms. Modifying the approach of Blanco et al., we implemented auto-regulation in a quasi-static manner, as an averaged effect across the span of one heartbeat. This approach reduced the higher frequency perturbations from the regulatory mechanism and was intended to allow longer simulation times (days) than models that implement within-beat regulatory mechanisms (minutes). A more fundamental approach to hydrostatics was implemented by a quasi-1D approach, in which compartment descriptions include compartment length, orientation and relative position, allowed for modeling of body orientation, relative body positioning and, in the future, alternative gravity environments. At this time the inclusion of hydrostatic mechanisms supplies additional capabilities to train and validate the CVS model with terrestrial data. Results and Conclusions: With the implementation of auto-regulation and hydrostatic modeling capabilities, the model performs as expected in the maintaining the CA (Central Artery) compartment pressure when simulating orientations ranging from supine to standing. The model appears to generally overpredict heart rate and thus cardiac output, possibly indicating sensitivity to the nominal heart rate, which is used as an initial set point of the regulation mechanisms. Despite this sensitivity, the model performs consistently for many hours of simulation time, indicating the success of our quasi-static implementation approach.

Phase Transformation Temperatures and Solute Redistribution in a Quaternary Zirconium Alloy

NASA Astrophysics Data System (ADS)

Cochrane, C.; Daymond, M. R.

2018-05-01

This study investigates the phase stability and redistribution of solute during heating and cooling of a quaternary zirconium alloy, Excel (Zr-3.2Sn-0.8Mo-0.8Nb). Time-of-flight neutron diffraction data are analyzed using a novel Vegard's law-based approach to determine the phase fractions and location of substitutional solute atoms in situ during heating from room temperature up to 1050 °C. It is seen that this alloy exhibits direct nucleation of the β Zr phase from martensite during tempering, and stable retention of the β Zr phase to high temperatures, unlike other two-phase zirconium alloys. The transformation strains resulting from the α \\leftrightarrow β transformation are shown to have a direct impact on the development of microstructure and crystallographic texture.

SAGE: The Self-Adaptive Grid Code. 3

NASA Technical Reports Server (NTRS)

Davies, Carol B.; Venkatapathy, Ethiraj

1999-01-01

The multi-dimensional self-adaptive grid code, SAGE, is an important tool in the field of computational fluid dynamics (CFD). It provides an efficient method to improve the accuracy of flow solutions while simultaneously reducing computer processing time. Briefly, SAGE enhances an initial computational grid by redistributing the mesh points into more appropriate locations. The movement of these points is driven by an equal-error-distribution algorithm that utilizes the relationship between high flow gradients and excessive solution errors. The method also provides a balance between clustering points in the high gradient regions and maintaining the smoothness and continuity of the adapted grid, The latest version, Version 3, includes the ability to change the boundaries of a given grid to more efficiently enclose flow structures and provides alternative redistribution algorithms.

Dynamo magnetic field-induced angular momentum transport in protostellar nebulae - The 'minimum mass' protosolar nebula

NASA Technical Reports Server (NTRS)

Stepinski, T. F.; Levy, E. H.

1990-01-01

Magnetic torques can produce angular momentum redistribution in protostellar nebulas. Dynamo magnetic fields can be generated in differentially rotating and turbulent nebulas and can be the source of magnetic torques that transfer angular momentum from a protostar to a disk, as well as redistribute angular momentum within a disk. A magnetic field strength of 100-1000 G is needed to transport the major part of a protostar's angular momentum into a surrounding disk in a time characteristic of star formation, thus allowing formation of a solar-system size protoplanetary nebula in the usual 'minimum-mass' model of the protosolar nebula. This paper examines the possibility that a dynamo magnetic field could have induced the needed angular momentum transport from the proto-Sun to the protoplanetary nebula.

Ground-based optical atomic clocks as a tool to monitor vertical surface motion

NASA Astrophysics Data System (ADS)

Bondarescu, Ruxandra; Schärer, Andreas; Lundgren, Andrew; Hetényi, György; Houlié, Nicolas; Jetzer, Philippe; Bondarescu, Mihai

2015-09-01

According to general relativity, a clock experiencing a shift in the gravitational potential ΔU will measure a frequency change given by Δf/f ≈ ΔU/c2. The best clocks are optical clocks. After about 7 hr of integration they reach stabilities of Δf/f ˜ 10-18 and can be used to detect changes in the gravitational potential that correspond to vertical displacements of the centimetre level. At this level of performance, ground-based atomic clock networks emerge as a tool that is complementary to existing technology for monitoring a wide range of geophysical processes by directly measuring changes in the gravitational potential. Vertical changes of the clock's position due to magmatic, post-seismic or tidal deformations can result in measurable variations in the clock tick rate. We illustrate the geopotential change arising due to an inflating magma chamber using the Mogi model and apply it to the Etna volcano. Its effect on an observer on the Earth's surface can be divided into two different terms: one purely due to uplift (free-air gradient) and one due to the redistribution of matter. Thus, with the centimetre-level precision of current clocks it is already possible to monitor volcanoes. The matter redistribution term is estimated to be 3 orders of magnitude smaller than the uplift term. Additionally, clocks can be compared over distances of thousands of kilometres over short periods of time, which improves our ability to monitor periodic effects with long wavelength like the solid Earth tide.

Landscape analysis of methane flux across complex terrain

NASA Astrophysics Data System (ADS)

Kaiser, K. E.; McGlynn, B. L.; Dore, J. E.

2014-12-01

Greenhouse gas (GHG) fluxes into and out of the soil are influenced by environmental conditions resulting in landscape-mediated patterns of spatial heterogeneity. The temporal variability of inputs (e.g. precipitation) and internal redistribution (e.g. groundwater flow) and dynamics (e.g. microbial communities) make predicating these fluxes challenging. Complex terrain can provide a laboratory for improving understanding of the spatial patterns, temporal dynamics, and drivers of trace gas flux rates, requisite to constraining current GHG budgets and future scenarios. Our research builds on previous carbon cycle research at the USFS Tenderfoot Creek Experimental Forest, Little Belt Mountains, Montana that highlighted the relationships between landscape position and seasonal CO2 efflux, induced by the topographic redistribution of water. Spatial patterns and landscape scale mediation of CH4 fluxes in seasonally aerobic soils have not yet been elucidated. We measured soil methane concentrations and fluxes across a full range of landscape positions, leveraging topographic and seasonal gradients, to examine the relationships between environmental variables, hydrologic dynamics, and CH4 production and consumption. We determined that a threshold of ~30% VWC distinguished the direction of flux at individual time points, with the riparian area and uplands having distinct source/sink characteristics respectively. Riparian locations were either strong sources or fluctuated between sink and source behavior, resulting in near neutral seasonal flux. Upland sites however, exhibited significant relationships between sink strength and topographic/energy balance indices. Our results highlight spatial and temporal coherence to landscape scale heterogeneity of CH4 dynamics that can improve estimates of landscape scale CH4 balances and sensitivity to change.

Fluorescence intermittency originates from reclustering in two-dimensional organic semiconductors

NASA Astrophysics Data System (ADS)

Ruth, Anthony; Hayashi, Michitoshi; Zapol, Peter; Si, Jixin; McDonald, Matthew P.; Morozov, Yurii V.; Kuno, Masaru; Jankó, Boldizsár

2017-02-01

Fluorescence intermittency or blinking is observed in nearly all nanoscale fluorophores. It is characterized by universal power-law distributions in on- and off-times as well as 1/f behaviour in corresponding emission power spectral densities. Blinking, previously seen in confined zero- and one-dimensional systems has recently been documented in two-dimensional reduced graphene oxide. Here we show that unexpected blinking during graphene oxide-to-reduced graphene oxide photoreduction is attributed, in large part, to the redistribution of carbon sp2 domains. This reclustering generates fluctuations in the number/size of emissive graphenic nanoclusters wherein multiscale modelling captures essential experimental aspects of reduced graphene oxide's absorption/emission trajectories, while simultaneously connecting them to the underlying photochemistry responsible for graphene oxide's reduction. These simulations thus establish causality between currently unexplained, long timescale emission intermittency in a quantum mechanical fluorophore and identifiable chemical reactions that ultimately lead to switching between on and off states.

Atomic layer deposition modified track-etched conical nanochannels for protein sensing.

PubMed

Wang, Ceming; Fu, Qibin; Wang, Xinwei; Kong, Delin; Sheng, Qian; Wang, Yugang; Chen, Qiang; Xue, Jianming

2015-08-18

Nanopore-based devices have recently become popular tools to detect biomolecules at the single-molecule level. Unlike the long-chain nucleic acids, protein molecules are still quite challenging to detect, since the protein molecules are much smaller in size and usually travel too fast through the nanopore with poor signal-to-noise ratio of the induced transport signals. In this work, we demonstrate a new type of nanopore device based on atomic layer deposition (ALD) Al2O3 modified track-etched conical nanochannels for protein sensing. These devices show very promising properties of high protein (bovine serum albumin) capture rate with well time-resolved transport signals and excellent signal-to-noise ratio for the transport events. Also, a special mechanism involving transient process of ion redistribution inside the nanochannel is proposed to explain the unusual biphasic waveshapes of the current change induced by the protein transport.

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

Ruth, Anthony; Hayashi, Michitoshi; Zapol, Peter

Fluorescence intermittency or blinking is observed in nearly all nanoscale fluorophores. It is characterized by universal power-law distributions in on- and off-times as well as 1/f behaviour in corresponding emission power spectral densities. Blinking, previously seen in confined zero- and one-dimensional systems has recently been documented in two-dimensional reduced graphene oxide. Here we show that unexpected blinking during graphene oxide-to-reduced graphene oxide photoreduction is attributed, in large part, to the redistribution of carbon sp 2 domains. This reclustering generates fluctuations in the number/size of emissive graphenic nanoclusters wherein multiscale modelling captures essential experimental aspects of reduced graphene oxide’s absorption/emission trajectories,more » while simultaneously connecting them to the underlying photochemistry responsible for graphene oxide’s reduction. These simulations thus establish causality between currently unexplained, long timescale emission intermittency in a quantum mechanical fluorophore and identifiable chemical reactions that ultimately lead to switching between on and off states.« less

Using MOEA with Redistribution and Consensus Branches to Infer Phylogenies.

PubMed

Min, Xiaoping; Zhang, Mouzhao; Yuan, Sisi; Ge, Shengxiang; Liu, Xiangrong; Zeng, Xiangxiang; Xia, Ningshao

2017-12-26

In recent years, to infer phylogenies, which are NP-hard problems, more and more research has focused on using metaheuristics. Maximum Parsimony and Maximum Likelihood are two effective ways to conduct inference. Based on these methods, which can also be considered as the optimal criteria for phylogenies, various kinds of multi-objective metaheuristics have been used to reconstruct phylogenies. However, combining these two time-consuming methods results in those multi-objective metaheuristics being slower than a single objective. Therefore, we propose a novel, multi-objective optimization algorithm, MOEA-RC, to accelerate the processes of rebuilding phylogenies using structural information of elites in current populations. We compare MOEA-RC with two representative multi-objective algorithms, MOEA/D and NAGA-II, and a non-consensus version of MOEA-RC on three real-world datasets. The result is, within a given number of iterations, MOEA-RC achieves better solutions than the other algorithms.

The implementation of Prime Vendor Europe and its successful impact on an overseas naval medical treatment facility.

PubMed

Koerner, S D; Anaya, M A

1996-10-01

Prime Vendor Europe (PVE) is the commercial pharmaceutical ordering and delivery program that is revolutionizing overseas health care delivery at military health care treatment facilities located in the European theater. Mirroring civilian programs already available and replacing the Federal Supply System, PVE offers many benefits never before realized at overseas military health care treatment facilities, including: diminished order turnaround times with resultant decreased Operating Target requirements; rapid order confirmation after order placement; lower carrying costs and inventory needs; better dating of pharmaceuticals received; redistribution and increased efficiency of the current manhours needed to operate a pharmacy supply system; order tracking capabilities; and enhancement of the present cooperative and constructive dichotomous relationship between medical logistics and pharmacy regarding pharmaceutical purchasing practices. This paper will explore the fundamentals, past performance, continuous quality improvement of logistical functions, frame-work establishment for PVE, implementation of PVE, and subsequent observed command benefits of PVE realization.

Tunable quasiparticle trapping in Meissner and vortex states of mesoscopic superconductors.

PubMed

Taupin, M; Khaymovich, I M; Meschke, M; Mel'nikov, A S; Pekola, J P

2016-03-16

Nowadays, superconductors serve in numerous applications, from high-field magnets to ultrasensitive detectors of radiation. Mesoscopic superconducting devices, referring to those with nanoscale dimensions, are in a special position as they are easily driven out of equilibrium under typical operating conditions. The out-of-equilibrium superconductors are characterized by non-equilibrium quasiparticles. These extra excitations can compromise the performance of mesoscopic devices by introducing, for example, leakage currents or decreased coherence time in quantum devices. By applying an external magnetic field, one can conveniently suppress or redistribute the population of excess quasiparticles. In this article, we present an experimental demonstration and a theoretical analysis of such effective control of quasiparticles, resulting in electron cooling both in the Meissner and vortex states of a mesoscopic superconductor. We introduce a theoretical model of quasiparticle dynamics, which is in quantitative agreement with the experimental data.

Tunable quasiparticle trapping in Meissner and vortex states of mesoscopic superconductors

PubMed Central

Taupin, M.; Khaymovich, I. M.; Meschke, M.; Mel'nikov, A. S.; Pekola, J. P.

2016-01-01

Nowadays, superconductors serve in numerous applications, from high-field magnets to ultrasensitive detectors of radiation. Mesoscopic superconducting devices, referring to those with nanoscale dimensions, are in a special position as they are easily driven out of equilibrium under typical operating conditions. The out-of-equilibrium superconductors are characterized by non-equilibrium quasiparticles. These extra excitations can compromise the performance of mesoscopic devices by introducing, for example, leakage currents or decreased coherence time in quantum devices. By applying an external magnetic field, one can conveniently suppress or redistribute the population of excess quasiparticles. In this article, we present an experimental demonstration and a theoretical analysis of such effective control of quasiparticles, resulting in electron cooling both in the Meissner and vortex states of a mesoscopic superconductor. We introduce a theoretical model of quasiparticle dynamics, which is in quantitative agreement with the experimental data. PMID:26980225

Preferential flow, connectivity and the principle of "minimum time to equilibrium": a new perspective on environmental water flow

NASA Astrophysics Data System (ADS)

Zehe, E.; Blume, T.; Bloeschl, G.

2008-12-01

Preferential/rapid flow and transport is known as one key process in soil hydrology for more than 20 years. It seems to be rather the rule, than the exception. It occurs in soils, in surface rills and river networks. If connective preferential are present at any scale, they crucially control water flow and solute transport. Why? Is there an underlying principle? If energy is conserved a system follows Fermat's principle of minimum action i.e. it follows the trajectory that minimise the integral of the total energy/ La Grangian over time. Hydrological systems are, however, non-conservative as surface and subsurface water flows dissipate energy. From thermodynamics it is well known that natural processes minimize the free energy of the system. For hydrological systems we suggest, therefore, that flow in a catchment arranges in such a way that time to a minimum of free energy becomes minimal for a given rainfall input (disturbance) and under given constraints. Free energy in a soil is determined by potential energy and capillary energy. The pore size distribution of the soil, soil structures, depth to groundwater and most important vegetation make up the constraints. The pore size distribution determines whether potential energy or capillarity dominates the free energy of the soil system. The first term is minimal when the pore space is completely de-saturated the latter becomes minimal at soil saturation. Hence, the soil determines a) the amount of excess (gravity) water that has to be exported from the soil to reach a minimum state of free energy and b) whether redistribution or groundwater recharge is more efficient to reach that equilibrium. On the other hand, the pore size distribution of the soil and the connectivity of preferential pathways (root channels, worm holes and cracks) determine flow velocities and the redistribution of water within the pore space. As water flow and ground water recharge are fast in sandy soils and capillary energy is of minor importance, connective preferential pathways do not mean any advantage for an efficient transition to an equilibrium in these systems. In fine grained soils Darcy velocities and therefore redistribution of water is 2-4 orders of magnitude slower. As capillary energy dominates in these soils an effective redistribution of water within the pore space is crucial for a fast transition of system to an equilibrium state. Connective preferential pathways ore even cracks allow a faster redistribution of water and seem therefore necessary for a fast transition into a state of minimum free energy. The suggested principle "of minimum time to equilibrium" may explain the "advantage" of preferential flow as a much more efficient dissipation of energy in fine grained soils and therefore why connective preferential pathways control environmental flow. From a fundamental, long term perspective the principle may help us to understand whether and why soil structures and even cracks evolve in different landscapes and climates and b) to link soil hydrology and (landscape) ecology. Along the lines the proposed study will present model results to test the stated hypothesis.

[Task redistribution in Dutch dental care in relation to dental hygienists' job satisfaction].

PubMed

Jerkovic, K; van Offenbeek, M A G; van der Schans, C P

2010-05-01

In research into a professional cross-section of dental hygienists, we studied the extent to which task redistribution has an influence on job satisfaction. The research among randomly chosen dental hygienists consisted of questions about organizational and personal characteristics, the set of assigned tasks, task characteristics and job satisfaction. The respondents were divided into 3 clusters which differed in the breadth of their sets of tasks. Although prevention and periodontology services remain the core tasks in dental hygienists' jobs, the degree of task redistribution differed strongly from cluster to cluster. Respondents with a considerable degree of task redistribution experienced the most task variation, but scored significantly lower on the task characteristics autonomy, feedback, task identity and task importance. This explains why redistribution does not directly correspond with a greater degree of job satisfaction. Moreover, it is precisely the dental hygienists with a broad set of tasks who are significantly less satisfied with their salary than those with a traditional set of tasks.

Unequal views of inequality: Cross-national support for redistribution 1985-2011.

PubMed

VanHeuvelen, Tom

2017-05-01

This research examines public views on government responsibility to reduce income inequality, support for redistribution. While individual-level correlates of support for redistribution are relatively well understood, many questions remain at the country-level. Therefore, I examine how country-level characteristics affect aggregate support for redistribution. I test explanations of aggregate support using a unique dataset combining 18 waves of the International Social Survey Programme and European Social Survey. Results from mixed-effects logistic regression and fixed-effects linear regression models show two primary and contrasting effects. States that reduce inequality through bundles of tax and transfer policies are rewarded with more supportive publics. In contrast, economic development has a seemingly equivalent and dampening effect on public support. Importantly, the effect of economic development grows at higher levels of development, potentially overwhelming the amplifying effect of state redistribution. My results therefore suggest a fundamental challenge to proponents of egalitarian politics. Copyright © 2016 Elsevier Inc. All rights reserved.

Local redistribution of blood under the effect of fixation stress against a background of hypokinesia

NASA Technical Reports Server (NTRS)

Kovalev, O. A.; Lysak, V. F.; Severovostokova, V. I.; Shermetevskaya, S. K.

1980-01-01

Fixation stress was used as a model of emotional disturbance. The effect of previous restrictions on mobility on the local redistribution of blood resulting from fixation stress was examined. Disturbances in carbohydrate which result from prolonged hypokinesia was studied. Radioactivity was used to determine the local redistribution of blood. Modified factor analysis was used to study the results of the experiment.

Verifiable Secret Redistribution

DTIC Science & Technology

2001-10-01

but they are not trusted with secret. Thus, we require a protocol for redistribution without reconstruction of the secret . We also require...verification that the new shareholders have valid shares (ones that can be used to reconstruct the secret ). We present a new protocol to perform non...secret to shareholders in Shamir’s (m,n) threshold scheme (one in which we require m of n shares to reconstruct the secret ), and wish to redistribute the

Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna.

PubMed

Priyadarshini, K V R; Prins, Herbert H T; de Bie, Steven; Heitkönig, Ignas M A; Woodborne, Stephan; Gort, Gerrit; Kirkman, Kevin; Fry, Brian; de Kroon, Hans

2014-04-01

A key question in savanna ecology is how trees and grasses coexist under N limitation. We used N stable isotopes and N content to study N source partitioning across seasons from trees and associated grasses in a semi-arid savanna. We also used (15)N tracer additions to investigate possible redistribution of N by trees to grasses. Foliar stable N isotope ratio (δ(15)N) values were consistent with trees and grasses using mycorrhiza-supplied N in all seasons except in the wet season when they switched to microbially fixed N. The dependence of trees and grasses on mineralized soil N seemed highly unlikely based on seasonal variation in mineralization rates in the Kruger Park region. Remarkably, foliar δ(15)N values were similar for all three tree species differing in the potential for N fixation through nodulation. The tracer experiment showed that N was redistributed by trees to understory grasses in all seasons. Our results suggest that the redistribution of N from trees to grasses and uptake of N was independent of water redistribution. Although there is overlap of N sources between trees and grasses, dependence on biological sources of N coupled with redistribution of subsoil N by trees may contribute to the coexistence of trees and grasses in semi-arid savannas.

Matrix metalloproteinase-2-mediated occludin degradation and caveolin-1-mediated claudin-5 redistribution contribute to blood-brain barrier damage in early ischemic stroke stage.

PubMed

Liu, Jie; Jin, Xinchun; Liu, Ke J; Liu, Wenlan

2012-02-29

Blood-brain barrier (BBB) disruption occurs early enough to be within the thrombolytic time window, and this early ischemic BBB damage is closely associated with hemorrhagic transformation and thus emerging as a promising target for reducing the hemorrhagic complications of thrombolytic stroke therapy. However, the mechanisms underlying early ischemic BBB damage remain poorly understood. Here, we investigated the early molecular events of ischemic BBB damage using in vitro oxygen-glucose deprivation (OGD) and in vivo rat middle cerebral artery occlusion (MCAO) models. Exposure of bEND3 monolayer to OGD for 2 h significantly increased its permeability to FITC-labeled dextran and promoted the secretion of metalloproteinase-2 and -9 (MMP-2/9) and cytosolic translocation of caveolin-1 (Cav-1). This same OGD treatment also led to rapid degradation of tight junction protein occludin and dissociation of claudin-5 from the cytoskeleton, which contributed to OGD-induced endothelial barrier disruption. Using selective MMP-2/9 inhibitor SB-3CT (2-[[(4-phenoxyphenyl)sulfonyl]methyl]-thiirane) or their neutralizing antibodies or Cav-1 siRNA, we found that MMP-2 was the major enzyme mediating OGD-induced occludin degradation, while Cav-1 was responsible for claudin-5 redistribution. The interaction between Cav-1 and claudin-5 was further confirmed by coimmunoprecipitation. Consistent with these in vitro findings, we observed fluorescence tracer extravasation, increased gelatinolytic activity, and elevated interstitial MMP-2 levels in ischemic subcortical tissue after 2 h MCAO. Moreover, occludin protein loss and claudin-5 redistribution were detected in ischemic cerebromicrovessels. These data indicate that cerebral ischemia initiates two rapid parallel processes, MMP-2-mediated occludin degradation and Cav-1-mediated claudin-5 redistribution, to cause BBB disruption at early stroke stages relevant to acute thrombolysis.

Matrix metalloproteinase-2-mediated occludin degradation and caveolin-1-mediated claudin-5 redistribution contribute to blood brain barrier damage in early ischemic stroke stage

PubMed Central

Liu, Jie; Jin, Xinchun; Liu, Ke J.; Liu, Wenlan

2012-01-01

Blood brain barrier (BBB) disruption occurs early enough to be within the thrombolytic time window, and this early ischemic BBB damage is closely associated with hemorrhagic transformation and thus emerging as a promising target for reducing the hemorrhagic complications of thrombolytic stroke therapy. However, the mechanisms underlying early ischemic BBB damage remain poorly understood. Here we investigated the early molecular events of ischemic BBB damage using in vitro oxygen-glucose deprivation (OGD) and in vivo rat middle cerebral artery occlusion (MCAO) models. Exposure of bEND3 monolayer to OGD for 2 h significantly increased its permeability to FITC-labeled dextran, and promoted the secretion of metalloproteinase-2 and 9 (MMP-2/9) and cytosolic translocation of caveolin-1 (Cav-1). This same OGD treatment also led to rapid degradation of tight junction protein occludin and dissociation of claudin-5 from the cytoskeleton, which contributed to OGD-induced endothelial barrier disruption. Using selective MMP-2/9 inhibitor SB-3CT or their neutralizing antibodies or Cav-1 siRNA, we found that MMP-2 was the major enzyme mediating OGD-induced occludin degradation, while Cav-1 was responsible for claudin-5 redistribution. The interaction between Cav-1 and claudin-5 was further confirmed by coimmunoprecipitation. Consistent with these in vitro findings, we observed fluorescence tracer extravasation, increased gelatinolytic activity and elevated interstitial MMP-2 levels in ischemic subcortical tissue after 2-h MCAO. Moreover, occludin protein loss and claudin-5 redistribution were detected in ischemic cerebromicrovessels. These data indicate that cerebral ischemia initiates two rapid parallel processes, MMP-2-mediated occludin degradation and Cav-1-mediated claudin-5 redistribution, to cause BBB disruption at early stroke stages relevant to acute thrombolysis. PMID:22378877

The Geospace Plume: Multi-scale Magnetosphere-Ionosphere Dynamics During the 17 March 2015 Great Storm

NASA Astrophysics Data System (ADS)

Erickson, P. J.; Foster, J. C.; Walsh, B.; Wygant, J. R.; Zhang, S.

2015-12-01

A number of studies over the past three decades have developed an increased understanding of the important redistribution of cold plasma from the ionosphere and inner magnetosphere to other elements of the near-Earth geospace system including the cusp, magnetopause, polar cap, and magnetotail. This redistribution process, especially prevalent during strong geomagnetic storm forcing, has been observed using a wide range of techniques encompassing ground-based and space-based imaging, modeling, and in-situ data. The large diversity of characteristics and location of these separate measurements and models has been reflected in a similarly large variety of nomenclature describing various aspects of the process, e.g. the plasmaspheric surge and drainage plume, storm enhanced density, sub-auroral polarization stream mass flow, and others. To emphasize the interconnections among these magnetosphere and ionosphere observations, we introduce the geospace plume as a unifying concept that recognizes cold plasma redistribution as a global coupling phenomenon, linking mid and sub-auroral ionospheric regions with high latitude cusp heavy ion outflow to the magnetopause and into the magnetotail. Cold redistributed plasma of ionospheric origin has many influences on reconnection, wave-particle interactions, and space weather effects. We will illustrate the continuity, morphology, and consequences of the geospace plume using observations from the March 2015 great geomagnetic storm. This interval has excellent coverage of the spatial extent and dynamics of the plume in the ionosphere (IS radar and GPS TEC mapping), plasmasphere boundary layer (Millstone Hill ISR, Van Allen Probes), and the magnetopause (THEMIS). Quantification of associated mass flows during the formation and evolution of plume structures is also possible at multiple space and time locations.

Potential fate of SOC eroded from natural crusted soil surface under simulated wind driven storm

NASA Astrophysics Data System (ADS)

Xiao, Liangang; Fister, Wolfgang; Greenwood, Philip; Hu, Yaxian; Kuhn, Nikolaus J.

2016-04-01

Improving the assessment of the impact of soil erosion on carbon (C) cycling requires a better understanding of the redistribution of eroded sediment and associated soil organic carbon (SOC) across agricultural landscapes. Recent studies conducted on dry-sieved aggregates in the laboratory demonstrated that aggregation can profoundly skew SOC redistribution and its subsequent fate by accelerating settling velocities of aggregated sediment compared to mineral grains, which in turn can increase SOC mineralization into greenhouse gases. However, the erodibility of the soil in the field is more variable than in the laboratory due to tillage, crus formation, drying-wetting and freeze-thaw cycles, and biological effects. This study aimed to investigate the potential fate of the SOC eroded from naturally developed soil surface and to compare the observations with those made in the laboratory. Simulated, short, high intensity wind driven storms were conducted on a crusted loam in the field. The sediments were fractionated with a settling tube according to their potential transport distances. The soil mass, SOC concentration and cumulative 80-day CO2 emission of each fraction were identified. The results show: 1) 53% of eroded sediment and 62% of eroded SOC from the natural surface in the field would be deposited across landscapes, which is six times and three times higher compared to that implied by mineral grains, respectively; 2) the preferential deposition of SOC-rich fast-settling sediment potentially releases approximately 50% more CO2 than the same layer of the non-eroded soil; 3) the respiration of the slow-settling fraction that is potentially transported to the aquatic systems was much more active compared to the other fractions and the bulk soil. Our results confirm in general the conclusions drawn from laboratory and thus demonstrate that aggregation can affect the redistribution of sediment associated SOC under field conditions, including an increase in emissions compared to bulk soil. Overall, this confirms that terrestrial SOC redistribution and the mineralization play an important role in erosion induced C cycling, with major uncertainties to be addressed.

Use of Anthropogenic Radioisotopes to Estimate Rates of Soil Redistribution by Wind

USDA-ARS?s Scientific Manuscript database

Wind erosion results in soil degradation and fugitive dust emissions. The temporal and spatial variability of aeolian processes makes local estimates of long-term average erosion costly and time consuming. Atmospheric testing of nuclear weapons during the 1950s and 1960s resulted in previously non...

Changing Labour Markets in Europe: The Role of Institutions and Policies.

ERIC Educational Resources Information Center

Auer, Peter, Ed.

This book contains five papers on the role of institutions in changing labor markets in Europe. "Introduction" (Peter Auer) explores the following topics: institutions and labor market forces; macroeconomic policy; redistribution of working times; equality of opportunity; and industrial relations and social dialogue. "Small-Economy…

Modelling soil-water dynamics in the rootzone of structured and water-repellent soils

NASA Astrophysics Data System (ADS)

Brown, Hamish; Carrick, Sam; Müller, Karin; Thomas, Steve; Sharp, Joanna; Cichota, Rogerio; Holzworth, Dean; Clothier, Brent

2018-04-01

In modelling the hydrology of Earth's critical zone, there are two major challenges. The first is to understand and model the processes of infiltration, runoff, redistribution and root-water uptake in structured soils that exhibit preferential flows through macropore networks. The other challenge is to parametrise and model the impact of ephemeral hydrophobicity of water-repellent soils. Here we have developed a soil-water model, which is based on physical principles, yet possesses simple functionality to enable easier parameterisation, so as to predict soil-water dynamics in structured soils displaying time-varying degrees of hydrophobicity. Our model, WEIRDO (Water Evapotranspiration Infiltration Redistribution Drainage runOff), has been developed in the APSIM Next Generation platform (Agricultural Production Systems sIMulation). The model operates on an hourly time-step. The repository for this open-source code is https://github.com/APSIMInitiative/ApsimX. We have carried out sensitivity tests to show how WEIRDO predicts infiltration, drainage, redistribution, transpiration and soil-water evaporation for three distinctly different soil textures displaying differing hydraulic properties. These three soils were drawn from the UNSODA (Unsaturated SOil hydraulic Database) soils database of the United States Department of Agriculture (USDA). We show how preferential flow process and hydrophobicity determine the spatio-temporal pattern of soil-water dynamics. Finally, we have validated WEIRDO by comparing its predictions against three years of soil-water content measurements made under an irrigated alfalfa (Medicago sativa L.) trial. The results provide validation of the model's ability to simulate soil-water dynamics in structured soils.

Topographic Controls on Soil Carbon Distribution in Iowa Croplands, USA

NASA Astrophysics Data System (ADS)

McCarty, Greg; Li, Xia

2017-04-01

Topography is a key factor affecting soil organic carbon (SOC) redistribution (erosion or deposition) because it influences several hydrological indices including soil moisture dynamics, runoff velocity and acceleration, and flow divergence and convergence. In this study, we examined the relationship between 15 topographic metrics derived from Light Detection and Ranging (Lidar) data and SOC redistribution in agricultural fields. We adopted the fallout 137Cesium (137Cs) technique to estimate SOC redistribution rates across 560 sampling plots in Iowa. Then, using stepwise ordinarily least square regression (SOLSR) and stepwise principle component analysis (SPCA), topography-based SOC models were developed to simulate spatial patterns of SOC content and redistribution. Results suggested that erosion and deposition of topsoil SOC were regulated by topography with SOC gain in lowland areas and SOC loss in sloping areas. Topographic wetness index (TWI) and slope were the most influential variables controlling SOC content and redistribution. The topography-based models exhibited good performances in simulating SOC content and redistribution across two crop sites with intensive samplings. SPCA models had slightly lower coefficients of determination and Nash-Sutcliffe efficiency values compared to SOLSR models at the field scale. However, significantly SPCA outperformed SOLAR in predicting SOC redistribution patterns at the watershed scale. Results of this study suggest that the topography-based SPCA model was more robust for scaling up models to the watershed scale because SPCA models may better represent the landscapes and are less subject to over fitting. This work suggests an improved method to sample and characterize landscapes for better prediction of soil property distribution.

Time series of low-degree geopotential coefficients from SLR data: estimation of Earth's figure axis and LOD variations

NASA Astrophysics Data System (ADS)

Luceri, V.; Sciarretta, C.; Bianco, G.

2012-12-01

The redistribution of the mass within the earth system induces changes in the Earth's gravity field. In particular, the second-degree geopotential coefficients reflect the behaviour of the Earth's inertia tensor of order 2, describing the main mass variations of our planet impacting the EOPs. Thanks to the long record of accurate and continuous laser ranging observations to Lageos and other geodetic satellites, SLR is the only current space technique capable to monitor the long time variability of the Earth's gravity field with adequate accuracy. Time series of low-degree geopotential coefficients are estimated with our analysis of SLR data (spanning more than 25 years) from several geodetic satellites in order to detect trends and periodic variations related to tidal effects and atmospheric/oceanic mass variations. This study is focused on the variations of the second-degree Stokes coefficients related to the Earth's principal figure axis and oblateness: C21, S21 and C20. On the other hand, surface mass load variations induce excitations in the EOPs that are proportional to the same second-degree coefficients. The time series of direct estimates of low degree geopotential and those derived from the EOP excitation functions are compared and presented together with their time and frequency analysis.

Modeled hydraulic redistribution by Helianthus annuus L. matches observed data only after model modification to include nighttime transpiration

NASA Astrophysics Data System (ADS)

Neumann, R. B.; Cardon, Z. G.; Rockwell, F. E.; Teshera-Levye, J.; Zwieniecki, M.; Holbrook, N. M.

2013-12-01

The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical, and ecological consequences of HR depend on the amount of redistributed water, while the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two eco-types of Helianthus annuus L. in split-pot experiments, we examined how well the widely used HR modeling formulation developed by Ryel et al. (2002) could match experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive nighttime transpiration, and though over the last decade it has become more widely recognized that nighttime transpiration occurs in multiple species and many ecosystems, the original Ryel et al. (2002) formulation does not include the effect of nighttime transpiration on HR. We developed and added a representation of nighttime transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and nighttime stomatal behavior changed, both influencing HR.

The desorptivity model of bulk soil-water evaporation

NASA Technical Reports Server (NTRS)

Clapp, R. B.

1983-01-01

Available models of bulk evaporation from a bare-surfaced soil are difficult to apply to field conditions where evaporation is complicated by two main factors: rate-limiting climatic conditions and redistribution of soil moisture following infiltration. Both factors are included in the "desorptivity model', wherein the evaporation rate during the second stage (the soil-limiting stage) of evaporation is related to the desorptivity parameter, A. Analytical approximations for A are presented. The approximations are independent of the surface soil moisture. However, calculations using the approximations indicate that both soil texture and soil moisture content at depth significantly affect A. Because the moisture content at depth decreases in time during redistribution, it follows that the A parameter also changes with time. Consequently, a method to calculate a representative value of A was developed. When applied to field data, the desorptivity model estimated cumulative evaporation well. The model is easy to calculate, but its usefulness is limited because it requires an independent estimate of the time of transition between the first and second stages of evaporation. The model shows that bulk evaporation after the transition to the second stage is largely independent of climatic conditions.

Current redistribution and generation of kinetic energy in the stagnated Z pinch.

PubMed

Ivanov, V V; Anderson, A A; Papp, D; Astanovitskiy, A L; Talbot, B R; Chittenden, J P; Niasse, N

2013-07-01

The structure of magnetic fields was investigated in stagnated wire-array Z pinches using a Faraday rotation diagnostic at the wavelength of 266 nm. The distribution of current in the pinch and trailing material was reconstructed. A significant part of current can switch from the main pinch to the trailing plasma preheated by x-ray radiation of the pinch. Secondary implosions of trailing plasma generate kinetic energy and provide enhanced heating and radiation of plasma at stagnation. Hot spots in wire-array Z pinches also provide enhanced radiation of the Z pinch. A collapse of a single hot spot radiates 1%-3% of x-ray energy of the Z pinch with a total contribution of hot spots of 10%-30%.

How to design a targeted agricultural subsidy system: efficiency or equity?

PubMed

Cong, Rong-Gang; Brady, Mark

2012-01-01

In this paper we appraise current agricultural subsidy policy in the EU. Several sources of its inefficiency are identified: it is inefficient for supporting farmers' incomes or guaranteeing food security, and irrational transfer payments decoupled from actual performance that may be negative for environmental protection, social cohesion, etc. Based on a simplified economic model, we prove that there is "reverse redistribution" in the current tax-subsidy system, which cannot be avoided. To find a possible way to distribute subsidies more efficiently and equitably, several alternative subsidy systems (the pure loan, the harvest tax and the income contingent loan) are presented and examined.

Annual Geocenter Motion from Space Geodesy and Models

NASA Astrophysics Data System (ADS)

Ries, J. C.

2013-12-01

Ideally, the origin of the terrestrial reference frame and the center of mass of the Earth are always coincident. By construction, the origin of the reference frame is coincident with the mean Earth center of mass, averaged over the time span of the satellite laser ranging (SLR) observations used in the reference frame solution, within some level of uncertainty. At shorter time scales, tidal and non-tidal mass variations result in an offset between the origin and geocenter, called geocenter motion. Currently, there is a conventional model for the tidally-coherent diurnal and semi-diurnal geocenter motion, but there is no model for the non-tidal annual variation. This annual motion reflects the largest-scale mass redistribution in the Earth system, so it essential to observe it for a complete description of the total mass transport. Failing to model it can also cause false signals in geodetic products such as sea height observations from satellite altimeters. In this paper, a variety of estimates for the annual geocenter motion are presented based on several different geodetic techniques and models, and a ';consensus' model from SLR is suggested.

Thermally activated creep and fluidization in flowing disordered materials

NASA Astrophysics Data System (ADS)

Merabia, Samy; Detcheverry, François

2016-11-01

When submitted to a constant mechanical load, many materials display power law creep followed by fluidization. A fundamental understanding of these processes is still far from being achieved. Here, we characterize creep and fluidization on the basis of a mesoscopic viscoplastic model that includes thermally activated yielding events and a broad distribution of energy barriers, which may be lowered under the effect of a local deformation. We relate the creep exponent observed before fluidization to the width of barrier distribution and to the specific form of stress redistribution following yielding events. We show that Andrade creep is accompanied by local strain hardening driven by stress redistribution and find that the fluidization time depends exponentially on the applied stress. The simulation results are interpreted in the light of a mean-field analysis, and should help in rationalizing the creep phenomenology in disordered materials.

Assessment of an in-channel redistribution technique for large woody debris management in Locust Creek, Linn County, Missouri

USGS Publications Warehouse

Heimann, David C.

2017-10-24

The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation and Missouri Department of Natural Resources, completed a study to assess a mechanical redistribution technique used for the management of large woody debris (LWD) jams in Locust Creek within Pershing State Park and Fountain Grove Conservation Area, Linn County, Missouri. Extensive LWD jams were treated from 1996 to 2009 using a low-impact technique in which LWD from the jams was redistributed to reopen the channel and to mimic the natural geomorphic process of channel migration and adjustment to an obstruction. The scope of the study included the comparison of selected channel geometry characteristics and bed material particle-size distribution in seven LWD treatment reaches with that of adjacent untreated reaches (unaffected by LWD accumulations) of Locust Creek. A comparison of 1996 and 2015 survey cross sections in treated and untreated reaches and photograph documentation were used to assess channel geomorphic change and the stability of redistributed LWD. The physical characteristics of LWD within jams present in the study reach during 2015–16 also were documented.Based on the general lack of differences in channel metrics between treated and untreated reaches, it can be concluded that the mechanical redistribution technique has been an effective treatment of extensive LWD jams in Locust Creek. Channel alterations, including aggradation, streamflow piracy, and diversions, have resulted in temporal and spatial changes in the Locust Creek channel that may affect future applications of the redistribution technique in Pershing State Park. The redistribution technique was used to effectively manage LWD in Locust Creek at a potentially lower financial cost and reduced environmental disturbance than the complete removal of LWD.A comparison of four channel metrics (bankfull cross-sectional area, channel width, streamflow capacity, and width-depth ratio) for individual treatment reaches with adjacent untreated reaches indicated no statistically significant difference in most comparisons. Where statistically significant differences in channel metrics were determined between individual reaches, the channel metrics in treatment reaches were significantly less than adjacent untreated reaches in some comparisons, and significantly greater than adjacent untreated reaches in others. Without immediate posttreatment cross sections in treated and untreated reaches for comparison, it is impossible to say with certainty that a lack of significant differences in channel metrics is a result of posttreatment channel adjustment or, conversely, that any significant differences that remain are a result of the treatment of LWD.Characteristics of LWD in accumulations sampled within the study area in 2015 indicate that most sampled pieces were in the 1–2 foot diameter size class, the 5–16 foot length class, and the advanced decay class. Most of documented LWD pieces were loose and not buried, about 20 percent on average had a root wad attached, and about 6.5 percent on average were sawn logs. Most of sampled material was less than one-half of the bankfull channel width, indicating it was easily transportable, and the advanced decay class of material entering the study area indicated that it was likely sourced from outside of Pershing State Park.Redistributed LWD associated with treatment seems to be intact in the 1996 treated reaches from direct observation and from inference because there was net channel aggradation between 1996 and 2015 in comparison surveys. The change in channel area resulting from aggradation in time (1996 to 2015) in treated and untreated reaches exceeded the differences in channel characteristics between the treated and untreated channels in 2015 surveys.

Hydraulic Redistribution: A Modeling Perspective

NASA Astrophysics Data System (ADS)

Daly, E.; Verma, P.; Loheide, S. P., III

2014-12-01

Roots play a key role in the soil water balance. They extract and transport water for transpiration, which usually represents the most important soil water loss in vegetated areas, and can redistribute soil water, thereby increasing transpiration rates and enhancing root nutrient uptake. We present here a two-dimensional model capable of describing two key aspects of root water uptake: root water compensation and hydraulic redistribution. Root water compensation is the ability of root systems to respond to the reduction of water uptake from areas of the soil with low soil water potential by increasing the water uptake from the roots in soil parts with higher water potential. Hydraulic redistribution is a passive transfer of water through the root system from areas of the soil with greater water potential to areas with lower water potential. Both mechanisms are driven by gradients of water potential in the soil and the roots. The inclusion of root water compensation and hydraulic redistribution in models can be achieved by describing root water uptake as a function of the difference in water potential between soil and root xylem. We use a model comprising the Richards equation for the water flow in variably saturated soils and the Darcy's equation for the water flow in the xylem. The two equations are coupled via a sink term, which is assumed to be proportional to the difference between soil and xylem water potentials. The model is applied in two case studies to describe vertical and horizontal hydraulic redistribution and the interaction between vegetation with different root depths. In the case of horizontal redistribution, the model is used to reproduce the fluxes of water across the root system of a tree subjected to uneven irrigation. This example can be extended to situations when only part of the root system has access to water, such as vegetation near creeks, trees at the edge of forests, and street trees in urban areas. The second case is inspired by recent agro-ecosystems experiments that combined different vegetation species to increase crop yield. The presence of deep rooted plants (nursing species) near shallow rooted crops (nursed species) enhanced crop growth thanks to vertical and horizontal hydraulic redistribution. The model is able to reproduce the patterns of water redistribution observed in this scenario.

Earth System Data Records of Mass Transport from Time-Variable Gravity Data

NASA Astrophysics Data System (ADS)

Zlotnicki, V.; Talpe, M.; Nerem, R. S.; Landerer, F. W.; Watkins, M. M.

2014-12-01

Satellite measurements of time variable gravity have revolutionized the study of Earth, by measuring the ice losses of Greenland, Antarctica and land glaciers, changes in groundwater including unsustainable losses due to extraction of groundwater, the mass and currents of the oceans and their redistribution during El Niño events, among other findings. Satellite measurements of gravity have been made primarily by four techniques: satellite tracking from land stations using either lasers or Doppler radio systems, satellite positioning by GNSS/GPS, satellite to satellite tracking over distances of a few hundred km using microwaves, and through a gravity gradiometer (radar altimeters also measure the gravity field, but over the oceans only). We discuss the challenges in the measurement of gravity by different instruments, especially time-variable gravity. A special concern is how to bridge a possible gap in time between the end of life of the current GRACE satellite pair, launched in 2002, and a future GRACE Follow-On pair to be launched in 2017. One challenge in combining data from different measurement systems consists of their different spatial and temporal resolutions and the different ways in which they alias short time scale signals. Typically satellite measurements of gravity are expressed in spherical harmonic coefficients (although expansions in terms of 'mascons', the masses of small spherical caps, has certain advantages). Taking advantage of correlations among spherical harmonic coefficients described by empirical orthogonal functions and derived from GRACE data it is possible to localize the otherwise coarse spatial resolution of the laser and Doppler derived gravity models. This presentation discusses the issues facing a climate data record of time variable mass flux using these different data sources, including its validation.

Evaporation-Driven Charge Redistribution and Current Generation for Energy Harvesting Applications

DTIC Science & Technology

2008-12-01

has occurred and the system has a net positive energy gain, ∆Ecycle, as given by equation (5). 2 2 1 outstorecycle VCE =∆ (5) 5.5 Voltage...then the energy gained using the constant charge model can be represented by equation ( 2 ). minmaxminmax )( 2 1 VVCCE −=∆ ( 2 ) 3. DEVICE...evaporation. Evaporation can be the caused by changes in multiple environmental conditions such as: ( 1 ) percent relative humidity, ( 2 ) temperature, (3

Improving the Terrain-Based Parameter for the Assessment of Snow Redistribution in the Col du Lac Blanc Area and Comparisons with TLS Snow Depth Data

NASA Astrophysics Data System (ADS)

Schön, Peter; Prokop, Alexander; Naaim-Bouvet, Florence; Nishimura, Kouichi; Vionnet, Vincent; Guyomarc'h, Gilbert

2014-05-01

Wind and the associated snow drift are dominating factors determining the snow distribution and accumulation in alpine areas, resulting in a high spatial variability of snow depth that is difficult to evaluate and quantify. The terrain-based parameter Sx characterizes the degree of shelter or exposure of a grid point provided by the upwind terrain, without the computational complexity of numerical wind field models. The parameter has shown to qualitatively predict snow redistribution with good reproduction of spatial patterns, but has failed to quantitatively describe the snow redistribution, and correlations with measured snow heights were poor. The objective of our research was to a) identify the sources of poor correlations between predicted and measured snow re-distribution and b) improve the parameters ability to qualitatively and quantitatively describe snow redistribution in our research area, the Col du Lac Blanc in the French Alps. The area is at an elevation of 2700 m and particularly suited for our study due to its constant wind direction and the availability of data from a meteorological station. Our work focused on areas with terrain edges of approximately 10 m height, and we worked with 1-2 m resolution digital terrain and snow surface data. We first compared the results of the terrain-based parameter calculations to measured snow-depths, obtained by high-accuracy terrestrial laser scan measurements. The results were similar to previous studies: The parameter was able to reproduce observed patterns in snow distribution, but regression analyses showed poor correlations between terrain-based parameter and measured snow-depths. We demonstrate how the correlations between measured and calculated snow heights improve if the parameter is calculated based on a snow surface model instead of a digital terrain model. We show how changing the parameter's search distance and how raster re-sampling and raster smoothing improve the results. To improve the parameter's quantitative abilities, we modified the parameter, based on the comparisons with TLS data and the terrain and wind conditions specific to the research site. The modification is in a linear form f(x) = a * Sx, where a is a newly introduced parameter; f(x) yields the estimates for the snow height. We found that the parameter depends on the time period between the compared snow surfaces and the intensity of drifting snow events, which are linked to wind velocities. At the Col du Lac Blanc test side, blowing snow flux is recorded with snow particle counters (SPC). Snow flux is the number of drifting snow particles per time and area. Hence, the SPC provide data about the duration and intensity of drifting snow events, two important factors not accounted for by the terrain parameter Sx. We analyse how the SPC snow flux data can be used to estimate the magnitude of the new variable parameter a. We could improve the parameters' correlations with measured snow heights and its ability to quantitatively describe snow distribution in the Col du Lac Blanc area. We believe that our work is also a prerequisite to further improve the parameter's ability to describe snow redistribution.

The effect of lung deformation on the spatial distribution of pulmonary blood flow.

PubMed

Arai, Tatsuya J; Theilmann, Rebecca J; Sá, Rui Carlos; Villongco, Michael T; Hopkins, Susan R

2016-11-01

Pulmonary perfusion measurement using magnetic resonance imaging combined with deformable image registration enabled us to quantify the change in the spatial distribution of pulmonary perfusion at different lung volumes. The current study elucidated the effects of tidal volume lung inflation [functional residual capacity (FRC) + 500 ml and FRC + 1 litre] on the change in pulmonary perfusion distribution. Changes in hydrostatic pressure distribution as well as transmural pressure distribution due to the change in lung height with tidal volume inflation are probably bigger contributors to the redistribution of pulmonary perfusion than the changes in pulmonary vasculature resistance caused by lung tissue stretch. Tidal volume lung inflation results in structural changes in the pulmonary circulation, potentially affecting pulmonary perfusion. We hypothesized that perfusion is recruited to regions receiving the greatest deformation from a tidal breath, thus ensuring ventilation-perfusion matching. Density-normalized perfusion (DNP) magnetic resonance imaging data were obtained in healthy subjects (n = 7) in the right lung at functional residual capacity (FRC), FRC+500 ml, and FRC+1.0 l. Using deformable image registration, the displacement of a sagittal lung slice acquired at FRC to the larger volumes was calculated. Registered DNP images were normalized by the mean to estimate perfusion redistribution (nDNP). Data were evaluated across gravitational regions (dependent, middle, non-dependent) and by lobes (upper, RUL; middle, RML; lower, RLL). Lung inflation did not alter mean DNP within the slice (P = 0.10). The greatest expansion was seen in the dependent region (P < 0.0001: dependent vs non-dependent, P < 0.0001: dependent vs middle) and RLL (P = 0.0015: RLL vs RUL, P < 0.0001: RLL vs RML). Neither nDNP recruitment to RLL [+500 ml = -0.047(0.145), +1 litre = 0.018(0.096)] nor to dependent lung [+500 ml = -0.058(0.126), +1 litre = -0.023(0.106)] were found. Instead, redistribution was seen in decreased nDNP in the non-dependent [+500 ml = -0.075(0.152), +1 litre = -0.137(0.167)) and increased nDNP in the gravitational middle lung [+500 ml = 0.098(0.058), +1 litre = 0.093(0.081)] (P = 0.01). However, there was no significant lobar redistribution (P < 0.89). Contrary to our hypothesis, based on the comparison between gravitational and lobar perfusion data, perfusion was not redistributed to the regions of the most inflation. This suggests that either changes in hydrostatic pressure or transmural pressure distribution in the gravitational direction are implicated in the redistribution of perfusion away from the non-dependent lung. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

The effect of lung deformation on the spatial distribution of pulmonary blood flow

PubMed Central

Arai, Tatsuya J.; Theilmann, Rebecca J.; Sá, Rui Carlos; Villongco, Michael T.

2016-01-01

Key points Pulmonary perfusion measurement using magnetic resonance imaging combined with deformable image registration enabled us to quantify the change in the spatial distribution of pulmonary perfusion at different lung volumes.The current study elucidated the effects of tidal volume lung inflation [functional residual capacity (FRC) + 500 ml and FRC + 1 litre] on the change in pulmonary perfusion distribution.Changes in hydrostatic pressure distribution as well as transmural pressure distribution due to the change in lung height with tidal volume inflation are probably bigger contributors to the redistribution of pulmonary perfusion than the changes in pulmonary vasculature resistance caused by lung tissue stretch. Abstract Tidal volume lung inflation results in structural changes in the pulmonary circulation, potentially affecting pulmonary perfusion. We hypothesized that perfusion is recruited to regions receiving the greatest deformation from a tidal breath, thus ensuring ventilation–perfusion matching. Density‐normalized perfusion (DNP) magnetic resonance imaging data were obtained in healthy subjects (n = 7) in the right lung at functional residual capacity (FRC), FRC+500 ml, and FRC+1.0 l. Using deformable image registration, the displacement of a sagittal lung slice acquired at FRC to the larger volumes was calculated. Registered DNP images were normalized by the mean to estimate perfusion redistribution (nDNP). Data were evaluated across gravitational regions (dependent, middle, non‐dependent) and by lobes (upper, RUL; middle, RML; lower, RLL). Lung inflation did not alter mean DNP within the slice (P = 0.10). The greatest expansion was seen in the dependent region (P < 0.0001: dependent vs non‐dependent, P < 0.0001: dependent vs middle) and RLL (P = 0.0015: RLL vs RUL, P < 0.0001: RLL vs RML). Neither nDNP recruitment to RLL [+500 ml = −0.047(0.145), +1 litre = 0.018(0.096)] nor to dependent lung [+500 ml = −0.058(0.126), +1 litre = −0.023(0.106)] were found. Instead, redistribution was seen in decreased nDNP in the non‐dependent [+500 ml = −0.075(0.152), +1 litre = −0.137(0.167)) and increased nDNP in the gravitational middle lung [+500 ml = 0.098(0.058), +1 litre = 0.093(0.081)] (P = 0.01). However, there was no significant lobar redistribution (P < 0.89). Contrary to our hypothesis, based on the comparison between gravitational and lobar perfusion data, perfusion was not redistributed to the regions of the most inflation. This suggests that either changes in hydrostatic pressure or transmural pressure distribution in the gravitational direction are implicated in the redistribution of perfusion away from the non‐dependent lung. PMID:27273807

Overview of physics research on the TCV tokamak

NASA Astrophysics Data System (ADS)

Fasoli, A.; TCV Team

2009-10-01

The Tokamak à Configuration Variable (TCV) tokamak is equipped with high-power (4.5 MW), real-time-controllable EC systems and flexible shaping, and plays an important role in fusion research by broadening the parameter range of reactor relevant regimes, by investigating tokamak physics questions and by developing new control tools. Steady-state discharges are achieved, in which the current is entirely self-generated through the bootstrap mechanism, a fundamental ingredient for ITER steady-state operation. The discharge remains quiescent over several current redistribution times, demonstrating that a self-consistent, 'bootstrap-aligned' equilibrium state is possible. Electron internal transport barrier regimes sustained by EC current drive have also been explored. MHD activity is shown to be crucial in scenarios characterized by large and slow oscillations in plasma confinement, which in turn can be modified by small Ohmic current perturbations altering the barrier strength. In studies of the relation between anomalous transport and plasma shape, the observed dependences of the electron thermal diffusivity on triangularity (direct) and collisionality (inverse) are qualitatively reproduced by non-linear gyro-kinetic simulations and shown to be governed by TEM turbulence. Parallel SOL flows are studied for their importance for material migration. Flow profiles are measured using a reciprocating Mach probe by changing from lower to upper single-null diverted equilibria and shifting the plasmas vertically. The dominant, field-direction-dependent Pfirsch-Schlüter component is found to be in good agreement with theoretical predictions. A field-direction-independent component is identified and is consistent with flows generated by transient over-pressure due to ballooning-like interchange turbulence. Initial high-resolution infrared images confirm that ELMs have a filamentary structure, while fast, localized radiation measurements reveal that ELM activity first appears in the X-point region. Real time control techniques are currently being applied to EC multiple independent power supplies and beam launchers, e.g. to control the plasma current in fully non-inductive conditions, and the plasma elongation through current broadening by far-off-axis heating at constant shaping field.

Cognitive ability and the demand for redistribution.

PubMed

Mollerstrom, Johanna; Seim, David

2014-01-01

Empirical research suggests that the cognitively able are politically more influential than the less able, by being more likely to vote and to assume leadership positions. This study asks whether this pattern matters for public policy by investigating what role a person's cognitive ability plays in determining his preferences for redistribution of income among citizens in society. To answer this question, we use a unique Swedish data set that matches responses to a tailor-made questionnaire to administrative tax records and to military enlistment records for men, with the latter containing a measure of cognitive ability. On a scale of 0 to 100 percent redistribution, a one-standard-deviation increase in cognitive ability reduces the willingness to redistribute by 5 percentage points, or by the same amount as a $35,000 increase in mean annual income. We find support for two channels mediating this economically strong and statistically significant relation. First, higher ability is associated with higher income. Second, ability is positively correlated with the view that economic success is the result of effort, rather than luck. Both these factors are, in turn, related to lower demand for redistribution.

Modeling Water Redistribution in a Near-Surface Arid Soil

NASA Astrophysics Data System (ADS)

Luo, Y.; Ghezzehei, T. A.; Berli, M.; Dijkema, J.; Koonce, J.

2017-12-01

Desert soils cover about one third of the Earth's land surface and play an important role in the ecology and hydrology of arid environments. Despite their large extend, relatively little is known about their near-surface (top centimeters to meter) water dynamics. Recent studies by Koonce (2016) and Dijkema et al. (2017) shed light on the water dynamics of near-surface arid soil but also revealed some of the challenges to simulate the water redistribution in arid soils. The goal of this study was to improve water redistribution simulations in near-surface arid soils by employing more advanced hydraulic conductivity functions. Expanding on the work by Dijkema et al. (2017), we used a HYDRUS-1D model with different hydraulic conductivity functions to simulate water redistribution within the soil as a function of precipitation, evaporation and drainage. Model calculations were compared with measured data from the SEPHAS weighing lysimeters in Boulder City, NV. Preliminary results indicate that water redistribution simulations of near-surface arid soils can be improved by using hydraulic conductivity functions that can capture capillary, film and vapor flow, like for example the Peter-Durner-Iden (PDI) model.

Cognitive Ability and the Demand for Redistribution

PubMed Central

Mollerstrom, Johanna; Seim, David

2014-01-01

Empirical research suggests that the cognitively able are politically more influential than the less able, by being more likely to vote and to assume leadership positions. This study asks whether this pattern matters for public policy by investigating what role a person's cognitive ability plays in determining his preferences for redistribution of income among citizens in society. To answer this question, we use a unique Swedish data set that matches responses to a tailor-made questionnaire to administrative tax records and to military enlistment records for men, with the latter containing a measure of cognitive ability. On a scale of 0 to 100 percent redistribution, a one-standard-deviation increase in cognitive ability reduces the willingness to redistribute by 5 percentage points, or by the same amount as a $35,000 increase in mean annual income. We find support for two channels mediating this economically strong and statistically significant relation. First, higher ability is associated with higher income. Second, ability is positively correlated with the view that economic success is the result of effort, rather than luck. Both these factors are, in turn, related to lower demand for redistribution. PMID:25343713

Scan-rate-dependent current rectification of cone-shaped silica nanopores in quartz nanopipettes.

PubMed

Guerrette, Joshua P; Zhang, Bo

2010-12-08

Here we report the voltammetric behavior of cone-shaped silica nanopores in quartz nanopipettes in aqueous solutions as a function of the scan rate, v. Current rectification behavior for silica nanopores with diameters in the range 4-25 nm was studied. The rectification behavior was found to be strongly dependent on the scan rate. At low scan rates (e.g., v < 1 V/s), the rectification ratio was found to be at its maximum and relatively independent of v. At high scan rates (e.g., v > 200 V/s), a nearly linear current-voltage response was obtained. In addition, the initial voltage was shown to play a critical role in the current-voltage response of cone-shaped nanopores at high scan rates. We explain this v-dependent current-voltage response by ionic redistribution in the vicinity of the nanopore mouth.

Short-Term Changes in Physical and Chemical Properties of Soil Charcoal Support Enhanced Landscape Mobility

NASA Astrophysics Data System (ADS)

Pyle, Lacey A.; Magee, Kate L.; Gallagher, Morgan E.; Hockaday, William C.; Masiello, Caroline A.

2017-11-01

Charcoal is a major component of the stable soil organic carbon reservoir, and the physical and chemical properties of charcoal can sometimes significantly alter bulk soil properties (e.g., by increasing soil water holding capacity). However, our understanding of the residence time of soil charcoal remains uncertain, with old measured soil charcoal ages in apparent conflict with relatively short modeled and measured residence times. These discrepancies may exist because the fate of charcoal on the landscape is a function not just of its resistance to biological decomposition but also its physical mobility. Mobility may be important in controlling charcoal landscape residence time and may artificially inflate estimates of its degradability, but few studies have examined charcoal vulnerability to physical redistribution. Charcoal landscape redistribution is likely higher than other organic carbon fractions owing to charcoal's low bulk density, typically less than 1.0 g/cm3. Here we examine both the physical and chemical properties of soil and charcoal over a period of two years following a 2011 wildfire in Texas. We find little change in properties with time; however, we find evidence of enhanced mobility of charcoal relative to other forms of soil organic matter. These data add to a growing body of evidence that charcoal is preferentially eroded, offering another explanation for variations observed in its environmental residence times.

Time-Resolved Chemical Mapping in Light-Emitting Electrochemical Cells.

PubMed

Jafari, Mohammad Javad; Liu, Jiang; Engquist, Isak; Ederth, Thomas

2017-01-25

An understanding of the doping and ion distributions in light-emitting electrochemical cells (LECs) is required to approach a realistic conduction model which can precisely explain the electrochemical reactions, p-n junction formation, and ion dynamics in the active layer and to provide relevant information about LECs for systematic improvement of function and manufacture. Here, Fourier-transform infrared (FTIR) microscopy is used to monitor anion density profile and polymer structure in situ and for time-resolved mapping of electrochemical doping in an LEC under bias. The results are in very good agreement with the electrochemical doping model with respect to ion redistribution and formation of a dynamic p-n junction in the active layer. We also physically slow ions by decreasing the working temperature and study frozen-junction formation and immobilization of ions in a fixed-junction LEC device by FTIR imaging. The obtained results show irreversibility of the ion redistribution and polymer doping in a fixed-junction device. In addition, we demonstrate that infrared microscopy is a useful tool for in situ characterization of electroactive organic materials.

Sources of inflow and nature of redistribution of 90Sr in the salt lakes of the Crimea.

PubMed

Mirzoyeva, N Yu; Arkhipova, S I; Kravchenko, N V

2018-08-01

At the first time for the period after the Chernobyl NPP accident the nature of the redistribution of the 90 Sr concentrations in components of the ecosystems of the salt lakes of the Crimea were identified and described. Concentration of 90 Sr in water of the salt lakes depends on the sources of the inflow this radionuclide into aquatic ecosystems and salinity level of lakes water. Until April 2014 the flow of the Dnieper river water through the Northern-Crimean canal was more important factor of contamination of salt lakes of the Crimea by 90 Sr, than atmospheric fallout of this radionuclide after the Chernobyl NPP accident. Concentrations of 90 Sr in water of the salt lakes of the Crimea exceeded 2.4-156.5 times its concentrations in their bottom sediments. The 90 Sr dose commitments to hydrophytes, which were sampled from the salt lakes of the Crimea have not reached values which could impact them during entire the after-accident period. Copyright © 2017 Elsevier Ltd. All rights reserved.

In-silico studies of neutral drift for functional protein interaction networks

NASA Astrophysics Data System (ADS)

Ali, Md Zulfikar; Wingreen, Ned S.; Mukhopadhyay, Ranjan

We have developed a minimal physically-motivated model of protein-protein interaction networks. Our system consists of two classes of enzymes, activators (e.g. kinases) and deactivators (e.g. phosphatases), and the enzyme-mediated activation/deactivation rates are determined by sequence-dependent binding strengths between enzymes and their targets. The network is evolved by introducing random point mutations in the binding sequences where we assume that each new mutation is either fixed or entirely lost. We apply this model to studies of neutral drift in networks that yield oscillatory dynamics, where we start, for example, with a relatively simple network and allow it to evolve by adding nodes and connections while requiring that dynamics be conserved. Our studies demonstrate both the importance of employing a sequence-based evolutionary scheme and the relative rapidity (in evolutionary time) for the redistribution of function over new nodes via neutral drift. Surprisingly, in addition to this redistribution time we discovered another much slower timescale for network evolution, reflecting hidden order in sequence space that we interpret in terms of sparsely connected domains.

Stereological analysis of gravitropism in protonemata of the moss Ceratodon

NASA Technical Reports Server (NTRS)

Walker, L. M.; Sack, F. D.

1997-01-01

Apical cells of dark-grown protonemata of the moss Cerotodon purpureus are negatively gravitropic. Previous light microscopy has shown that reorientation to the horizontal induces amyloplast sedimentation and redistribution of microtubules. To determine whether other components become redistributed laterally or axially, the apical 35 micrometers of both vertical and horizontal apical cells were compared stereologically using transmission electron microscopy. Reorientation to the horizontal changed the longitudinal distributions of tubular ER, Golgi stacks, and vesicles but not cisternal ER, mitochondria, and plastids. Only plastids showed a statistically significant lateral redistribution after horizontal placement. Qualitative examination of the sedimentation zone showed plastids sedimented close to peripherally located ER with vacuoles displaced above plastids. These results argue against a model where differential tip growth results from a redistribution of Golgi stacks or exocytic vesicles.

The Deserving Poor, the Family, and the U.S. Welfare System

PubMed Central

Moffitt, Robert A.

2015-01-01

Contrary to the popular view that the U.S. welfare system has been in a contractionary phase after the expansions of the welfare state in the 1960s, welfare spending resumed steady growth after a pause in the 1970s. However, while aggregate spending is higher than ever, there has been a redistribution away from non-elderly and non-disabled families to families with older adults and to families with recipients of disability programs, a redistribution away from non-elderly nondisabled single parent families to married parent families, and a redistribution of transfers away from the poorest families to those with higher incomes. These redistributions likely reflect long-standing, and perhaps increasing, conceptualizations by U.S. society of which poor are deserving and which are not. PMID:26047935

A mass-balance model to separate and quantify colloidal and solute redistributions in soil

USGS Publications Warehouse

Bern, C.R.; Chadwick, O.A.; Hartshorn, A.S.; Khomo, L.M.; Chorover, J.

2011-01-01

Studies of weathering and pedogenesis have long used calculations based upon low solubility index elements to determine mass gains and losses in open systems. One of the questions currently unanswered in these settings is the degree to which mass is transferred in solution (solutes) versus suspension (colloids). Here we show that differential mobility of the low solubility, high field strength (HFS) elements Ti and Zr can trace colloidal redistribution, and we present a model for distinguishing between mass transfer in suspension and solution. The model is tested on a well-differentiated granitic catena located in Kruger National Park, South Africa. Ti and Zr ratios from parent material, soil and colloidal material are substituted into a mixing equation to quantify colloidal movement. The results show zones of both colloid removal and augmentation along the catena. Colloidal losses of 110kgm-2 (-5% relative to parent material) are calculated for one eluviated soil profile. A downslope illuviated profile has gained 169kgm-2 (10%) colloidal material. Elemental losses by mobilization in true solution are ubiquitous across the catena, even in zones of colloidal accumulation, and range from 1418kgm-2 (-46%) for an eluviated profile to 195kgm-2 (-23%) at the bottom of the catena. Quantification of simultaneous mass transfers in solution and suspension provide greater specificity on processes within soils and across hillslopes. Additionally, because colloids include both HFS and other elements, the ability to quantify their redistribution has implications for standard calculations of soil mass balances using such index elements. ?? 2011.

Plutonium in the atmosphere: A global perspective.

PubMed

Thakur, P; Khaing, H; Salminen-Paatero, S

2017-09-01

A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes ( 239+240 Pu and 238 Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that 239+240 Pu concentration post-1984 is still frequently detectable, whereas 238 Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

High Frequency Chandler Wobble Excitation

NASA Astrophysics Data System (ADS)

Seitz, F.; Stuck, J.; Thomas, M.

2003-04-01

Variations of Earth rotation on sub-daily to secular timescales are caused by mass redistributions in the Earth system as a consequence of geophysical processes and gravitational influences. Forced oscillations of polar motion are superposed by free oscillations of the Earth, i.e. the Chandler wobble and the free core nutation. In order to study the interactions between externally induced polar motion and the Earth's free oscillations, a non-linear gyroscopic model has been developed. In most of the former investigations on polar motion, the Chandler wobble is introduced as a damped oscillation with predetermined frequency and amplitude. However, as the effect of rotational deformation is a backcoupling mechanism of polar motion on the Earth's rotational dynamics, both period and amplitude of the Chandler wobble are time-dependent when regarding additional excitations from, e.g., atmospheric or oceanic mass redistributions. The gyroscopic model is free of any explicit information concerning amplitude, phase, and period of free oscillations. The characteristics of the Earth's free oscillation is reproduced by the model from rheological and geometrical parameters and rotational deformation is taken into account. This enables to study the time variable Chandler oscillation when the gyro is forced with atmospheric and oceanic angular momentum from the global atmospheric ECHAM3-T21 general circulation model together with the ocean model for circulation and tides OMCT driven by ECHAM including surface pressure. Besides, mass redistributions in the Earth's body due to gravitational and loading deformations are regarded and external torques exerted by Moon and Sun are considered. The numerical results of the gyro are significantly related with the geodetically observed time series of polar motion published by the IERS. It is shown that the consistent excitation is capable to counteract the damping and thus to maintain the Chandler amplitude. Spectral analyses of the ECHAM and OMCT forcing fields give no hint for increased excitation power in the Chandler band. Thus it is assumed, that continuous high frequency excitation due to stochastic weather phenomena is responsible for the perpetuation of the Chandler wobble.

Portable gamma spectrometry: measuring soil erosion in-situ at four Critical Zone Observatories in P. R. China

NASA Astrophysics Data System (ADS)

Sanderson, N. K.; Green, S. M.; Chen, Z.; Wang, J.; Wang, Y.; Wang, R.; Yu, K.; Tu, C.; Jia, X.; Li, G.; Peng, X.; Quine, T. A.

2017-12-01

Detecting patterns of soil erosion, redistribution, and/soil nutrient loss is important for long-term soil conservation and agricultural sustainability. Caesium-137 (137Cs) and other fallout radionuclide inventories have been used over the the last 50 years to track soil erosion, transport and deposition on a catchment scale, and have been shown to be useful for informing models of temporal/spatial soil redistribution. Traditional sampling methods usually involves coring, grinding, sieving, sub-sampling and laboratory analysis using HPGe detectors, all of which can be costly and time consuming. In-situ measurements can provide a mechanism for assessment of 137Cs over larger areas that integrate the spatial variability, and expand turnover of analyses. Here, we assess the applicability of an in-situ approach based on radionuclide principles, and provide a comparison of the two approaches: laboratory vs. in-situ. The UK-China Critical Zone Observatory (CZO) programme provides an ideal research platform to assess the in-situ approach to measuring soil erosion: using a portable gamma spectrometer to determine 137Cs inventories. Four extensive field slope surveys were conducted in the CZO's, which covers four ecosystem types in China: karst, red soil, peri-urban, and loess plateau. In each CZO, 3-6 plots were measured along 2 slope transects, with 3 replicated 1 hour counts of 137Cs in each plot. In addition, 137Cs soil depth and bulk density profiles were also sampled for each plot, and lab-derived inventories calculated using traditional methods for comparison. Accurately and rapidly measuring 137Cs inventories using a portable field detector allows for a greater coverage of sampling locations and the potential for small-scale spatial integration, as well as the ability to re-visit sites over time and continually adapt and improve soil erosion/redistribution models, thus more effectively targeting areas of interest with reduced cost and time constraints.

Topographic Metric Predictions of Soil redistribution and Organic Carbon Distribution in Croplands

NASA Astrophysics Data System (ADS)

Mccarty, G.; Li, X.

2017-12-01

Landscape topography is a key factor controlling soil redistribution and soil organic carbon (SOC) distribution in Iowa croplands (USA). In this study, we adopted a combined approach based on carbon () and cesium (137Cs) isotope tracers, and digital terrain analysis to understand patterns of SOC redistribution and carbon sequestration dynamics as influenced by landscape topography in tilled cropland under long term corn/soybean management. The fallout radionuclide 137Cs was used to estimate soil redistribution rates and a Lidar-derived DEM was used to obtain a set of topographic metrics for digital terrain analysis. Soil redistribution rates and patterns of SOC distribution were examined across 560 sampling locations at two field sites as well as at larger scale within the watershed. We used δ13C content in SOC to partition C3 and C4 plant derived C density at 127 locations in one of the two field sites with corn being the primary source of C4 C. Topography-based models were developed to simulate SOC distribution and soil redistribution using stepwise ordinary least square regression (SOLSR) and stepwise principal component regression (SPCR). All topography-based models developed through SPCR and SOLSR demonstrated good simulation performance, explaining more than 62% variability in SOC density and soil redistribution rates across two field sites with intensive samplings. However, the SOLSR models showed lower reliability than the SPCR models in predicting SOC density at the watershed scale. Spatial patterns of C3-derived SOC density were highly related to those of SOC density. Topographic metrics exerted substantial influence on C3-derived SOC density with the SPCR model accounting for 76.5% of the spatial variance. In contrast C4 derived SOC density had poor spatial structure likely reflecting the substantial contribution of corn vegetation to recently sequestered SOC density. Results of this study highlighted the utility of topographic SPCR models for scaling field measurements of SOC density and soil redistribution rates to watershed scale which will allow watershed model to better predict fate of ecosystem C on agricultural landscapes.

Redistribution of boron in leaves reduces boron toxicity.

PubMed

Reid, Robert J; Fitzpatrick, Kate L

2009-11-01

High soil boron (B) concentrations lead to the accumulation of B in leaves, causing the development of necrotic regions in leaf tips and margins, gradually extending back along the leaf. Plants vary considerably in their tolerance to B toxicity, and it was recently discovered that one of the tolerance mechanisms involved extrusion of B from the root. Expression of a gene encoding a root B efflux transporter was shown to be much higher in tolerant cultivars. In our current research we have shown that the same gene is also upregulated in leaves. However, unlike in the root, the increased activity of the B efflux transporter in the leaves cannot reduce the tissue B concentration. Instead, we have shown that in tolerant cultivars, these transporters redistribute B from the intracellular phase where it is toxic, into the apoplast which is much less sensitive to B. These results provide an explanation of why different cultivars with the same leaf B concentrations can show markedly different toxicity symptoms. We have also shown that rain can remove a large proportion of leaf B, leading to significant improvements of growth of both leaves and roots.

Xylem- and phloem-based transport of CuO nanoparticles in maize (Zea mays L.).

PubMed

Wang, Zhenyu; Xie, Xiaoyan; Zhao, Jian; Liu, Xiaoyun; Feng, Wenqiang; White, Jason C; Xing, Baoshan

2012-04-17

This work reports on the toxicity of CuO nanoparticles (NPs) to maize (Zea mays L.) and their transport and redistribution in the plant. CuO NPs (100 mg L(-1)) had no effect on germination, but inhibited the growth of maize seedlings; in comparison the dissolved Cu(2+) ions and CuO bulk particles had no obvious effect on maize growth. CuO NPs were present in xylem sap as examined by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), showing that CuO NPs were transported from roots to shoots via xylem. Split-root experiments and high-resolution TEM observation further showed that CuO NPs could translocate from shoots back to roots via phloem. During this translocation, CuO NPs could be reduced from Cu (II) to Cu (I). To our knowledge, this is the first report of root-shoot-root redistribution of CuO NPs within maize. The current study provides direct evidence for the bioaccumulation and biotransformation of CuO NPs (20-40 nm) in maize, which has significant implications on the potential risk of NPs and food safety.

Time-resolved generation of membrane potential by ba3 cytochrome c oxidase from Thermus thermophilus coupled to single electron injection into the O and OH states.

PubMed

Siletsky, Sergey A; Belevich, Ilya; Belevich, Nikolai P; Soulimane, Tewfik; Wikström, Mårten

2017-11-01

Two electrogenic phases with characteristic times of ~14μs and ~290μs are resolved in the kinetics of membrane potential generation coupled to single-electron reduction of the oxidized "relaxed" O state of ba 3 oxidase from T. thermophilus (O→E transition). The rapid phase reflects electron redistribution between Cu A and heme b. The slow phase includes electron redistribution from both Cu A and heme b to heme a 3 , and electrogenic proton transfer coupled to reduction of heme a 3 . The distance of proton translocation corresponds to uptake of a proton from the inner water phase into the binuclear center where heme a 3 is reduced, but there is no proton pumping and no reduction of Cu B . Single-electron reduction of the oxidized "unrelaxed" state (O H →E H transition) is accompanied by electrogenic reduction of the heme b/heme a 3 pair by Cu A in a "fast" phase (~22μs) and transfer of protons in "middle" and "slow" electrogenic phases (~0.185ms and ~0.78ms) coupled to electron redistribution from the heme b/heme a 3 pair to the Cu B site. The "middle" and "slow" electrogenic phases seem to be associated with transfer of protons to the proton-loading site (PLS) of the proton pump, but when all injected electrons reach Cu B the electronic charge appears to be compensated by back-leakage of the protons from the PLS into the binuclear site. Thus proton pumping occurs only to the extent of ~0.1 H + /e - , probably due to the formed membrane potential in the experiment. Copyright © 2017 Elsevier B.V. All rights reserved.

Estimating Temporal Redistribution of Surface Melt Water into Upper Stratigraphy of the Juneau Icefield, Alaska

NASA Astrophysics Data System (ADS)

Wilner, J.; Smith, B.; Moore, T.; Campbell, S. W.; Slavin, B. V.; Hollander, J.; Wolf, J.

2015-12-01

The redistribution of winter accumulation from surface melt into firn or deeper layers (i.e. internal accumulation) remains a poorly understood component of glacier mass balance. Winter accumulation is usually quantified prior to summer melt, however the time window between accumulation and the onset of melt is minimal so this is not always possible. Studies which are initiated following the onset of summer melt either neglect sources of internal accumulation or attempt to estimate melt (and therefore winter accumulation uncertainty) through a variety of modeling methods. Here, we used ground-penetrating radar (GPR) repeat common midpoint (CMP) surveys with supporting common offset surveys, mass balance snow pits, and probing to estimate temporal changes in water content within the winter accumulation and firn layers of the southern Juneau Icefield, Alaska. In temperate glaciers, radio-wave velocity is primarily dependent on water content and snow or firn density. We assume density changes are temporally slow relative to water flow through the snow and firn pack, and therefore infer that changing radio-wave velocities measured by successive CMP surveys result from flux in surface melt through deeper layers. Preliminary CMP data yield radio-wave velocities of 0.15 to 0.2 m/ns in snowpack densities averaging 0.56 g cm-3, indicating partially to fully saturated snowpack (4-9% water content). Further spatial-temporal analysis of CMP surveys is being conducted. We recommend that repeat CMP surveys be conducted over a longer time frame to estimate stratigraphic water redistribution between the end of winter accumulation and maximum melt season. This information could be incorporated into surface energy balance models to further understanding of the influence of internal accumulation on glacier mass balance.

Settling Velocity Specific SOC Distribution along Hillslopes - A field investigation in Denmark

NASA Astrophysics Data System (ADS)

Kuhn, N. J.; Hu, Y.

2015-12-01

The net effects of soil erosion by water, as a sink or source of atmospheric CO2, are decisively affected by the spatial re-distribution and stability of eroded soil organic carbon (SOC). The deposition position of eroded SOC, into terrestrial or aquatic systems, is actually decided by the transport distances of soil fractions where the SOC is stored. In theory, the transport distances of aggregated soil fractions are related to their settling velocities under given layer conditions. Yet, little field investigation has been conducted to examine the actual movement of eroded soil fractions along hillslopes, let alone the re-distribution pattern of functional SOC fractions. Eroding sandy soils and sediment were sampled after a series of rainfall events from different topographic positions along a slope on a freshly seeded cropland in Jutland, Denmark. All the soil samples from difference topographic positions along the slope were fractionated into five settling classes using a settling tube apparatus. The SOC content, 13C signature, and C:N ratios of all settling fractions were measured. Our results show that: 1) the spatial distribution of soil settling classes along the slope clearly shows a coarsening effect at the deposition area immediately below the eroding slope, followed by a fining trend on the deposition area at the slope tail. This proves the validity of the conceptual model in Starr et al. 2000 to predict SOC redistribution patterns along eroding hillslopes. 2) The isotopically enriched 13C on the slope back suggests greater decomposition rates possibly experienced by eroded SOC during transport, while the pronounced respiration rates at the slope tail indicate a great potential of CO2 emissions after deposition. Overall, our results illustrate that immediate deposition of fast settling soil fractions, and the thus induced preferential deposition of SOC at foot slope and potential CO2 emissions during transport, must be appropriately accounted for in current soil carbon balances. To achieve this, a SOC erodibility parameter based on the actual settling velocity distribution of eroded fractions (aggregated or not aggregated) is urgently needed to better parameterize soil erosion models with respect to SOC spatial redistribution.

Hall-MHD and PIC Modeling of the Conduction-to-Opening Transition in a Plasma Opening Switch

NASA Astrophysics Data System (ADS)

Schumer, J. W.; SwanekampDdagger, S. B.; Ottinger, P. F.; Commisso, R. J.; Weber, B. V.

1998-11-01

Utilizing the fast opening characteristics of a plasma opening switch (POS), inductive energy storage devices can generate short-duration high-power pulses (<0.1 μ s, >1 TW) with current rise-times on the order of 10 ns. Plasma redistribution and thinning during the POS conduction phase can be modeled adequately with MHD methods. By including the Hall term in Ohm's Law, MHD methods can simulate plasmas with density gradient scale lengths between c/ω_pe < Ln < c/ω_pi. However, the neglect of electron inertia (c/ω_pe) and space-charge separation (λ_De) by single-fluid theory eventually becomes invalid in small gap regions that form during POS opening. PIC methods are well-suited for low-density plasmas, but are numerically taxed by high-density POS regions. An interface converts MHD (Mach2) output into PIC (Magic) input suitable for validating various transition criteria through comparison of current and density distributions from both methods. We will discuss recent progress in interfacing Hall-MHD and PIC simulations. Work supported by Defense Special Weapons Agency. ^ NRL-NRC Research Associate. hspace0.25in ^ JAYCOR, Vienna, VA 22102.

Disruption of Transcriptional Coactivator Sub1 Leads to Genome-Wide Re-distribution of Clustered Mutations Induced by APOBEC in Active Yeast Genes

PubMed Central

Dhar, Alok; Polev, Dmitrii E.; Masharsky, Alexey E.; Rogozin, Igor B.; Pavlov, Youri I.

2015-01-01

Mutations in genomes of species are frequently distributed non-randomly, resulting in mutation clusters, including recently discovered kataegis in tumors. DNA editing deaminases play the prominent role in the etiology of these mutations. To gain insight into the enigmatic mechanisms of localized hypermutagenesis that lead to cluster formation, we analyzed the mutational single nucleotide variations (SNV) data obtained by whole-genome sequencing of drug-resistant mutants induced in yeast diploids by AID/APOBEC deaminase and base analog 6-HAP. Deaminase from sea lamprey, PmCDA1, induced robust clusters, while 6-HAP induced a few weak ones. We found that PmCDA1, AID, and APOBEC1 deaminases preferentially mutate the beginning of the actively transcribed genes. Inactivation of transcription initiation factor Sub1 strongly reduced deaminase-induced can1 mutation frequency, but, surprisingly, did not decrease the total SNV load in genomes. However, the SNVs in the genomes of the sub1 clones were re-distributed, and the effect of mutation clustering in the regions of transcription initiation was even more pronounced. At the same time, the mutation density in the protein-coding regions was reduced, resulting in the decrease of phenotypically detected mutants. We propose that the induction of clustered mutations by deaminases involves: a) the exposure of ssDNA strands during transcription and loss of protection of ssDNA due to the depletion of ssDNA-binding proteins, such as Sub1, and b) attainment of conditions favorable for APOBEC action in subpopulation of cells, leading to enzymatic deamination within the currently expressed genes. This model is applicable to both the initial and the later stages of oncogenic transformation and explains variations in the distribution of mutations and kataegis events in different tumor cells. PMID:25941824

Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

NASA Astrophysics Data System (ADS)

Fu, Congsheng; Wang, Guiling; Goulden, Michael L.; Scott, Russell L.; Bible, Kenneth; Cardon, Zoe G.

2016-05-01

Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site comparisons for contrasting climate regimes and multiple vegetation types via the integration of measurement and modeling. Here, we incorporated the HR scheme of Ryel et al. (2002) into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture the magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on land surface water and energy budgets, and to explore how the impact may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites with contrasting climate regimes and multiple vegetation types were studied, including the Wind River Crane site in Washington State, the Santa Rita Mesquite savanna site in southern Arizona, and six sites along the Southern California Climate Gradient. HR flux, evapotranspiration (ET), and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement matches of evapotranspiration, Bowen ratio, and soil moisture particularly during dry seasons. Our results also reveal that HR has important hydrological impact in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.

Controls on the global distribution of contourite drifts: Insights from an eddy-resolving ocean model

NASA Astrophysics Data System (ADS)

Thran, Amanda C.; Dutkiewicz, Adriana; Spence, Paul; Müller, R. Dietmar

2018-05-01

Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a global scale. Using an eddy-resolving ocean model and a new georeferenced database of 267 contourites, we show that the global distribution of modern contourite drifts strongly depends on the configuration of the world's most powerful bottom currents, many of which are associated with global meridional overturning circulation. Bathymetric obstacles frequently modify flow direction and intensity, imposing additional finer-scale control on drift occurrence. Mean bottom current speed over contourite-covered areas is only slightly higher (2.2 cm/s) than the rest of the global ocean (1.1 cm/s), falling below proposed thresholds deemed necessary to re-suspend and redistribute sediments (10-15 cm/s). However, currents fluctuate more frequently and intensely over areas with drifts, highlighting the role of intermittent, high-energy bottom current events in sediment erosion, transport, and subsequent drift accumulation. We identify eddies as a major driver of these bottom current fluctuations, and we find that simulated bottom eddy kinetic energy is over three times higher in contourite-covered areas in comparison to the rest of the ocean. Our work supports previous hypotheses which suggest that contourite deposition predominantly occurs due to repeated acute events as opposed to continuous reworking under average-intensity background flow conditions. This suggests that the contourite record should be interpreted in terms of a bottom current's susceptibility to experiencing periodic, high-speed current events. Our results also highlight the potential role of upper ocean dynamics in contourite sedimentation through its direct influence on deep eddy circulation.

Nutrient Pumping/Advection by Propagating Rossby Waves in the Kuroshio Extension

DTIC Science & Technology

2010-01-01

sea-elevation changes or SLA variance levels are a maximum as eddies and meanders cross a mean route. This boundary in terms of Chl- a levels (lower...and elevated Chl- a levels ) is south of the KE jet. Kuroshio Extension meanders and rings carry different water types across a mean Kuroshio Extension...Fig. 5A). The ring or eddy currents may also redistribute the surface Chl- a levels , drawing out plumes of locally increased Chl-a from regions of

Exposure to inequality affects support for redistribution.

PubMed

Sands, Melissa L

2017-01-24

The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals' support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a "millionaire's tax." Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals' willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject.

Master equation theory applied to the redistribution of polarized radiation in the weak radiation field limit. V. The two-term atom

NASA Astrophysics Data System (ADS)

Bommier, Véronique

2017-11-01

Context. In previous papers of this series, we presented a formalism able to account for both statistical equilibrium of a multilevel atom and coherent and incoherent scatterings (partial redistribution). Aims: This paper provides theoretical expressions of the redistribution function for the two-term atom. This redistribution function includes both coherent (RII) and incoherent (RIII) scattering contributions with their branching ratios. Methods: The expressions were derived by applying the formalism outlined above. The statistical equilibrium equation for the atomic density matrix is first formally solved in the case of the two-term atom with unpolarized and infinitely sharp lower levels. Then the redistribution function is derived by substituting this solution for the expression of the emissivity. Results: Expressions are provided for both magnetic and non-magnetic cases. Atomic fine structure is taken into account. Expressions are also separately provided under zero and non-zero hyperfine structure. Conclusions: Redistribution functions are widely used in radiative transfer codes. In our formulation, collisional transitions between Zeeman sublevels within an atomic level (depolarizing collisions effect) are taken into account when possible (I.e., in the non-magnetic case). However, the need for a formal solution of the statistical equilibrium as a preliminary step prevents us from taking into account collisional transfers between the levels of the upper term. Accounting for these collisional transfers could be done via a numerical solution of the statistical equilibrium equation system.

Myocardial viability assessment after acute myocardial infarction: low-dose dobutamine echocardiography versus rest-redistribution thallium-201 SPECT.

PubMed

Castini, D; Bestetti, A; Garbin, M; Di Leo, C; Bigi, R; Sponzilli, C; Concardi, G; Gioventù, M; Tarolo, G L; Lombardi, F; Fiorentini, C

1999-09-01

The presence of tissue viability is of great importance in the prognostic work-up of patients recovering from acute myocardial infarction. However, uncertainty still exists concerning the optimal tool for its assessment. The present study was undertaken in order to compare low-dose dobutamine echocardiography and rest-redistribution thallium SPECT for predicting late improvement of regional left ventricular function after acute myocardial infarction. Fifteen patients undergoing coronary angiography, low-dose dobutamine echocardiography and rest-redistribution thallium SPECT after thrombolyzed anterior acute myocardial infarction were studied. A 3 month follow-up echocardiogram was performed in all patients and 9 underwent coronary revascularization. A significant (> or = 70%) residual stenosis of the infarct-related artery was present in 14 patients, whilst a total occlusion was observed in 1. At 3 month follow-up, 41% of the dyssynergic segments improved. The sensitivity, specificity and accuracy for late wall motion improvement was 61, 89 and 77% for low-dose dobutamine echocardiography and, respectively, 76, 45 and 58% for rest-redistribution thallium SPECT. Tissue viability was detected in 65 and 31% of dyssynergic segments by rest-redistribution thallium SPECT and low-dose dobutamine echocardiography, respectively (p < 0.001). The agreement between the two techniques was 48%. Low-dose dobutamine echocardiography is more accurate than rest-redistribution thallium SPECT for predicting 3 month wall motion improvement in patients with acute anterior myocardial infarction, mainly due to its significantly better specificity.

Finite Element Analysis of Magnetic Damping Effects on G-Jitter Induced Fluid Flow

NASA Technical Reports Server (NTRS)

Pan, Bo; Li, Ben Q.; deGroh, Henry C., III

1997-01-01

This paper reports some interim results on numerical modeling and analyses of magnetic damping of g-jitter driven fluid flow in microgravity. A finite element model is developed to represent the fluid flow, thermal and solute transport phenomena in a 2-D cavity under g-jitter conditions with and without an applied magnetic field. The numerical model is checked by comparing with analytical solutions obtained for a simple parallel plate channel flow driven by g-jitter in a transverse magnetic field. The model is then applied to study the effect of steady state g-jitter induced oscillation and on the solute redistribution in the liquid that bears direct relevance to the Bridgman-Stockbarger single crystal growth processes. A selection of computed results is presented and the results indicate that an applied magnetic field can effectively damp the velocity caused by g-jitter and help to reduce the time variation of solute redistribution.

Simulation of ozone production in a complex circulation region using nested grids

NASA Astrophysics Data System (ADS)

Taghavi, M.; Cautenet, S.; Foret, G.

2004-06-01

During the ESCOMPTE precampaign (summer 2000, over Southern France), a 3-day period of intensive observation (IOP0), associated with ozone peaks, has been simulated. The comprehensive RAMS model, version 4.3, coupled on-line with a chemical module including 29 species, is used to follow the chemistry of the polluted zone. This efficient but time consuming method can be used because the code is installed on a parallel computer, the SGI 3800. Two runs are performed: run 1 with a single grid and run 2 with two nested grids. The simulated fields of ozone, carbon monoxide, nitrogen oxides and sulfur dioxide are compared with aircraft and surface station measurements. The 2-grid run looks substantially better than the run with one grid because the former takes the outer pollutants into account. This on-line method helps to satisfactorily retrieve the chemical species redistribution and to explain the impact of dynamics on this redistribution.

Magnetospheric convection and the high-latitude F2 ionosphere

NASA Technical Reports Server (NTRS)

Knudsen, W. C.

1974-01-01

Behavior of the polar ionospheric F layer as it is convected through the cleft, over the polar cap, and through the nightside F layer trough zone is investigated. Passage through the cleft adds approximately 200,000 ions per cu cm in the vicinity of the F2 peak and redistributes the ionization above approximately 400-km altitude to conform with an increased electron temperature. The redistribution of ionization above 400-km altitude forms the 'averaged' plasma ring seen at 1000-km altitude. The F layer is also raised by approximately 20 km in altitude by the convection electric field. The time required for passage across the polar cap (25 deg) is about the same as that required for the F layer peak concentration to decay by e. The F layer response to passage through the nightside soft electron precipitation zone should be similar to but less than its response to passage through the cleft.

Large scale mass redistribution and surface displacement from GRACE and SLR

NASA Astrophysics Data System (ADS)

Cheng, M.; Ries, J. C.; Tapley, B. D.

2012-12-01

Mass transport between the atmosphere, ocean and solid earth results in the temporal variations in the Earth gravity field and loading induced deformation of the Earth. Recent space-borne observations, such as GRACE mission, are providing extremely high precision temporal variations of gravity field. The results from 10-yr GRACE data has shown a significant annual variations of large scale vertical and horizontal displacements occurring over the Amazon, Himalayan region and South Asia, African, and Russian with a few mm amplitude. Improving understanding from monitoring and modeling of the large scale mass redistribution and the Earth's response are a critical for all studies in the geosciences, in particular for determination of Terrestrial Reference System (TRS), including geocenter motion. This paper will report results for the observed seasonal variations in the 3-dimentional surface displacements of SLR and GPS tracking stations and compare with the prediction from time series of GRACE monthly gravity solution.

Spacecraft Spin Rate Change due to Propellant Redistribution Between Tanks

NASA Astrophysics Data System (ADS)

Choi, Kyu Hong

1984-09-01

A bubble trapped in the liquid manifold of INTELSAT IV F-7 spacecraft caused a mass imbalance between the System 1 propellant tanks and a wobble half angle of 0.38 degree to 0.48 degree. A maneuver in May 14, 1980 passed the bubble through the axial jet and allowed propellant to redistribute. A 0.2 rpm change in spin rate was observed with an exponential decay time constant of 6 minutes. In this paper, moment of inertia, tank geometry and hydrodynamics models are derived to match the observed spin rate data. The values of the total mass of the propellant considered were 16, 19 and 20 Kgs with corresponding mass imbalances of 14.3, 15 and 15.1 Kgs, respectively. The result shows excellent agreement with observed spin rate data but it was necessary to assume a greater mass of hydrazine in the tanks than propellant accounting indicated.

COPYCAT; IBM OS system catalog utility routine. [IBM360,370; Assembly language

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

Engert, D.E.

COPYCAT is an OS utility program designed to produce an efficient system-wide catalog which may reside on many volumes. Substantial improvement in performance may also be obtained on a system with only a single catalog. First, catalog entries from many different catalogs may be redistributed to equalize the load on each catalog. Second, each individual catalog is restructured in a way designed to minimize the I/O time required for searching and updating. Redistribution and restructuring parameters are under user control. Model DSCB's for generation data groups and alias entries are also processed. Catalogs on all direct access devices, including datamore » cells, are supported. Backup copies may also be made.IBM360,370; Assembly language; OS/MVT, OS/MFT, OS/VS1 and OS/VS2 Release 1; A large region size is recommended since COPYCAT will use all of the core available to it for buffers..« less

Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation.

PubMed

Kim, Jongpal; Kim, Jihoon; Ko, Hyoungho

2015-12-31

To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG) readout chip is fabricated using a 0.13-μm complementary metal-oxide-semiconductor (CMOS) process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light interference, an alternating sampling and charge redistribution technique is also proposed. In the proposed technique, no additional power is consumed, and only three differential switches and one capacitor are required. The PPG readout channel consumes 26.4 μW and has an input referred current noise of 260 pArms.

Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation

PubMed Central

Kim, Jongpal; Kim, Jihoon; Ko, Hyoungho

2015-01-01

To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG) readout chip is fabricated using a 0.13-μm complementary metal–oxide–semiconductor (CMOS) process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light interference, an alternating sampling and charge redistribution technique is also proposed. In the proposed technique, no additional power is consumed, and only three differential switches and one capacitor are required. The PPG readout channel consumes 26.4 μW and has an input referred current noise of 260 pArms. PMID:26729122

The North-South Asymmetry of the Heliospheric Current Sheet: Results of an MHD Simulation

NASA Technical Reports Server (NTRS)

Usmanov, Arcadi V.; Goldstein, Melvyn L.

2013-01-01

A displacement of the heliospheric current sheet (HCS) south of the helioequator by approx.10deg was proposed by Simpson et al. (1996) as a possible explanation of the north-south asymmetry in the galactic cosmic rays observed by Ulysses during its first fast transit in 1994-1995. The idea was not supported by magnetic field measurements on Ulysses and, on this ground, was dismissed by Simpson et al. (1996). In addition, Erdos & Balogh (1998) argued that any north-south symmetry was unlikely as there should be flux balance between the magnetic sectors of opposite polarity. Nonetheless, many in the scientific community have accepted the original suggestion of Simpson et al. (1996) that a displacement of the HCS was responsible for the cosmic ray asymmetry. In this paper, using a magnetohydrodynamic model of the solar corona and solar wind that includes both dipole and quadrupole magnetic source terms, we show that a north-south asymmetry of the magnetic field on the Sun does not give rise to a displacement of the HCS. The lack of displacement of the HCS results from a latitudinal redistribution of magnetic flux near the Sun where the plasma beta much < 1. The latitudinal redistribution is a direct consequence of the magnetic field gradient between pole and equator. Near the Sun, the latitudinal gradient in magnetic field generates meridional flows directed equatorward that tend to relax the gradient in the magnetic field (to make it more latitude-independent) as heliocentric distance increases. If there is an asymmetry between north and south magnetic field strength then the meridional flows are also asymmetric (i.e., stronger in the hemisphere of stronger magnetic field). Because the magnetic fluxes (positive and negative) in the hemispheres must be equal, the redistribution shifts the HCS into balance by approx. 16 R(solar mass). At larger distances, where the magnetic field is relatively weak (beta much > 1), the HCS can be displaced if there is a difference in total pressure between the hemispheres.

Usefulness of automatic QT dispersion measurement for detecting exercise-induced myocardial ischemia.

PubMed

Takase, Bonpei; Masaki, Nobuyuki; Hattori, Hidemi; Ishihara, Masayuki; Kurita, Akira

2009-06-01

The electrocardiographic index of QT dispersion (QTd) is related to the occurrence of arrhythmia. In patients with suspected or known coronary artery disease, QTd may be affected by exercise. We investigated whether QTd that is automatically calculated by a newly developed computer system could be used as a marker of exercise-induced myocardial ischemia. The design of this study was prospective and observational. Eighty-three consecutive patients were enrolled in this study. Their QTd was measured at rest and after 3 min of exercise during exercise-stress Thallium-201 scintigraphy and compared with conventional ST-segment changes. The patients were classified into 4 groups (normal group, redistribution group, fixed defect group, redistribution with fixed defect group) based on the result of single photon emission computed tomography. As statistical analysis, one-way ANOVA with post-hoc Scheffe's method, receiver-operating characteristics (ROC) and multiple logistic regression analysis were performed. At rest, QTd was significantly greater (p<0.05) in the fixed defect group (52+/-21 ms) and the redistribution with fixed defect group (53+/-20 ms) than in the normal group (32+/-14 ms) and the redistribution group (31+/-16 ms). However, QTd tended to increase after exercise in the redistribution group, while QTd tended to decrease in the normal group, the fixed defect group, and the redistribution with fixed defect group (QTd after exercise, normal group, 28+/-17 ms, redistribution group, 35+/-19 ms, fixed defect group, 43+/-25 ms, redistribution with fixed defect group, 49+/-27 ms). Exercise significantly increased QTcd (RR interval-corrected QT dispersion) in the redistribution group. The best cut-off values of QTd and QTcd obtained from ROC curves for exercise-induced myocardial ischemia were 41.6 ms and 40.4 ms, respectively (Qtd--AUC 0.68, 95%CI 0.53- 0.83 and QTcd--AUC 0.67, 95%CI 0.55-0.80). Using these values as cut-off ones, QTd, QTcd, and conventional ST-segment change had comparable sensitivities and specificities for detecting exercise-induced myocardial ischemia (sensitivity - 60%, 58% and 49%, respectively;specificity - 78%, 80% and 83%, respectively). In addition, multiple logistic regression analysis showed that QTd (OR=2.01, 95%CI 1.15-4.10, p<0.05), QTcd (OR=2.12, 95% CI 1.02-4.30, p<0.05) and ST-segment change (OR=1.89, 95%CI 1.03-3.40, p<0.05), were the significantly associated with exercise-induced myocardial ischemia. QT dispersion and/or QTcd after exercise could be a useful marker for exercise-induced myocardial ischemia in routine clinical practice.

Constituent Redistribution in U-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

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

Galloway, Jack D.; Unal, Cetin; Matthews, Christopher

2016-09-30

Previous work done by Galloway, et. al. on EBR-II ternary (U-Pu-Zr) fuel constituent redistribution yielded accurate simulation data for the limited data sets of Zr redistribution. The data sets included EPMA scans of two different irradiated rods. First, T179, which was irradiated to 1.9 at% burnup, was analyzed. Second, DP16, which was irradiated to 11 at% burnup, was analyzed. One set of parameters that most accurately represented the zirconium profiles for both experiments was determined. Since the binary fuel (U-Zr) has previously been used as the driver fuel for sodium fast reactors (SFR) as well as being the likely drivermore » fuel if a new SFR is constructed, this same process has been initiated on the binary fuel form. From limited binary EPMA scans as well as other fuel characterization techniques, it has been observed that zirconium redistribution also occurs in the binary fuel, albeit at a reduced rate compared to observation in the ternary fuel, as noted by Kim et. al. While the rate of redistribution has been observed to be slower, numerous metallographs of U-Zr fuel show distinct zone formations.« less

Broad-Band Analysis of Polar Motion Excitations

NASA Astrophysics Data System (ADS)

Chen, J.

2016-12-01

Earth rotational changes, i.e. polar motion and length-of-day (LOD), are driven by two types of geophysical excitations: 1) mass redistribution within the Earth system, and 2) angular momentum exchange between the solid Earth (more precisely the crust) and other components of the Earth system. Accurate quantification of Earth rotational excitations has been difficult, due to the lack of global-scale observations of mass redistribution and angular momentum exchange. The over 14-years time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) have provided a unique means for quantifying Earth rotational excitations from mass redistribution in different components of the climate system. Comparisons between observed Earth rotational changes and geophysical excitations estimated from GRACE, satellite laser ranging (SLR) and climate models show that GRACE-derived excitations agree remarkably well with polar motion observations over a broad-band of frequencies. GRACE estimates also suggest that accelerated polar region ice melting in recent years and corresponding sea level rise have played an important role in driving long-term polar motion as well. With several estimates of polar motion excitations, it is possible to estimate broad-band noise variance and noise power spectra in each, given reasonable assumptions about noise independence. Results based on GRACE CSR RL05 solutions clearly outperform other estimates with the lowest noise levels over a broad band of frequencies.

The molecular mechanism of excitation in visual transduction and bacteriorhodopsin

PubMed Central

Lewis, Aaron

1978-01-01

An electronic theory of excitation is proposed and described in terms of a three-dimensional excited/ground-state energy surface which elucidates the photochemical and excited-state dynamics of rhodopsins. In this theory the primary action of light is to produce significant electron redistribution in the retinal, thereby generating new interactions that vibrationally excite and perturb the ground-state protein conformation. Thus, light energy causes charge redistribution in the retinal and induces transient charge-density assisted bond rearrangements (such as proton translocation) in the protein structure which is stabilized by subsequent retinal structural alteration. In this theory the isoprenoid chain of the retinal is considered a structurally pliable molecular entity that can generate charge redistributions and can be subsequently achieve intermediate conformations or various isomeric states to minimize the energy of the new protein structure generated by light. Thus, the 11-cis to all trans isomerization of the retinylidene chromophore is not considered a primary mechanism of excitation. An alternate biological role for this molecular process (which is eventually completed in all photoreceptors but not in bacterial rhodopsins) is to provide the irreversibility needed for effective quantum detection on the time scale of a neural response. Finally, it will be demonstrated that this mechanism, which readily accounts for the photophysical and photochemical data, can also be restated in terms of the Monod, Wyman, and Changeux terminology suggesting that aggregates of these pigments may function allosterically. PMID:273216

Organizations of food redistribution and rescue.

PubMed

Mousa, T Y; Freeland-Graves, J H

2017-11-01

Food insecurity affects 13.4% of the USA population, despite the fact that 30-40% of all food is deposited in a landfill. Food rescue nutrition is the process of redistribution of surplus food to the impoverished. The aim of this study is to document the extent of involvement of organizations in food rescue nutrition. In this cross-sectional study, a survey about organizations involved in food rescue nutrition was developed, validated, and then tested. Directors of 100 organizations involved in food rescue nutrition from eight Southwestern States in the USA participated in this research. These organizations provided an average of 2 million kg of food to more than 40,000 clients each month. Food assistance programs had an average of eight workers and 3081 volunteers. In addition to food, these organizations provided other services such as clothing, clinical, and childcare. The agencies encountered several challenges, including lack of resources that resulted in reducing food portions and turning away clients. The extent of involvement of community-based programs in food rescue nutrition was strong in eight Southwestern states in the USA. Organizations involved in food redistribution helped alleviate food insecurity in their clients. Sustainability of these charitable networks was dependent on availability of resources and sufficient volunteers. Health professionals should encourage these organizations by providing support through donations of time, money, and/or food. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Mechanism of action of anions on the electron transport chain in thylakoid membranes of higher plants.

PubMed

Singh-Rawal, Pooja; Zsiros, Ottó; Bharti, Sudhakar; Garab, Gyozo; Jajoo, Anjana

2011-04-01

With an aim to improve our understanding of the mechanisms behind specific anion effects in biological membranes, we have studied the effects of sodium salts of anions of varying valency in thylakoid membranes. Rates of electron transport of PS II and PS I, 77K fluorescence emission and excitation spectra, cyclic electron flow around PS I and circular dichroism (CD) spectra were measured in thylakoid membranes in order to elucidate a general mechanism of action of inorganic anions on photosynthetic electron transport chain. Re-distribution of absorbed excitation energy has been observed as a signature effect of inorganic anions. In the presence of anions, such as nitrite, sulphate and phosphate, distribution of absorbed excitation energy was found to be more in favor of Photosystem I (PS I). The amount of energy distributed towards PS I depended on the valency of the anion. In this paper, we propose for the first time that energy re-distribution and its valence dependence may not be the effect of anions per se. The entry of negative charge (anion) is accompanied by influx of positive charge (protons) to maintain a balance of charge across the thylakoid membranes. As reflected by the CD spectra, the observed energy re-distribution could be a result of structural rearrangements of the protein complexes of PS II caused by changes in the ionic environment of the thylakoid lumen.

Pressure ulcer incidence and progression in critically ill subjects: influence of low air loss mattress versus a powered air pressure redistribution mattress.

PubMed

Black, Joyce; Berke, Christine; Urzendowski, Gail

2012-01-01

The primary objective of this study was to compare facility-acquired pressure ulcer incidence and progression of pressure ulcers present on admission in critically ill patients, using 2 different support surfaces. We completed a comparison cohort study in a surgical intensive care unit (ICU). The study setting was a 12-bed cardiovascular ICU in a university-based hospital in the Midwestern United States. The sample comprised 52 critically ill patients; 31 were placed on low air loss weight-based pressure redistribution-microclimate management system beds and 21 were placed on integrated powered air pressure redistribution beds. Prior to the start of the study, 5 low airloss beds were placed in open rooms in the cardiovascular surgical ICU. Inclusion criteria were anticipated ICU stay of 3 days, and patients did not receive a speciality bed for pulmonary or wound issues. Initial assessment of the patients included risk assessment and prior events that would increase risk for pressure ulcer development such as extended time in operating room, along with skin assessment for existing pressure ulcers. Subjects in both groups had ongoing skin assessment every 3 to 4 days and a subjective evaluation of heel elevation and turning or repositioning by the researcher. Data were collected until the subjects were dismissed from the ICU. Patients admitted to the unit were assigned to open rooms following the usual protocols. The mean length of stay was 7.0 days, with an 8.1-day length of stay for subjects on "low air loss with microclimate management" beds (LAL-MCM) and 6.6 days on the integrated power pressure air redistribution (IP-AR) beds (P = NS). The incidence of pressure ulcers on the buttocks, sacrum, or coccyx was 0% (0/31) on the low air loss bed and 18% (4/21) on the IP-AR bed (P = .046). Five subjects had 6 pressure ulcers on admission. Two pressure ulcers on 2 patients worsened on the integrated power air redistribution beds, which required specialty bed rental costing the facility $4116. No subjects on the low air loss beds experienced worsening of existing pressure ulcer. One patient with a deep tissue injury present on admission improved on the LAL-MCM bed. The IP-AR beds were approximately 7 years old, and the LAL-MCM beds were new. Critically ill subjects placed on low air loss beds with microclimate management in surgical ICUs had a lower pressure ulcer incidence than those placed on integrated powered air pressure redistribution beds. The clinical performance of the IP-AR surfaces may have been influenced by their age.

Carbon recovery rates following different wildfire risk mitigation treatments

Treesearch

M. Hurteau; M. North

2010-01-01

Sequestered forest carbon can provide a climate change mitigation benefit, but in dry temperate forests, wildfire poses a reversal risk to carbon offset projects. Reducing wildfire risk requires a reduction in and redistribution of carbon stocks, the benefit of which is only realized when wildfire occurs. To estimate the time needed to recover carbon removed and...

76 FR 40967 - Options Price Reporting Authority; Notice of Filing and Immediate Effectiveness of Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-12

... Exchange Act of 1934 (``Act'') \\1\\ and Rule 608 thereunder,\\2\\ notice is hereby given that on June 24, 2011... Internet Access to Real- Time OPRA Data.'' The definitions of the terms ``Hosted Solution'' and ``Client... circumstances in which an OPRA Vendor may pay OPRA's ``Internet Service Only'' Redistribution Fee ($650/month...

The International Service for the Geoid and its products

NASA Astrophysics Data System (ADS)

Reguzzoni, Mirko; Sona, Giovanna; Barzaghi, Riccardo; Sansò, Fernando; Albertella, Alberta; Carrion, Daniela; Iapige De Gaetani, Carlo; Rossi, Lorenzo

2017-04-01

The International Service for the Geoid (ISG) was established in 1992 and it is currently an official service of the International Association of Geodesy (IAG). Its activities are coordinated by the International Gravity Field Service (IGFS) and they are also related to those of the IAG Commission 2 on Gravity Field. ISG is hosted by Politecnico di Milano in Italy. The main task of ISG is to collect, analyze and redistribute local, regional and even continental geoid models, which are therefore the main products of the service. In this work the geoid repository is described, specifying the information provided for the models, the unified ASCII format used for their storing and the possible policy rules for their redistribution. Moreover, the current state-of-art of the repository is presented, in particular analyzing the geographical distribution of the available models and their years of computation. Note that not only the latest released geoid models are collected in the ISG repository, but also less recent ones, with the aim of keeping memory of the progress done in this research field during the years. Software for estimating and handling geoid models is provided too. Apart from distributing geoid models and software, the service has also educational and research purposes. From this perspective, additional products are the international schools on geoid computation that have been organized by ISG since 1994, basically every 2-3 years. A historical overview of the schools, with emphasis on the school program and its evolution in time, is here presented. As for the research activities, apart from participating to international projects and working groups, the main ISG product was the publication of the IGeS Bulletin in the past and the Newton's Bulletin nowadays, in cooperation with the International Gravimetric Bureau (BGI). The Newton's Bulletin has a technical and applied nature and it has been recently selected by the geodetic community for publications on the assessment of EGM2008 and GOCE global gravity models. Finally a short presentation of the service website as the main platform for the product distribution and advertising is here provided.

A density distribution algorithm for bone incorporating local orthotropy, modal analysis and theories of cellular solids.

PubMed

Impelluso, Thomas J

2003-06-01

An algorithm for bone remodeling is presented which allows for both a redistribution of density and a continuous change of principal material directions for the orthotropic material properties of bone. It employs a modal analysis to add density for growth and a local effective strain based analysis to redistribute density. General re-distribution functions are presented. The model utilizes theories of cellular solids to relate density and strength. The code predicts the same general density distributions and local orthotropy as observed in reality.

The ‘neutron deficit’ in the JET tokamak

NASA Astrophysics Data System (ADS)

Weisen, H.; Kim, Hyun-Tae; Strachan, J.; Scott, S.; Baranov, Y.; Buchanan, J.; Fitzgerald, M.; Keeling, D.; King, D. B.; Giacomelli, L.; Koskela, T.; Weisen, M. J.; Giroud, C.; Maslov, M.; Core, W. G.; Zastrow, K.-D.; Syme, D. B.; Popovichev, S.; Conroy, S.; Lengar, I.; Snoj, L.; Batistoni, P.; Santala, M.; Contributors, JET

2017-07-01

The measured D-D neutron rate of neutral beam heated JET baseline and hybrid H-modes in deuterium is found to be between approximately 50% and 100% of the neutron rate expected from the TRANSP code, depending on the plasma parameters. A number of candidate explanations for the shortfall, such as fuel dilution, errors in beam penetration and effectively available beam power have been excluded. As the neutron rate in JET is dominated by beam-plasma interactions, the ‘neutron deficit’ may be caused by a yet unidentified form of fast particle redistribution. Modelling, which assumes fast particle transport to be responsible for the deficit, indicates that such redistribution would have to happen at time scales faster than both the slowing down time and the energy confinement time. Sawteeth and edge localised modes are found to make no significant contribution to the deficit. There is also no obvious correlation with magnetohydrodynamic activity measured using magnetic probes at the tokamak vessel walls. Modelling of fast particle orbits in the 3D fields of neoclassical tearing modes shows that realistically sized islands can only contribute a few percent to the deficit. In view of these results it appears unlikely that the neutron deficit results from a single physical process in the plasma.

Redistribution of Military Forces in Asia-Pacific Region

DTIC Science & Technology

2008-03-15

country. Influential New York Times columnist , William Safire recently called for the military forces withdrawal “because the US does not want to...Tripwire: Korea and US Foreign Policy in a Changed World, Cato Institute columnist Doug Bando points out that it is time to recognize that South...Disarming North Korea’s Nukes: Prospects for the 6-PartyTalks,” Global Beat Syndicate , 1 March 2004; 1-4; available from http://www.bu.edu/globalbeat

Injectable barriers for waste isolation

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

Persoff, P.; Finsterle, S.; Moridis, G.J.

In this paper the authors report laboratory work and numerical simulation done in support of development and demonstration of injectable barriers formed from either of two fluids: colloidal silica or polysiloxane. Two principal problems addressed here are control of gel time and control of plume emplacement in the vadose zone. Gel time must be controlled so that the viscosity of the barrier fluid remains low long enough to inject the barrier, but increases soon enough to gel the barrier in place. During injection, the viscosity must be low enough to avoid high injection pressures which could uplift or fracture themore » formation. To test the grout gel time in the soil, the injection pressure was monitored as grouts were injected into sandpacks. When grout is injected into the vadose zone, it slumps under the influence of gravity, and redistributes due to capillary forces as it gels. The authors have developed a new module for the reservoir simulator TOUGH2 to model grout injection into the vadose zone, taking into account the increase of liquid viscosity as a function of gel concentration and time. They have also developed a model to calculate soil properties after complete solidification of the grout. The numerical model has been used to design and analyze laboratory experiments and field pilot tests. The authors present the results of computer simulations of grout injection, redistribution, and solidification.« less

Some characteristics of intense geomagnetic storms and their energy budget

NASA Astrophysics Data System (ADS)

Vichare, Geeta; Alex, S.; Lakhina, G. S.

2005-03-01

The present study analyses nine intense geomagnetic storms (∣Dst∣ > 175 nT) with the aid of ACE satellite measurements and ground magnetic field values at Alibag Magnetic Observatory. The study confirms the crucial role of southward IMF in triggering the storm main phase as well as controlling the magnitude of the storm. The main phase interval shows clear dependence on the duration of southward IMF. An attempt is made to identify the multipeak signature in the ring current energy injection rate during main phase of the storm. In order to quantify the energy budget of magnetic storms, the present paper computes the solar wind energies, magnetospheric coupling energies, auroral and Joule heating energies, and the ring current energies for each storm under examination. Computation of the solar wind- magnetosphere coupling function considers the variation of the size of the magnetosphere by using the measured solar wind ram pressure. During the main phase of the storm, the solar wind kinetic energy ranges from 9 × 1017 to 72 × 1017 J with an average of 30 × 1017 J; the total energy dissipated in the auroral ionosphere varies between 2 × 1015 and 9 × 1015 J, whereas ring current energies range from 8 × 1015 to 19 × 1015 J. For the total storm period, about 3.5% of total solar wind kinetic energy is available for the redistribution in the magnetosphere, and around 20% of this goes into the inner magnetosphere and in the auroral ionosphere of both the hemispheres. It is found that during main phase of the storm, almost 5% of the total solar wind kinetic energy is available for the redistribution in the magnetosphere, whereas during the recovery phase the percentage becomes 2.3%.

Magnetic nano-oscillator driven by pure spin current.

PubMed

Demidov, Vladislav E; Urazhdin, Sergei; Ulrichs, Henning; Tiberkevich, Vasyl; Slavin, Andrei; Baither, Dietmar; Schmitz, Guido; Demokritov, Sergej O

2012-12-01

With the advent of pure-spin-current sources, spin-based electronic (spintronic) devices no longer require electrical charge transfer, opening new possibilities for both conducting and insulating spintronic systems. Pure spin currents have been used to suppress noise caused by thermal fluctuations in magnetic nanodevices, amplify propagating magnetization waves, and to reduce the dynamic damping in magnetic films. However, generation of coherent auto-oscillations by pure spin currents has not been achieved so far. Here we demonstrate the generation of single-mode coherent auto-oscillations in a device that combines local injection of a pure spin current with enhanced spin-wave radiation losses. Counterintuitively, radiation losses enable excitation of auto-oscillation, suppressing the nonlinear processes that prevent auto-oscillation by redistributing the energy between different modes. Our devices exhibit auto-oscillations at moderate current densities, at a microwave frequency tunable over a wide range. These findings suggest a new route for the implementation of nanoscale microwave sources for next-generation integrated electronics.

Be2D: A model to understand the distribution of meteoric 10Be in soilscapes

NASA Astrophysics Data System (ADS)

Campforts, Benjamin; Vanacker, Veerle; Vanderborght, Jan; Govers, Gerard

2016-04-01

Cosmogenic nuclides have revolutionised our understanding of earth surface process rates. They have become one of the standard tools to quantify soil production by weathering, soil redistribution and erosion. Especially Beryllium-10 has gained much attention due to its long half-live and propensity to be relatively conservative in the landscape. The latter makes 10Be an excellent tool to assess denudation rates over the last 1000 to 100 × 103 years, bridging the anthropogenic and geological time scale. Nevertheless, the mobility of meteoric 10Be in soil systems makes translation of meteoric 10Be inventories into erosion and deposition rates difficult. Here we present a coupled soil hillslope model, Be2D, that is applied to synthetic and real topography to address the following three research questions. (i) What is the influence of vertical meteoric Be10 mobility, caused by chemical mobility, clay translocation and bioturbation, on its lateral redistribution over the soilscape, (ii) How does vertical mobility influence erosion rates and soil residence times inferred from meteoric 10Be inventories and (iii) To what extent can a tracer with a half-life of 1.36 Myr be used to distinguish between natural and human-disturbed soil redistribution rates? The model architecture of Be2D is designed to answer these research questions. Be2D is a dynamic model including physical processes such as soil formation, physical weathering, clay migration, bioturbation, creep, overland flow and tillage erosion. Pathways of meteoric 10Be mobility are simulated using a two step approach which is updated each timestep. First, advective and diffusive mobility of meteoric 10Be is simulated within the soil profile and second, lateral redistribution because of lateral soil fluxes is calculated. The performance and functionality of the model is demonstrated through a number of synthetic and real model runs using existing datasets of meteoric 10Be from case-studies in southeastern US. Brute force optimisation allows reliably parameter constraining, resulting in a good agreement between simulated and observed meteoric 10Be concentrations and inventories. Our simulations suggest that meteoric 10Be can be used as a tracer to unravel human impact on soil fluxes when soils have a high affinity to sorb meteoric 10Be.

76 FR 56482 - Sunshine Act Meeting of the Operations & Regulations Committee of the LSC Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-13

... and Congress statutory changes concerning replacement of decennial census poverty data in the... poverty data, phasing in the first redistribution over two years, and redistributing funds triennially...

Residential relocation and regional redistribution of the elderly in the USA and Germany.

PubMed

Serow, W J; Friedrich, K; Haas, W H

1996-01-01

"This paper reviews some of the principal differences and similarities in the migration and spatial redistribution behavior of the older populations of the USA and of Germany.... The paper is divided into three distinct parts. The paper first reviews actual and prospective redistribution of the older population, with regard to interregional shifts of population as well as to changes in concentration along an urban-rural continuum. Following these macroscopic elements, the paper then moves to a presentation of the results of two ex post facto surveys (one taken in the USA and the other in Germany) of recent older movers in order to compare the motivations expressed for the move and the present degree of satisfaction with it. The concluding section considers the implications of redistribution at both geographic levels and of mover satisfaction in light of political developments as they are presently unfolding in Europe." excerpt

Novel Regulation of Aquaporins during Osmotic Stress1

PubMed Central

Vera-Estrella, Rosario; Barkla, Bronwyn J.; Bohnert, Hans J.; Pantoja, Omar

2004-01-01

Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions. PMID:15299122

Redistributing wealth to families: the advantages of the MYRIADE model.

PubMed

Legendre, François; Lorgnet, Jean-Paul; Thibault, Florence

2005-10-01

This study aims to shed light on the main characteristics of the French system for redistributing wealth to families through tax revenues and social transfers. For the purposes of this exercise, the authors used the MYRIADE microsimulation model, which covers most of the redistribution system, though it is limited to monetary flows such as family benefits, housing allowances, minimum social welfare payments, income tax, and tax on furnished accommodation. The authors used a particular methodology to highlight the way this redistribution works; rather than calculate the difference between each family's disposable income and their gross primary income, they opted to isolate the variation in disposable income that could be attributed to the youngest member of each family where there is at least one child under the age of 25. The average increase in disposable income that this child contributes to his or her family amounts to in200 per month.

Novel regulation of aquaporins during osmotic stress.

PubMed

Vera-Estrella, Rosario; Barkla, Bronwyn J; Bohnert, Hans J; Pantoja, Omar

2004-08-01

Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions.

Medicare financing and redistribution in british columbia, 1992 and 2002.

PubMed

McGrail, Kimberlyn

2007-05-01

Equity in healthcare in British Columbia is defined as the provision of services based on need rather than ability to pay and a separation of contributions to financing from the use of services. Physician and hospital services in Canada are financed mainly through general tax revenues, and there is a perception that this financing is progressive. This paper uses Gini coefficients, concentration indexes and Kakwani indexes of progressivity to assess the progressivity of medicare financing in British Columbia in 1992 and 2002. It also measures the overall redistributive effect of medicare services, considering both contributions to financing and use of hospital and physician services. The conclusion is that medicare does redistribute across income groups, but this redistribution is the result solely of the positive correlation between health status and income; financing is nearly proportionate across income groups, but use is higher among lower-income groups. Informed public debate requires a better understanding of these concepts of equity.

Importance of Cross-redistribution in Scattering Polarization of Spectral Lines: The Cases of {sup 3}P−{sup 3}S Triplets of Mg i and Ca i

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

Sampoorna, M.; Nagendra, K. N., E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in

Scattering on a multi-level atomic system has dominant contributions from resonance and Raman scattering. While initial and final levels are the same for resonance scattering, they are different for Raman scattering. The frequency redistribution for resonance scattering is described by the usual partial frequency redistribution functions of Hummer, while that for Raman scattering is described by cross-redistribution (XRD) function. In the present paper, we investigate the importance of XRD on linear polarization profiles of {sup 3}P−{sup 3}S triplets of Mg i and Ca i formed in an isothermal one-dimensional atmosphere. We show that XRD produces significant effects on the linearmore » polarization profiles when the wavelength separations between the line components of the multiplet are small, like in the cases of Mg i b and Ca i triplets.« less

Exposure to inequality affects support for redistribution

PubMed Central

Sands, Melissa L.

2017-01-01

The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals’ support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a “millionaire’s tax.” Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals’ willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject. PMID:28069960

Pressure-strain energy redistribution in compressible turbulence: return-to-isotropy versus kinetic-potential energy equipartition

NASA Astrophysics Data System (ADS)

Lee, Kurnchul; Venugopal, Vishnu; Girimaji, Sharath S.

2016-08-01

Return-to-isotropy and kinetic-potential energy equipartition are two fundamental pressure-moderated energy redistributive processes in anisotropic compressible turbulence. Pressure-strain correlation tensor redistributes energy among various Reynolds stress components and pressure-dilatation is responsible for energy reallocation between dilatational kinetic and potential energies. The competition and interplay between these pressure-based processes are investigated in this study. Direct numerical simulations (DNS) of low turbulent Mach number dilatational turbulence are performed employing the hybrid thermal Lattice Boltzman method (HTLBM). It is found that a tendency towards equipartition precedes proclivity for isotropization. An evolution towards equipartition has a collateral but critical effect on return-to-isotropy. The preferential transfer of energy from strong (rather than weak) Reynolds stress components to potential energy accelerates the isotropization of dilatational fluctuations. Understanding of these pressure-based redistributive processes is critical for developing insight into the character of compressible turbulence.

The Southwest Pacific Ocean circulation and climate experiment (SPICE)

NASA Astrophysics Data System (ADS)

Ganachaud, A.; Cravatte, S.; Melet, A.; Schiller, A.; Holbrook, N. J.; Sloyan, B. M.; Widlansky, M. J.; Bowen, M.; Verron, J.; Wiles, P.; Ridgway, K.; Sutton, P.; Sprintall, J.; Steinberg, C.; Brassington, G.; Cai, W.; Davis, R.; Gasparin, F.; Gourdeau, L.; Hasegawa, T.; Kessler, W.; Maes, C.; Takahashi, K.; Richards, K. J.; Send, U.

2014-11-01

The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE) is an international research program under the auspices of CLIVAR. The key objectives are to understand the Southwest Pacific Ocean circulation and the South Pacific Convergence Zone (SPCZ) dynamics, as well as their influence on regional and basin-scale climate patterns. South Pacific thermocline waters are transported in the westward flowing South Equatorial Current (SEC) toward Australia and Papua-New Guinea. On its way, the SEC encounters the numerous islands and straits of the Southwest Pacific and forms boundary currents and jets that eventually redistribute water to the equator and high latitudes. The transit in the Coral, Solomon, and Tasman Seas is of great importance to the climate system because changes in either the temperature or the amount of water arriving at the equator have the capability to modulate the El Niño-Southern Oscillation, while the southward transports influence the climate and biodiversity in the Tasman Sea. After 7 years of substantial in situ oceanic observational and modeling efforts, our understanding of the region has much improved. We have a refined description of the SPCZ behavior, boundary currents, pathways, and water mass transformation, including the previously undocumented Solomon Sea. The transports are large and vary substantially in a counter-intuitive way, with asymmetries and gating effects that depend on time scales. This paper provides a review of recent advancements and discusses our current knowledge gaps and important emerging research directions.

Optimization of return electrodes in neurostimulating arrays

NASA Astrophysics Data System (ADS)

Flores, Thomas; Goetz, Georges; Lei, Xin; Palanker, Daniel

2016-06-01

Objective. High resolution visual prostheses require dense stimulating arrays with localized inputs of individual electrodes. We study the electric field produced by multielectrode arrays in electrolyte to determine an optimal configuration of return electrodes and activation sequence. Approach. To determine the boundary conditions for computation of the electric field in electrolyte, we assessed current dynamics using an equivalent circuit of a multielectrode array with interleaved return electrodes. The electric field modeled with two different boundary conditions derived from the equivalent circuit was then compared to measurements of electric potential in electrolyte. To assess the effect of return electrode configuration on retinal stimulation, we transformed the computed electric fields into retinal response using a model of neural network-mediated stimulation. Main results. Electric currents at the capacitive electrode-electrolyte interface redistribute over time, so that boundary conditions transition from equipotential surfaces at the beginning of the pulse to uniform current density in steady state. Experimental measurements confirmed that, in steady state, the boundary condition corresponds to a uniform current density on electrode surfaces. Arrays with local return electrodes exhibit improved field confinement and can elicit stronger network-mediated retinal response compared to those with a common remote return. Connecting local return electrodes enhances the field penetration depth and allows reducing the return electrode area. Sequential activation of the pixels in large monopolar arrays reduces electrical cross-talk and improves the contrast in pattern stimulation. Significance. Accurate modeling of multielectrode arrays helps optimize the electrode configuration to maximize the spatial resolution, contrast and dynamic range of retinal prostheses.

The impact of soil redistribution on SOC pools in a Mediterranean agroforestry catchment

NASA Astrophysics Data System (ADS)

Quijano, Laura; Gaspar, Leticia; Lizaga, Iván; Navas, Ana

2017-04-01

Soil redistribution processes play an important role influencing the spatial distribution patterns of soil and associated soil organic carbon (SOC) at landscape scale. Information on drivers of SOC dynamics is key for evaluating both soil degradation and SOC stability that can affect soil quality and sustainability. 137Cs measurements provide a very effective tool to infer spatial patterns of soil redistribution and quantify soil redistribution rates in different landscapes, but to date these data are scarce in mountain Mediterranean agroecosystems. We evaluate the effect of soil redistribution on SOC and SOC pools in relation to land use in a Mediterranean mountain catchment (246 ha). To this purpose, two hundred and four soil bulk cores were collected on a 100 m grid in the Estaña lakes catchment located in the central sector of the Spanish Pyrenees (31T 4656250N 295152E). The study area is an agroforestry and endorheic catchment characterized by the presence of evaporite dissolution induced dolines, some of which host permanent lakes. The selected landscape is representative of rainfed areas of Mediterranean continental climate with erodible lithology and shallow soils, and characterized by an intense anthropogenic activity through cultivation and water management. The cultivated and uncultivated areas are heterogeneously distributed. SOC and SOC pools (the active and decomposable fraction, ACF and the stable carbon fraction SCF) were measured by the dry combustion method and soil redistribution rates were derived from 137Cs measurements. The results showed that erosion predominated in the catchment, most of soil samples were identified as eroded sites (n=114) with an average erosion rate of 26.9±51.4 Mg ha-1 y-1 whereas the mean deposition rate was 13.0±24.2 Mg ha-1 y-1. In cultivated soils (n=54) the average of soil erosion rate was significantly higher (78.5±74.4 Mg ha-1 y-1) than in uncultivated soils (6.8±10.4 Mg ha-1 y-1). Similarly, the mean of soil deposition rate in cultivated soils (n=22) was significantly higher (42.6±35.1 Mg ha-1 y-1) than in uncultivated soils (3.4±3.2 Mg ha-1 y-1). The mean SOC content for all soil samples was 2.5±2.0%. In uncultivated soils, significantly higher (P<0.01) amounts of SOC (3.0±2.6%), ACF (2.1±0.7%) and SCF (0.9±0.4%) were found compared to cultivated soils where the means were 1.1±0.7%, 0.7±0.5% and 0.4±0.3%, respectively. Significant (P<0.05) correlations between SOC, SOC pools and soil redistribution rates indicate that the distribution of SOC pools were significantly affected by soil redistribution in the study area. SOC and SOC pools were significantly higher at depositional (n=90, 2.8±1.8%) than at eroded sampling points (2.2±2.1%). ACF shows greater differences at eroding sites and at depositional sites than SCF reflecting that ACF is more sensitive to soil redistribution processes. Our findings emphasize the role of soil redistribution and land use in influencing the dynamics of SOC, information that can be also relevant in soil management. Improving the knowledge on the relationships between land use, soil redistribution processes and SOC fractions is of interest, especially in these Mediterranean rapidly changing landscapes.

Mechanisms underlying the redistribution of particles among the lung's alveolar macrophages during alveolar phase clearance

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

Lehnert, B.E.; Oritz, J.B.; Steinkamp, J.A.

1991-01-01

In order to obtain information about the particle redistribution phenomenon following the deposition of inhaled particles, as well as to obtain information about some of the mechanisms that may be operable in the redistribution of particles, lavaged lung free cell analyses and transmission electron microscopic (TEM) analyses of lung tissue and were performed using lungs from rats after they were subchronically exposed to aerosolized dioxide (TiO{sub 2}). TEM analyses indicated that the in situ autolysis of particle-containing Alveolar Macropages (AM) is one important mechanism involved in the redistribution of particles. Evidence was also obtained that indicated that the engulfment ofmore » one particle-containing phagocyte by another phagocyte also occurs. Another prominent mechanism of the particle redistribution phenomenon may be the in situ proliferation of particle-laden AM. We used the macrophage cell line J774A.1 as a surrogate for AM to investigate how different particulate loads in macrophages may affect their abilities to proliferate. These in vitro investigations indicated that the normal rate of proliferation of macrophages is essentially unaffected by the containment of relatively high particulate burdens. Overall, the results of our investigations suggest that in situ autolysis of particle-containing AM and the rephagocytosis of freed particles by other phagocytes, the phagocytosis of effete and disintegrating particle-containing phagocytes by other AM, and the in situ division of particle-containing AM are likely mechanisms that underlie the post-depositional redistribution of particles among the lung's AM during alveolar phase clearance. 19 refs., 8 figs., 2 tabs.« less

Competition for light and water in a coupled soil-plant system

DOE PAGES

Manoli, Gabriele; Huang, Cheng -Wei; Bonetti, Sara; ...

2017-08-14

Here, it is generally accepted that resource availability shapes the structure and function of many ecosystems. Within the soil-plant-atmosphere (SPA) system, resource availability fluctuates in space and time whereas access to resources by individuals is further impacted by plant-to-plant competition. Likewise, transport and transformation of resources within an individual plant is governed by numerous interacting biotic and abiotic processes. The work here explores the co-limitations on water losses and carbon uptake within the SPA arising from fluctuating resource availability and competition. In particular, the goal is to unfold the interplay between plant access and competition for water and light, asmore » well as the impact of transport/redistribution processes on leaf-level carbon assimilation and water fluxes within forest stands. A framework is proposed that couples a three-dimensional representation of soil-root exchanges with a one-dimensional description of stem water flow and storage, canopy photosynthesis, and transpiration. The model links soil moisture redistribution, root water uptake, xylem water flow and storage, leaf potential and stomatal conductance as driven by supply and demand for water and carbon. The model is then used to investigate plant drought resilience of overstory-understory trees simultaneously competing for water and light. Simulation results reveal that understory-overstory interactions increase ecosystem resilience to drought (i.e. stand-level carbon assimilation rates and water fluxes can be sustained at lower root-zone soil water potentials). This resilience enhancement originates from reduced transpiration (due to shading) and hydraulic redistribution in soil supporting photosynthesis over prolonged periods of drought. In particular, the presence of different rooting systems generates localized hydraulic redistribution fluxes that sustain understory transpiration through overstory-understory interactions. Such complex SPA dynamics cannot be properly summarized by equivalent ecosystem-scale Resistor-Capacitor (RC) rep- resentation. However our results show that, with proper averaging across water flow paths, RC models can provide reasonable estimates of stand-level water and carbon fluxes during inter-storm periods.« less

Carbon redistribution during interrill erosion in subtropical forests: Effects of leaf litter diversity and soil fauna

NASA Astrophysics Data System (ADS)

Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

2016-04-01

Soil erosion is crucial for degradation of carbon (C) from their pools in the soil. If C of the eroded sediment and runoff are not only related to soil pools but also resulting additively from decomposition of litter cover, the system gets more complex. The role of these amounts for C cycling in a forest environment is not yet known properly and thus, the aim of this study was to investigate the role of leaf litter diversity, litter cover and soil fauna on C redistribution during interrill erosion. We established 96 runoff plots that were deployed with seven domestic leaf litter species resulting in none species (bare ground), 1-species, 2-species and 4-species mixtures. Every second runoff plot was equipped with a fauna extinction feature to investigate the role of soil meso- and macrofauna. Erosion processes were initiated using a rainfall simulator at two time steps (summer 2012 and autumn 2012) to investigate the role of leaf litter decomposition on C redistribution. C fluxes during 20 min rainfall simulation were 99.13 ± 94.98 g/m². C fluxes and C contents both were affected by soil fauna. C fluxes were higher with presence of soil fauna due to loosening and slackening of the soil surface rather than due to faster decomposition of leaves. In contrast, C contents were higher in the absence of soil fauna possibly resulting from a missing dilution effect in the top soil layer. Leaf litter diversity did not affect C fluxes, but indirectly affected C contents as it increased the soil fauna effect with higher leaf litter diversity due to superior food supply. Initial C contents in the soil mainly determined those of the eroded sediment. For future research, it will be essential to introduce a long-term decomposition experiment to get further insights into the processes of C redistribution.

Competition for light and water in a coupled soil-plant system

NASA Astrophysics Data System (ADS)

Manoli, Gabriele; Huang, Cheng-Wei; Bonetti, Sara; Domec, Jean-Christophe; Marani, Marco; Katul, Gabriel

2017-10-01

It is generally accepted that resource availability shapes the structure and function of many ecosystems. Within the soil-plant-atmosphere (SPA) system, resource availability fluctuates in space and time whereas access to resources by individuals is further impacted by plant-to-plant competition. Likewise, transport and transformation of resources within an individual plant is governed by numerous interacting biotic and abiotic processes. The work here explores the co-limitations on water losses and carbon uptake within the SPA arising from fluctuating resource availability and competition. In particular, the goal is to unfold the interplay between plant access and competition for water and light, as well as the impact of transport/redistribution processes on leaf-level carbon assimilation and water fluxes within forest stands. A framework is proposed that couples a three-dimensional representation of soil-root exchanges with a one-dimensional description of stem water flow and storage, canopy photosynthesis, and transpiration. The model links soil moisture redistribution, root water uptake, xylem water flow and storage, leaf potential and stomatal conductance as driven by supply and demand for water and carbon. The model is then used to investigate plant drought resilience of overstory-understory trees simultaneously competing for water and light. Simulation results reveal that understory-overstory interactions increase ecosystem resilience to drought (i.e. stand-level carbon assimilation rates and water fluxes can be sustained at lower root-zone soil water potentials). This resilience enhancement originates from reduced transpiration (due to shading) and hydraulic redistribution in soil supporting photosynthesis over prolonged periods of drought. In particular, the presence of different rooting systems generates localized hydraulic redistribution fluxes that sustain understory transpiration through overstory-understory interactions. Such complex SPA dynamics cannot be properly summarized by equivalent ecosystem-scale Resistor-Capacitor (RC) representation. However our results show that, with proper averaging across water flow paths, RC models can provide reasonable estimates of stand-level water and carbon fluxes during inter-storm periods.

Regulation of angiotensin II-induced neuromodulation by MARCKS in brain neurons.

PubMed

Lu, D; Yang, H; Lenox, R H; Raizada, M K

1998-07-13

Angiotensin II (Ang II) exerts chronic stimulatory actions on tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), and the norepinephrine transporter (NET), in part, by influencing the transcription of their genes. These neuromodulatory actions of Ang II involve Ras-Raf-MAP kinase signal transduction pathways (Lu, D., H. Yang, and M.K. Raizada. 1997. J. Cell Biol. 135:1609-1617). In this study, we present evidence to demonstrate participation of another signaling pathway in these neuronal actions of Ang II. It involves activation of protein kinase C (PKC)beta subtype and phosphorylation and redistribution of myristoylated alanine-rich C kinase substrate (MARCKS) in neurites. Ang II caused a dramatic redistribution of MARCKS from neuronal varicosities to neurites. This was accompanied by a time-dependent stimulation of its phosphorylation, that was mediated by the angiotensin type 1 receptor subtype (AT1). Incubation of neurons with PKCbeta subtype specific antisense oligonucleotide (AON) significantly attenuated both redistribution and phosphorylation of MARCKS. Furthermore, depletion of MARCKS by MARCKS-AON treatment of neurons resulted in a significant decrease in Ang II-stimulated accumulation of TH and DbetaH immunoreactivities and [3H]NE uptake activity in synaptosomes. In contrast, mRNA levels of TH, DbetaH, and NET were not influenced by MARKS-AON treatment. MARCKS pep148-165, which contains PKC phosphorylation sites, inhibited Ang II stimulation of MARCKS phosphorylation and reduced the amount of TH, DbetaH, and [3H]NE uptake in neuronal synaptosomes. These observations demonstrate that phosphorylation of MARCKS by PKCbeta and its redistribution from varicosities to neurites is important in Ang II-induced synaptic accumulation of TH, DbetaH, and NE. They suggest that a coordinated stimulation of transcription of TH, DbetaH, and NET, mediated by Ras-Raf-MAP kinase followed by their transport mediated by PKCbeta-MARCKS pathway are key in persistent stimulation of Ang II's neuromodulatory actions.

Competition for light and water in a coupled soil-plant system

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

Manoli, Gabriele; Huang, Cheng -Wei; Bonetti, Sara

Here, it is generally accepted that resource availability shapes the structure and function of many ecosystems. Within the soil-plant-atmosphere (SPA) system, resource availability fluctuates in space and time whereas access to resources by individuals is further impacted by plant-to-plant competition. Likewise, transport and transformation of resources within an individual plant is governed by numerous interacting biotic and abiotic processes. The work here explores the co-limitations on water losses and carbon uptake within the SPA arising from fluctuating resource availability and competition. In particular, the goal is to unfold the interplay between plant access and competition for water and light, asmore » well as the impact of transport/redistribution processes on leaf-level carbon assimilation and water fluxes within forest stands. A framework is proposed that couples a three-dimensional representation of soil-root exchanges with a one-dimensional description of stem water flow and storage, canopy photosynthesis, and transpiration. The model links soil moisture redistribution, root water uptake, xylem water flow and storage, leaf potential and stomatal conductance as driven by supply and demand for water and carbon. The model is then used to investigate plant drought resilience of overstory-understory trees simultaneously competing for water and light. Simulation results reveal that understory-overstory interactions increase ecosystem resilience to drought (i.e. stand-level carbon assimilation rates and water fluxes can be sustained at lower root-zone soil water potentials). This resilience enhancement originates from reduced transpiration (due to shading) and hydraulic redistribution in soil supporting photosynthesis over prolonged periods of drought. In particular, the presence of different rooting systems generates localized hydraulic redistribution fluxes that sustain understory transpiration through overstory-understory interactions. Such complex SPA dynamics cannot be properly summarized by equivalent ecosystem-scale Resistor-Capacitor (RC) rep- resentation. However our results show that, with proper averaging across water flow paths, RC models can provide reasonable estimates of stand-level water and carbon fluxes during inter-storm periods.« less

Hospital-acquired pressure ulcer prevalence--evaluating low-air-loss beds.

PubMed

Johnson, Jane; Peterson, Darcie; Campbell, Betty; Richardson, Regina; Rutledge, Dana

2011-01-01

Higher-category pressure redistribution mattresses are considered a critical component of a pressure ulcer prevention program, but few studies have quantified the impact of specific preventive measures on the incidence or prevalence of hospital-acquired pressure ulcers (HAPUs). Therefore, this study was undertaken to determine the impact of low-air-loss beds on HAPU prevalence. This prospective, comparative cohort study monitored the prevalence of HAPU at our hospital and compared rates of matched medical-surgical units with and without low-air-loss beds. Units without low-air-loss beds used a variety of alternative pressure redistribution devices for patients deemed at risk for pressure ulceration. The prevalence of HAPU was operationally defined as the number of patients with HAPUs divided by numbers of patients observed. The prevalence of HAPU over 3 quarters in 2008 ranged from 1.0% to 3.3% (overall rate 2.4%). Eighty-three percent of patients with HAPUs were cared for on low-air-loss beds. Of 12 patients with 16 HAPUs during this time, 75% were aged 70 years or older and 25% were managed in critical care units. Over half of patients who developed HAPUs had been hospitalized for 20 days or more. Half of the patients with HAPUs were scored as no-low risk on the Braden Scale.On the paired medical-surgical units, no statistically significant differences were found when patients with low-air-loss beds were compared to standard hospital mattresses supplemented by a variety of pressure redistribution devices. Seven of 11 HAPUs (63%) occurred in patients placed on low-air-loss beds. The prevalence of HAPU in patients placed on low-air-loss beds was no different from patients placed on standard hospital mattresses supplemented by a variety of pressure redistribution devices. Further research is needed to determine the impact of specific strategies on prevention of HAPU.

The impact of soil erosion on soil fertility and vine vigor. A multidisciplinary approach based on field, laboratory and remote sensing approaches.

PubMed

Novara, Agata; Pisciotta, Antonino; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Cerdà, Artemi; Gristina, Luciano

2018-05-01

Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60cm depth. Soil was sampled every 10cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the pole height method which allowed mapping of the soil redistribution. The vigor of vegetation, expressed as Normalized Difference Vegetation Index (NDVI), derived from high-resolution satellite multispectral data, was compared with measured pruning weight. Results confirmed that soil erosion, sediment redistribution and SOC across the slope was strongly affected by topographic features, slope and curvature. The erosion rate was 16Mgha -1 y -1 since the time of planting (6years). SOC redistribution was strongly correlated with the detachment or deposition areas as highlighted by pole height measurements. The off-farm SOC loss over six years amounted to 1.2MgCha -1 . SUVA 254 values, which indicate hydrophobic material rich in aromatic constituents of WEOC, decreased significantly along the slope, demonstrating that WEOC in the detachment site is more stable in comparison to deposition sites. The plant vigor was strongly correlated with WEOC constituents. Results demonstrated that high resolution passive remote sensing data combined with soil and plant analyses can survey areas with contrasting SOC, soil fertility, soil erosion and plant vigor. This will allow monitoring of soil erosion and degradation risk areas and support decision-makers in developing measures for friendly environmental management. Copyright © 2017 Elsevier B.V. All rights reserved.

Photoinduced diffusion molecular transport

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

Rozenbaum, Viktor M., E-mail: vik-roz@mail.ru, E-mail: litrakh@gmail.com; Dekhtyar, Marina L.; Lin, Sheng Hsien

2016-08-14

We consider a Brownian photomotor, namely, the directed motion of a nanoparticle in an asymmetric periodic potential under the action of periodic rectangular resonant laser pulses which cause charge redistribution in the particle. Based on the kinetics for the photoinduced electron redistribution between two or three energy levels of the particle, the time dependence of its potential energy is derived and the average directed velocity is calculated in the high-temperature approximation (when the spatial amplitude of potential energy fluctuations is small relative to the thermal energy). The thus developed theory of photoinduced molecular transport appears applicable not only to conventionalmore » dichotomous Brownian motors (with only two possible potential profiles) but also to a much wider variety of molecular nanomachines. The distinction between the realistic time dependence of the potential energy and that for a dichotomous process (a step function) is represented in terms of relaxation times (they can differ on the time intervals of the dichotomous process). As shown, a Brownian photomotor has the maximum average directed velocity at (i) large laser pulse intensities (resulting in short relaxation times on laser-on intervals) and (ii) excited state lifetimes long enough to permit efficient photoexcitation but still much shorter than laser-off intervals. A Brownian photomotor with optimized parameters is exemplified by a cylindrically shaped semiconductor nanocluster which moves directly along a polar substrate due to periodically photoinduced dipole moment (caused by the repetitive excited electron transitions to a non-resonant level of the nanocylinder surface impurity).« less

76 FR 62642 - Digital Broadcast Television Redistribution Control; Corrections

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-11

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 11-1432] Digital Broadcast Television Redistribution Control; Corrections AGENCY: Federal Communications Commission. ACTION: Technical amendment. SUMMARY: The Federal Communications Commission (FCC) is correcting a final rule that appeared in the...

Subsurface application enhances benefits of manure redistribution

USDA-ARS?s Scientific Manuscript database

Sustainable nutrient management requires redistribution of livestock manure from nutrient-excess areas to nutrient-deficit areas. Field experiments were conducted to assess agronomic (i.e., corn yield) and environmental (i.e., ammonia volatilization and surface nutrient losses) effects of different ...

Electrodiffusion kinetics of ionic transport in a simple membrane channel.

PubMed

Valent, Ivan; Petrovič, Pavol; Neogrády, Pavel; Schreiber, Igor; Marek, Miloš

2013-11-21

We employ numerical techniques for solving time-dependent full Poisson-Nernst-Planck (PNP) equations in 2D to analyze transient behavior of a simple ion channel subject to a sudden electric potential jump across the membrane (voltage clamp). Calculated spatiotemporal profiles of the ionic concentrations and electric potential show that two principal exponential processes can be distinguished in the electrodiffusion kinetics, in agreement with original Planck's predictions. The initial fast process corresponds to the dielectric relaxation, while the steady state is approached in a second slower exponential process attributed to the nonlinear ionic redistribution. Effects of the model parameters such as the channel length, height of the potential step, boundary concentrations, permittivity of the channel interior, and ionic mobilities on electrodiffusion kinetics are studied. Numerical solutions are used to determine spatiotemporal profiles of the electric field, ionic fluxes, and both the conductive and displacement currents. We demonstrate that the displacement current is a significant transient component of the total electric current through the channel. The presented results provide additional information about the classical voltage-clamp problem and offer further physical insights into the mechanism of electrodiffusion. The used numerical approach can be readily extended to multi-ionic models with a more structured domain geometry in 2D or 3D, and it is directly applicable to other systems, such as synthetic nanopores, nanofluidic channels, and nanopipettes.

Efficient ecologic and economic operational rules for dammed systems by means of nondominated sorting genetic algorithm II

NASA Astrophysics Data System (ADS)

Niayifar, A.; Perona, P.

2015-12-01

River impoundment by dams is known to strongly affect the natural flow regime and in turn the river attributes and the related ecosystem biodiversity. Making hydropower sustainable implies to seek for innovative operational policies able to generate dynamic environmental flows while maintaining economic efficiency. For dammed systems, we build the ecological and economical efficiency plot for non-proportional flow redistribution operational rules compared to minimal flow operational. As for the case of small hydropower plants (e.g., see the companion paper by Gorla et al., this session), we use a four parameters Fermi-Dirac statistical distribution to mathematically formulate non-proportional redistribution rules. These rules allocate a fraction of water to the riverine environment depending on current reservoir inflows and storage. Riverine ecological benefits associated to dynamic environmental flows are computed by integrating the Weighted Usable Area (WUA) for fishes with Richter's hydrological indicators. Then, we apply nondominated sorting genetic algorithm II (NSGA-II) to an ensemble of non-proportional and minimal flow redistribution rules in order to generate the Pareto frontier showing the system performances in the ecologic and economic space. This fast and elitist multiobjective optimization method is eventually applied to a case study. It is found that non-proportional dynamic flow releases ensure maximal power production on the one hand, while conciliating ecological sustainability on the other hand. Much of the improvement in the environmental indicator is seen to arise from a better use of the reservoir storage dynamics, which allows to capture, and laminate flood events while recovering part of them for energy production. In conclusion, adopting such new operational policies would unravel a spectrum of globally-efficient performances of the dammed system when compared with those resulting from policies based on constant minimum flow releases.

Viral Proteinase Requirements for the Nucleocytoplasmic Relocalization of Cellular Splicing Factor SRp20 during Picornavirus Infections

PubMed Central

Fitzgerald, Kerry D.; Chase, Amanda J.; Cathcart, Andrea L.; Tran, Genevieve P.

2013-01-01

Infection of mammalian cells by picornaviruses results in the nucleocytoplasmic redistribution of certain host cell proteins. These viruses interfere with import-export pathways, allowing for the cytoplasmic accumulation of nuclear proteins that are then available to function in viral processes. We recently described the cytoplasmic relocalization of cellular splicing factor SRp20 during poliovirus infection. SRp20 is an important internal ribosome entry site (IRES) trans-acting factor (ITAF) for poliovirus IRES-mediated translation; however, it is not known whether other picornaviruses utilize SRp20 as an ITAF and direct its cytoplasmic relocalization. Also, the mechanism by which poliovirus directs the accumulation of SRp20 in the cytoplasm of the infected cell is currently unknown. Work described in this report demonstrated that infection by another picornavirus (coxsackievirus B3) causes SRp20 to relocalize from the nucleus to the cytoplasm of HeLa cells, similar to poliovirus infection; however, SRp20 is relocalized to a somewhat lesser extent in the cytoplasm of HeLa cells during infection by yet another picornavirus (human rhinovirus 16). We show that expression of poliovirus 2A proteinase is sufficient to cause the nucleocytoplasmic redistribution of SRp20. Following expression of poliovirus 2A proteinase in HeLa cells, we detect cleavage of specific nuclear pore proteins known to be cleaved during poliovirus infection. We also find that expression of human rhinovirus 16 2A proteinase alone can cause efficient cytoplasmic relocalization of SRp20, despite the lower levels of SRp20 relocalization observed during rhinovirus infection compared to poliovirus. Taken together, these results further define the mechanism of SRp20 cellular redistribution during picornavirus infections, and they provide additional insight into some of the differences observed between human rhinovirus and other enterovirus infections. PMID:23255796

Resource selection by elk in an agro-forested landscape of northwestern Nebraska.

PubMed

Baasch, David M; Fischer, Justin W; Hygnstrom, Scott E; VerCauteren, Kurt C; Tyre, Andrew J; Millspaugh, Joshua J; Merchant, James W; Volesky, Jerry D

2010-11-01

In recent years, elk have begun recolonizing areas east of the Rocky Mountains that are largely agro-forested ecosystems composed of privately owned land where management of elk is an increasing concern due to crop and forage depredation and interspecific disease transmission. We used a Geographic Information System, elk use locations (n = 5013), random locations (n = 25,065), discrete-choice models, and information-theoretic methods to test hypotheses about elk resource selection in an agro-forested landscape located in the Pine Ridge region of northwestern Nebraska, USA. Our objectives were to determine landscape characteristics selected by female elk and identify publicly owned land within the Pine Ridge for potential redistribution of elk. We found distance to edge of cover influenced selection of resources by female elk most and that in areas with light hunting pressure, such as ours, this selection was not driven by an avoidance of roads. Female elk selected resources positioned near ponderosa pine cover types during all seasons, exhibited a slight avoidance of roads during spring and fall, selected areas with increased slope during winter and spring, and selected north- and east-facing aspects over flat areas and areas with south-facing slopes during winter months. We used our models to identified a potential elk redistribution area that had a higher proportion of landcover with characteristics selected by elk in our study area than the current herd areas and more landcover that was publicly owned. With appropriate management plans, we believe elk within the Potential Elk Redistribution Area would predominantly occupy publicly owned land, which would help minimize crop and forage damage on privately owned lands.

Resource Selection by Elk in an Agro-Forested Landscape of Northwestern Nebraska

NASA Astrophysics Data System (ADS)

Baasch, David M.; Fischer, Justin W.; Hygnstrom, Scott E.; Vercauteren, Kurt C.; Tyre, Andrew J.; Millspaugh, Joshua J.; Merchant, James W.; Volesky, Jerry D.

2010-11-01

In recent years, elk have begun recolonizing areas east of the Rocky Mountains that are largely agro-forested ecosystems composed of privately owned land where management of elk is an increasing concern due to crop and forage depredation and interspecific disease transmission. We used a Geographic Information System, elk use locations ( n = 5013), random locations ( n = 25,065), discrete-choice models, and information-theoretic methods to test hypotheses about elk resource selection in an agro-forested landscape located in the Pine Ridge region of northwestern Nebraska, USA. Our objectives were to determine landscape characteristics selected by female elk and identify publicly owned land within the Pine Ridge for potential redistribution of elk. We found distance to edge of cover influenced selection of resources by female elk most and that in areas with light hunting pressure, such as ours, this selection was not driven by an avoidance of roads. Female elk selected resources positioned near ponderosa pine cover types during all seasons, exhibited a slight avoidance of roads during spring and fall, selected areas with increased slope during winter and spring, and selected north- and east-facing aspects over flat areas and areas with south-facing slopes during winter months. We used our models to identified a potential elk redistribution area that had a higher proportion of landcover with characteristics selected by elk in our study area than the current herd areas and more landcover that was publicly owned. With appropriate management plans, we believe elk within the Potential Elk Redistribution Area would predominantly occupy publicly owned land, which would help minimize crop and forage damage on privately owned lands.

Sediment redistributed by coastal marsh mosquito ditching in Cape May County, New Jersey, U.S.A.

USGS Publications Warehouse

Kirby, Ronald E.; Widjeskog, Lee E.

2013-01-01

Effects of mosquito ditching on salt marsh sediment budgets have not been quantified for lack of sufficient records, but such information is necessary to provide historical context for current management objectives. We were able to do so in Cape May County New Jersey where Mosquito Extermination Commission records reported 1,493,900 m3 of spoil redistributed through ditching from1902 to 1974. The amount of spoil redistributed rose to 2,240,850 m3–22,987,800 m3 overall when ditch cleaning efforts were included. On a 54 km2 study area, 161,560 m of ditches removed as much as 99,000 m3 of material. If all such sediment stayed in the system and was deposited in open water, it would have added 0.082 mm/yr to those areas. If the sediments had accumulated only in the larger water bodies, it would have been sufficient to add 0.16 mm/yr to those areas. Alternatively, if the material had been deposited only on the marsh surface, the material displaced by mosquito ditching was capable of adding only 0.036 mm/yr. These rates are inconsequential in a system infilling at a rate of 4.4–7.4 mm/yr. Materials released by mosquito ditching thus have added to the sediment budgets of this coastal system, but shoaling of bays and sounds in recent centuries is a consequence of increases in all sediment sources including many of anthropogenic origin. Nonetheless, other consequences of ditching to the marsh (e.g., increased drainage, transport of water, and erosion of ditch banks) are not negligible in consideration of all anthropogenic effects. These data can help parameterize models of salt marsh accretion in the face of climate change.

Fluorescence intermittency originates from reclustering in two-dimensional organic semiconductors

DOE PAGES

Ruth, Anthony; Hayashi, Michitoshi; Zapol, Peter; ...

2017-02-22

Fluorescence intermittency or blinking is observed in nearly all nanoscale fluorophores. It is characterized by universal power-law distributions in on- and off-times as well as 1/f behaviour in corresponding emission power spectral densities. Blinking, previously seen in confined zero- and one-dimensional systems has recently been documented in two-dimensional reduced graphene oxide. Here we show that unexpected blinking during graphene oxide-to-reduced graphene oxide photoreduction is attributed, in large part, to the redistribution of carbon sp 2 domains. This reclustering generates fluctuations in the number/size of emissive graphenic nanoclusters wherein multiscale modelling captures essential experimental aspects of reduced graphene oxide’s absorption/emission trajectories,more » while simultaneously connecting them to the underlying photochemistry responsible for graphene oxide’s reduction. These simulations thus establish causality between currently unexplained, long timescale emission intermittency in a quantum mechanical fluorophore and identifiable chemical reactions that ultimately lead to switching between on and off states.« less

Controlled atmosphere annealing of ion implanted gallium arsenide. Final report 1 Jul 76-30 Nov 79

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

Anderson, C.L.; Eu, V.; Feng, M.

1980-08-01

Controlled atmosphere techniques were developed as an alternative to dielectric encapsulation for the high temperature anneal of ion implanted layers in GaAs. Two approaches: (1) the controlled atmosphere technique (CAT), and (2) the melt controlled ambient technique (MCAT) have been investigated. Using the CAT procedure, which involves annealing in flowing hydrogen with an arsenic overpressure, annealing without detectable surface erosion, has been performed at temperatures as high as 950 C, with or without encapsulants. Impurity diffusion, damage recovery, and electrical activity were investigated as a function of anneal parameters. Range studies of technologically important impurities such as S, Si, Se,more » Be and Mg were carried out. For the first time the role of the encapsulant on implanted profile degradation and the importance of Cr redistribution during the anneal cycle were determined. An improved CAT anneal system capable of production quantity throughput was developed and is in current use for device processing.« less

Accumulation patterns around Dome C, East Antarctica, in the last 73 kyr

NASA Astrophysics Data System (ADS)

Cavitte, Marie G. P.; Parrenin, Frédéric; Ritz, Catherine; Young, Duncan A.; Van Liefferinge, Brice; Blankenship, Donald D.; Frezzotti, Massimo; Roberts, Jason L.

2018-04-01

We reconstruct the pattern of surface accumulation in the region around Dome C, East Antarctica, since the last glacial. We use a set of 18 isochrones spanning all observable depths of the ice column, interpreted from various ice-penetrating radar surveys and a 1-D ice flow model to invert for accumulation rates in the region. The shallowest four isochrones are then used to calculate paleoaccumulation rates between isochrone pairs using a 1-D assumption where horizontal advection is negligible in the time interval of each layer. We observe that the large-scale (100s km) surface accumulation gradient is spatially stable through the last 73 kyr, which reflects current modeled and observed precipitation gradients in the region. We also observe small-scale (10 s km) accumulation variations linked to snow redistribution at the surface, due to changes in its slope and curvature in the prevailing wind direction that remain spatially stationary since the last glacial.

Notch sensitivity and stress redistribution in three ceramic-matrix composites

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

Mackin, T.J.; He, M.Y.; Evans, A.G.

Fiber-reinforced ceramic-matrix composites (CMCs) depend upon inelastic mechanisms to diffuse stress concentrations associated with holes, notches, and cracks. These mechanisms consist of fiber debonding and pullout, multiple matrix cracking, and shear band formation. In order to understand these effects, experiments have bee conducted on several double-edge-notched CMCs that exhibit different stress redistribution mechanisms. Stresses have been measured an d mechanisms identified by using a combination of methods including X0-ray imaging, edge replication, and thermoelastic analysis. Multiple matrix cracking was found to be the most effective stress redistribution mechanism.

Thermodynamics of cell adhesion. II. Freely mobile repellers.

PubMed Central

Torney, D C; Dembo, M; Bell, G I

1986-01-01

The equilibrium adhesion of a cell or vesicle to a substrate is analyzed in a theoretical model in which two types of mobile molecules in the cell membrane are of interest: receptors that can form bonds with fixed ligands in the substrate and repellers that repel the substrate. If the repulsion between the repeller molecule and substrate is greater than kT, there is substantial redistribution of the repellers from the contact area. Coexisting equilibrium states are observed having comparable free energies (a) with unstretched bonds and repeller redistribution and (b) with stretched bonds and partial redistribution. PMID:3955182

Extensions to decomposition of the redistributive effect of health care finance.

PubMed

Zhong, Hai

2009-10-01

The total redistributive effect (RE) of health-care finance has been decomposed into vertical, horizontal and reranking effects. The vertical effect has been further decomposed into tax rate and tax structure effects. We extend this latter decomposition to the horizontal and reranking components of the RE. We also show how to measure the vertical, horizontal and reranking effects of each component of the redistributive system, allowing analysis of the RE of health-care finance in the context of that system. The methods are illustrated with application to the RE of health-care financing in Canada.

Redistribution spurs growth by using a portfolio effect on risky human capital.

PubMed

Lorenz, Jan; Paetzel, Fabian; Schweitzer, Frank

2013-01-01

We demonstrate by mathematical analysis and systematic computer simulations that redistribution can lead to sustainable growth in a society. In accordance with economic models of risky human capital, we assume that dynamics of human capital is modeled as a multiplicative stochastic process which, in the long run, leads to the destruction of individual human capital. When agents are linked by fully redistributive taxation the situation might turn to individual growth in the long run. We consider that a government collects a proportion of income and reduces it by a fraction as costs for administration (efficiency losses). The remaining public good is equally redistributed to all agents. Sustainable growth is induced by redistribution despite the losses from the random growth process and despite administrative costs. Growth results from a portfolio effect. The findings are verified for three different tax schemes: proportional tax, taking proportionally more from the rich, and proportionally more from the poor. We discuss which of these tax schemes performs better with respect to maximize growth under a fixed rate of administrative costs, and the governmental income. This leads us to general conclusions about governmental decisions, the relation to public good games with free riding, and the function of taxation in a risk-taking society.

Coming full circle: 70 years of chronic lymphocytic leukemia cell redistribution, from glucocorticoids to inhibitors of B-cell receptor signaling

PubMed Central

Montserrat, Emili

2013-01-01

Chronic lymphocytic leukemia (CLL) cells proliferate in pseudofollicles within the lymphatic tissues, where signals from the microenvironment and BCR signaling drive the expansion of the CLL clone. Mobilization of tissue-resident cells into the blood removes CLL cells from this nurturing milieu and sensitizes them to cytotoxic drugs. This concept recently gained momentum after the clinical activity of kinase inhibitors that target BCR signaling (spleen tyrosine kinase, Bruton tyrosine kinase, PI3Kδ inhibitors) was established. Besides antiproliferative activity, these drugs cause CLL cell redistribution with rapid lymph node shrinkage, along with a transient surge in lymphocytosis, before inducing objective remissions. Inactivation of critical CLL homing mechanism (chemokine receptors, adhesion molecules), thwarting tissue retention and recirculation into the tissues, appears to be the basis for this striking clinical activity. This effect of BCR-signaling inhibitors resembles redistribution of CLL cells after glucocorticoids, described as early as in the 1940s. As such, we are witnessing a renaissance of the concept of leukemia cell redistribution in modern CLL therapy. Here, we review the molecular basis of CLL cell trafficking, homing, and redistribution and similarities between old and new drugs affecting these processes. In addition, we outline how these discoveries are changing our understanding of CLL biology and therapy. PMID:23264597

Redistribution Spurs Growth by Using a Portfolio Effect on Risky Human Capital

PubMed Central

Lorenz, Jan; Paetzel, Fabian; Schweitzer, Frank

2013-01-01

We demonstrate by mathematical analysis and systematic computer simulations that redistribution can lead to sustainable growth in a society. In accordance with economic models of risky human capital, we assume that dynamics of human capital is modeled as a multiplicative stochastic process which, in the long run, leads to the destruction of individual human capital. When agents are linked by fully redistributive taxation the situation might turn to individual growth in the long run. We consider that a government collects a proportion of income and reduces it by a fraction as costs for administration (efficiency losses). The remaining public good is equally redistributed to all agents. Sustainable growth is induced by redistribution despite the losses from the random growth process and despite administrative costs. Growth results from a portfolio effect. The findings are verified for three different tax schemes: proportional tax, taking proportionally more from the rich, and proportionally more from the poor. We discuss which of these tax schemes performs better with respect to maximize growth under a fixed rate of administrative costs, and the governmental income. This leads us to general conclusions about governmental decisions, the relation to public good games with free riding, and the function of taxation in a risk-taking society. PMID:23390505

ORBIT modelling of fast particle redistribution induced by sawtooth instability

NASA Astrophysics Data System (ADS)

Kim, Doohyun; Podestà, Mario; Poli, Francesca; Princeton Plasma Physics Laboratory Team

2017-10-01

Initial tests on NSTX-U show that introducing energy selectivity for sawtooth (ST) induced fast ion redistribution improves the agreement between experimental and simulated quantities, e.g. neutron rate. Thus, it is expected that a proper description of the fast particle redistribution due to ST can improve the modelling of ST instability and interpretation of experiments using a transport code. In this work, we use ORBIT code to characterise the redistribution of fast particles. In order to simulate a ST crash, a spatial and temporal displacement is implemented as ξ (ρ , t , θ , ϕ) = ∑ξmn (ρ , t) cos (mθ + nϕ) to produce perturbed magnetic fields from the equilibrium field B-> , δB-> = ∇ × (ξ-> × B->) , which affect the fast particle distribution. From ORBIT simulations, we find suitable amplitudes of ξ for each ST crash to reproduce the experimental results. The comparison of the simulation and the experimental results will be discussed as well as the dependence of fast ion redistribution on fast ion phase space variables (i.e. energy, magnetic moment and toroidal angular momentum). Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

Thinning increases growth of 60-year-old cherry-maple stands in West Virginia

Treesearch

Neil I. Lamson; Neil I. Lamson

1985-01-01

In north-central West Virginia, previously unmanaged 60-year-old cherrymaple stands were thinned to 60 percent relative stand density. Thinning reduced mortality, redistributed growth onto fewer, larger stems, and increased individual tree growth. Five-year periodic basal-area growth per acre was 1.2 times greater in thinned stands than in unthinned stands. Periodic...

Direct picosecond time resolution of unimolecular reactions initiated by local mode excitation

NASA Technical Reports Server (NTRS)

Scherer, N. F.; Doany, F. E.; Zewail, A. H.; Perry, J. W.

1986-01-01

Attention is given to the first results of direct, picosec measurements of the Delta-nu(OH) 5 local mode transition of H2O2. These time-resolved studies yield a direct measure of the unimolecular dissociation rate, and furnish a lower limit for the rate of energy redistribution from the OH stretch to the O-O reaction coordinate. The data thus determined may be used to ascertain the domain of validity for statistical unimolecular reaction rate theories.

Collaborative testing of turbulence models

NASA Technical Reports Server (NTRS)

Bradshaw, Peter; Launder, Brian E.; Lumley, John L.

1991-01-01

A review is given of an ongoing international project, in which data from experiments on, and simulations of, turbulent flows are distributed to developers of (time-averaged) engineering turbulence models. The predictions of each model are sent to the organizers and redistributed to all the modelers, plus some experimentalists and other experts (total approx. 120), for comment. The 'reaction time' of modelers has proved to be much longer than anticipated, partly because the comparisons with data have prompted many modelers to improve their models or numerics.

Real-time monitoring of metabolic function in liver-on-chip microdevices tracks the dynamics of mitochondrial dysfunction

PubMed Central

Bavli, Danny; Prill, Sebastian; Ezra, Elishai; Levy, Gahl; Cohen, Merav; Vinken, Mathieu; Vanfleteren, Jan; Jaeger, Magnus; Nahmias, Yaakov

2016-01-01

Microfluidic organ-on-a-chip technology aims to replace animal toxicity testing, but thus far has demonstrated few advantages over traditional methods. Mitochondrial dysfunction plays a critical role in the development of chemical and pharmaceutical toxicity, as well as pluripotency and disease processes. However, current methods to evaluate mitochondrial activity still rely on end-point assays, resulting in limited kinetic and prognostic information. Here, we present a liver-on-chip device capable of maintaining human tissue for over a month in vitro under physiological conditions. Mitochondrial respiration was monitored in real time using two-frequency phase modulation of tissue-embedded phosphorescent microprobes. A computer-controlled microfluidic switchboard allowed contiguous electrochemical measurements of glucose and lactate, providing real-time analysis of minute shifts from oxidative phosphorylation to anaerobic glycolysis, an early indication of mitochondrial stress. We quantify the dynamics of cellular adaptation to mitochondrial damage and the resulting redistribution of ATP production during rotenone-induced mitochondrial dysfunction and troglitazone (Rezulin)-induced mitochondrial stress. We show troglitazone shifts metabolic fluxes at concentrations previously regarded as safe, suggesting a mechanism for its observed idiosyncratic effect. Our microfluidic platform reveals the dynamics and strategies of cellular adaptation to mitochondrial damage, a unique advantage of organ-on-chip technology. PMID:27044092

Insights into Evaporative Droplet Dynamics in the High-Wind Atmospheric Boundary Layer

NASA Astrophysics Data System (ADS)

Peng, T.; Richter, D. H.

2017-12-01

Sea-spray droplets ejected into the air-sea boundary layer take part in a series of complex transport processes. To model the air-sea exchange of heat and moisture under high-wind conditions, it is important yet challenging to understand influences of evaporative droplets in the atmospheric boundary layer. We implement a high-resolution Eulerian-Lagrangian algorithm with droplets laden in a turbulent open-channel flow to reveal the dynamic and thermodynamic characteristics of evaporating sea spray. Our past numerical simulations demonstrated an overall weak modification to the total heat flux by evaporative droplets. This is due to redistributed sensible and latent heat fluxes from relatively small droplets that respond rapidly to the ambient environment or the limited residence time of larger droplets. However, droplets with a slower thermodynamic response to the environment indicate a potential to enhance the total heat flux, but this is dependent on concentration and suspension time. In the current study, we focus on correlations between the residence time and thermodynamic statistics of droplets in order to better understand how best to parameterize in large-scale models. In addition, we focus in detail on the different scales of turbulence to further characterize the range of influence that evaporating droplets have on the surrounding fluid.

Thermal energy and charge currents in multi-terminal nanorings

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

Kramer, Tobias; Konrad-Zuse-Zentrum für Informationstechnik Berlin, 14195 Berlin; Kreisbeck, Christoph

2016-06-15

We study in experiment and theory thermal energy and charge transfer close to the quantum limit in a ballistic nanodevice, consisting of multiply connected one-dimensional electron waveguides. The fabricated device is based on an AlGaAs/GaAs heterostructure and is covered by a global top-gate to steer the thermal energy and charge transfer in the presence of a temperature gradient, which is established by a heating current. The estimate of the heat transfer by means of thermal noise measurements shows the device acting as a switch for charge and thermal energy transfer. The wave-packet simulations are based on the multi-terminal Landauer-Büttiker approachmore » and confirm the experimental finding of a mode-dependent redistribution of the thermal energy current, if a scatterer breaks the device symmetry.« less

Incomplete Spontaneous Recovery from Airway Obstruction During Inhaled Anesthesia Induction: A Computational Simulation.

PubMed

Kuo, Alexander S; Vijjeswarapu, Mary A; Philip, James H

2016-03-01

Inhaled induction with spontaneous respiration is a technique used for difficult airways. One of the proposed advantages is if airway patency is lost, the anesthetic agent will spontaneously redistribute until anesthetic depth is reduced and airway patency can be recovered. There are little and conflicting clinical or experimental data regarding the kinetics of this anesthetic technique. We used computer simulation to investigate this situation. We used GasMan, a computer simulation of inhaled anesthetic kinetics. For each simulation, alveolar ventilation was initiated with a set anesthetic induction concentration. When the vessel-rich group level reached the simulation specified airway obstruction threshold, alveolar ventilation was set at 0 to simulate complete airway obstruction. The time until the vessel-rich group anesthetic level decreased below the airway obstruction threshold was designated time to spontaneous recovery. We varied the parameters for each simulation, exploring the use of sevoflurane and halothane, airway obstruction threshold from 0.5 to 2 minimum alveolar concentration (MAC), anesthetic induction concentration 2 to 4 MAC sevoflurane and 4 to 6 MAC halothane, cardiac output 2.5 to 10 L/min, functional residual capacity 1.5 to 3.5 L, and relative vessel-rich group perfusion 67% to 85%. In each simulation, there were 3 general phases: anesthetic wash-in, obstruction and overshoot, and then slow redistribution. During the first 2 phases, there was a large gradient between the alveolar and vessel-rich group. Alveolar do not reflect vessel-rich group anesthetic levels until the late third phase. Time to spontaneous recovery varied between 35 and 749 seconds for sevoflurane and 13 and 222 seconds for halothane depending on the simulation parameters. Halothane had a faster time to spontaneous recovery because of the lower alveolar gradient and less overshoot of the vessel-rich group, not faster redistribution. Higher airway obstruction thresholds, decreased anesthetic induction, and higher cardiac output reduced time to spontaneous recovery. To a lesser effect, decreased functional residual capacity and the decreased relative vessel-rich groups' perfusion also reduced the time to spontaneous recovery. Spontaneous recovery after complete airway obstruction during inhaled induction is plausible, but the recovery time is highly variable and depends on the clinical and physiologic situation. These results emphasize that induction is a non-steady-state situation, thus effect-site anesthetic levels should be modeled in future research, not alveolar concentration. Finally, this study provides an example of using computer simulation to explore situations that are difficult to investigate clinically.

HYDRAULIC REDISTRIBUTION IN THE PACIFIC NORTHWEST: TWEAKING THE SYSTEM

EPA Science Inventory

Hydraulic redistribution (HR) has recently been documented in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the soil-root system to tease apart ...

Are Ring Current Ions Lost in Electromagnetic Ion Cyclotron Wave Dispersion Relation?

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Gamayunov, K. V.

2006-01-01

Electromagnetic ion cyclotron (EMIC) waves are widely observed in the inner and outer magnetosphere, at geostationary orbit, at high latitudes along the plasmapause, and at the ionospheric altitudes. Interaction of the Ring Current (RC) ions and EMIC waves causes ion scattering into the loss cone and leads to decay of the RC, especially during the main phase of storms when the RC decay times of about one hour or less are observed. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Induced scattering of these waves by the plasmaspheric thermal ions leads to ion temperature enhancement, and forms a so-called hot zone near the plasmapause where the temperature of core plasma ions can reach tens of thousands of degrees. Relativistic electrons in the outer radiation belt also interact well with the EMIC waves, and during the main and/or recovery phases of the storms these electrons can easily be scattered into the loss cone over a time scale from several hours to a day. The plasma density distribution in the magnetosphere and the ion content play a critical role in EMIC wave generation and propagation, but the wave dispersion relation in the known RC-EMIC wave interaction models is assumed to be determined by the thermal plasma distribution only. In these models, the modification of the EMIC wave dispersion relation caused by the RC ions is not taken into account, and the RC ions are only treated as a source of free energy in order to generate EMIC waves. At the same time, the RC ions can dominate the thermal magnetospheric content in the night MLT sector at great L shells during the main and/or recovery storm phase. In this study, using our self-consistent RC-EMIC wave model [Khazanov et al., 2006], we simulate the May 1998 storm in order to quantify the global EMIC wave redistribution caused by taking into account the RC ions in the EMIC wave dispersion relation. The dramatic wave pattern redistribution is observed in the postdusk-predawn MLT sector (night sector) for L greater than 5. We found the intense EMIC waves (about a few nT) there during the main and early recovery phases of the storm. The observed wave generation in this sector is caused by taking into account the EMIC wave dispersion change due to the RC ions. There are no waves at these locations in our model if the RC ions are taken into account in the wave growth rate only, and the wave dispersion relation is only governed by the thermal plasmaspheric model.

Effect of Ring Current Ions on Electromagnetic Ion Cyclotron Wave Dispersion Relation

NASA Technical Reports Server (NTRS)

Gamayunov, K. V.; Khazanov, G. V.

2006-01-01

Electromagnetic ion cyclotron (EMIC) waves are widely observed in the inner and outer magnetosphere, at geostationary orbit, at high latitudes along the plasmapause, and at the ionospheric altitudes. Interaction of the Ring Current (RC) ions and EMIC waves causes ion scattering into the loss cone and leads to decay of the RC, especially during the main phase of storms when the RC decay times of about one hour or less are observed. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Induced scattering of these waves by the plasmaspheric thermal ions leads to ion temperature enhancement, and forms a so-called hot zone near the plasmapause where the temperature of core plasma ions can reach tens of thousands of degrees. Relativistic electrons in the outer radiation belt also interact well with the EMIC waves, and during the main and/or recovery phases of the storms these electrons can easily be scattered into the loss cone over a time scale from several hours to a day. The plasma density distribution in the magnetosphere and the ion content play a critical role in EMIC wave generation and propagation, but the wave dispersion relation in the known RC-EMIC wave interaction models is assumed to be determined by the thermal plasma distribution only. In these models, the modification of the EMIC wave dispersion relation caused by the RC ions is not taken into account, and the RC ions are only treated as a source of free energy in order to generate EMIC waves. At the same time, the RC ions can dominate the thermal magnetospheric content in the night MLT sector at great L shells during the main and/or recovery storm phase. In this study, using our self-consistent RC-EMIC wave model [Khazanov et al., 2006], we simulate the May 1998 storm in order to quantify the global EMIC wave redistribution caused by taking into account the RC ions in the EMIC wave dispersion relation. The dramatic wave pattern redistribution is observed in the postdusk-predawn MLT sector (night sector) for L greater than 5. We found the intense EMIC waves (about a few nT) there during the main and early recovery phases of the storm. The observed wave generation in this sector is caused by taking into account the EMIC wave dispersion change due to the RC ions. There are no waves at these locations in our model if the RC ions are taken into account in the wave growth rate only, and the wave dispersion relation is only governed by the thermal plasmaspheric model.

Redistribution of fluorescently labeled tubulin in the mitotic apparatus of sand dollar eggs and the effects of taxol.

PubMed

Hamaguchi, Y; Toriyama, M; Sakai, H; Hiramoto, Y

1987-02-01

Fluorescently labeled tubulin was quickly incorporated into the mitotic apparatus when injected into a live sand dollar egg. After a rectangular area (1.6 X 16 microns) of the mitotic spindle was photobleached at metaphase or anaphase by the irradiation of a laser microbeam, redistribution of fluorescence was almost complete within 30 sec. The photobleached area did not change in shape during the redistribution. During the period of redistribution, the bleached area moved slightly toward the near pole at metaphase and anaphase (means: 1.6 and 1.8 micron/min, respectively). These results indicate that redistribution was not due to the exchange of tubulin subunits only at the ends of microtubules but to their rapid exchange at sites along the microtubules in the bleached region. Furthermore, treadmilling of tubulin molecules along with the spindle microtubules possibly occurred at the rate of 1.6 micron/min at metaphase. Birefringence of the mitotic apparatus increased with a large increase in both the number and length of astral rays shortly after taxol was injected. However, the microtubules did not all seem to elongate at the same rate but appeared to become equalized in length. Chromosome movement stopped within 60 sec after the injection. Centrospheres became large and the labeled tubulin already incorporated into the centrospheres was excluded from the enlarged centrospheres. Shortly after the labeled tubulin was injected following the injection of taxol, it accumulated in the peripheral region of the centrospheres, suggesting that microtubules first assembled at this region. Fluorescently labeled tubulin in the mitotic apparatus in the egg after injection of taxol was redistributed much more slowly after photobleaching than in uninjected eggs.

Household perceptions towards a redistributive policy across health insurance funds in Tanzania.

PubMed

Chomi, Eunice N; Mujinja, Phares G M; Hansen, Kristian; Kiwara, Angwara D; Enemark, Ulrika

2015-03-15

The Tanzanian health insurance system comprises multiple health insurance funds targeting different population groups but which operate in parallel, with no mechanisms for redistribution across the funds. Establishing such redistributive mechanisms requires public support, which is grounded on the level of solidarity within the country. The aim of this paper is to analyse the perceptions of CHF, NHIF and non-member households towards cross-subsidisation of the poor as an indication of the level of solidarity and acceptance of redistributive mechanisms. This study analyses data collected from a survey of 695 households relating to perceptions of household heads towards cross-subsidisation of the poor to enable them to access health services. Kruskal-Wallis test is used to compare perceptions by membership status. Generalized ordinal logistic regression models are used to identify factors associated with support for cross-subsidisation of the poor. Compared to CHF and NHIF households, non-member households expressed the highest support for subsidised CHF membership for the poor. The odds of expressing support for subsidised CHF membership are higher for NHIF households and non-member households, households that are wealthier, whose household heads have lower education levels, and have sick members. The majority of households support a partial rather than fully subsidised CHF membership for the poor and there were no significant differences by membership status. The odds of expressing willingness to contribute towards subsidised CHF membership are higher for households that are wealthier, with young household heads and have confidence in scheme management. The majority may support a redistributive policy, but there are indications that this support and willingness to contribute to its achievement are influenced by the perceived benefits, amount of subsidy considered, and trust in scheme management. These present important issues for consideration when designing redistributive policies.

Intrahepatic Flow Redistribution in Patients Treated with Radioembolization

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

Spreafico, Carlo, E-mail: carlo.spreafico@istitutotumori.mi.it; Morosi, Carlo, E-mail: carlo.morosi@istitutotumori.mi.it; Maccauro, Marco, E-mail: marco.maccauro@istitutotumori.mi.it

2015-04-15

IntroductionIn planning Yttrium-90 ({sup 90}Y)-radioembolizations, strategy problems arise in tumours with multiple arterial supplies. We aim to demonstrate that tumours can be treated via one main feeding artery achieving flow redistribution by embolizing accessory vessels.MethodsOne hundred {sup 90}Y-radioembolizations were performed on 90 patients using glass microspheres. In 19 lesions/17 patients, accessory branches were found feeding a minor tumour portion and embolized. In all 17 patients, the assessment of the complete perfusion was obtained by angiography and single photon emission computerized tomography–computerized tomography (SPECT–CT). Dosimetry, toxicity, and tumor response rate of the patients treated after flow redistribution were compared with themore » 83 standard-treated patients. Seventeen lesions in 15 patients with flow redistribution were chosen as target lesions and evaluated according to mRECIST criteria.ResultsIn all patients, the complete tumor perfusion was assessed immediately before radioembolization by angiography in all patients and after the {sup 90}Y-infusion by SPECT–CT in 15 of 17 patients. In the 15 assessable patients, the response rate in their 17 lesions was 3 CR, 8 PR, and 6 SD. Dosimetric and toxicity data, as well tumour response rate, were comparable with the 83 patients with regular vasculature.ConclusionsAll embolization procedures were performed successfully with no complications, and the flow redistribution was obtained in all cases. Results in term of toxicity, median dose administered, and radiological response were comparable with standard radioembolizations. Our findings confirmed the intratumoral flow redistribution after embolizing the accessory arteries, which makes it possible to treat the tumour through its single main feeding artery.« less

CXCR2 inverse agonism detected by arrestin redistribution.

PubMed

Kredel, Simone; Wolff, Michael; Wiedenmann, Jörg; Moepps, Barbara; Nienhaus, G Ulrich; Gierschik, Peter; Kistler, Barbara; Heilker, Ralf

2009-10-01

To study CXCR2 modulated arrestin redistribution, the authors employed arrestin as a fusion protein containing either the Aequorea victoria-derived enhanced green fluorescent protein (EGFP) or a recently developed mutant of eqFP611, a red fluorescent protein derived from Entacmaea quadricolor. This mutant, referred to as RFP611, had earlier been found to assume a dimeric quarternary structure. It was therefore employed in this work as a "tandem" (td) construct for pseudo-monomeric fusion protein labeling. Both arrestin fusion proteins, containing either td-RFP611 (Arr-td-RFP611) or enhanced green fluorescent protein (EGFP; Arr-EGFP), were found to colocalize with internalized fluorescently labeled Gro-alpha a few minutes after Gro-alpha addition. Intriguingly, however, Arr-td-RFP611 and Arr-EGFP displayed distinct cellular distribution patterns in the absence of any CXCR2-activating ligand. Under these conditions, Arr-td-RFP611 showed a largely homogeneous cytosolic distribution, whereas Arr-EGFP segregated, to a large degree, into granular spots. These observations indicate a higher sensitivity of Arr EGFP to the constitutive activity of CXCR2 and, accordingly, an increased arrestin redistribution to coated pits and endocytic vesicles. In support of this interpretation, the authors found the known CXCR2 antagonist Sch527123 to act as an inverse agonist with respect to Arr-EGFP redistribution. The inverse agonistic properties of Sch527123 were confirmed in vitro in a guanine nucleotide binding assay, revealing an IC(50) value similar to that observed for Arr-EGFP redistribution. Thus, the redistribution assay, when based on Arr-EGFP, enables the profiling of antagonistic test compounds with respect to inverse agonism. When based on Arr-td-RFP611, the assay may be employed to study CXCR2 agonism or neutral antagonism.

Dynamics of Soil Organic Carbon and Microbial Biomass Carbon in Relation to Water Erosion and Tillage Erosion

PubMed Central

Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

2013-01-01

Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the 137Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of 137Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. 137Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the <0.002-mm clay shows that water erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion. PMID:23717530

Offshore oil and gas activity impact. Hearings before the Committee on Energy and Natural Resources, US Senate, One Hundred Sixth Congress, First Session, January 27, 1999

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

NONE

1999-07-01

The purpose of this hearing is hear of the impacts of offshore exploration and production activities on coastal states and communities as it relates to Senate Bill 25. This bill would remedy current inequities by redistributing 50 percent of the Outer Continental Shelf (OCS) revenues to three programs: coastal impact assistance, local park and recreation, and wildlife programs. Statements were heard from representatives from three of the Gulf Coast States, as well as Alaska.

Pricing Medicare's diagnosis-related groups: Charges versus estimated costs

PubMed Central

Price, Kurt F.

1989-01-01

Hospital payments under Medicare's prospective payment system (PPS) are based on prices established for 474 diagnosis-related groups (DRG's). Previous analyses using 1981 data demonstrated that DRG prices based on charges alone were not that different from prices calculated from estimated costs. Data for 1986 were used in this study to show that the differences between the two sets of DRG prices are much larger than previously reported. If DRG prices were once again based on estimated costs instead of the current charge-based prices, payments would be significantly redistributed. PMID:10313356

Charge redistribution from novel magneto-vorticity coupling in anomalous hydrodynamics

NASA Astrophysics Data System (ADS)

Hattori, Koichi; Yin, Yi

2017-11-01

We discuss new transport phenomena in the presence of both a strong magnetic field and a vortex field. Their interplay induces a charge distribution and a current along the magnetic field. We show that the associated transport coefficients can be obtained from a simple analysis of the single-particle distribution functions and also from the Kubo formula calculation. The consistent results from these analyses suggest that the transport coefficients are tied to the chiral anomaly in the (1 + 1) dimension because of the dimensional reduction in the lowest Landau levels.

[The G-DRG System 2009--relevant changes for rheumatology].

PubMed

Fiori, W; Liedtke-Dyong, A; Lakomek, H-J; Buscham, K; Lehmann, H; Liman, W; Fuchs, A-K; Bessler, F; Roeder, N

2010-05-01

The following article presents the major general and specific changes in the G-DRG system, in the classification systems for diagnoses and procedures as well as for the billing process for 2010. Since the G-DRG system is primarily a tool for the redistribution of resources, every hospital needs to analyze the economic effects of the changes by applying the G-DRG transition-grouper to its own cases. Depending on their clinical focus, rheumatological departments may experience positive or negative consequences from the adjustments. In addition, relevant current case law is considered.

Seasonal air and water mass redistribution effects on LAGEOS and Starlette

NASA Technical Reports Server (NTRS)

Gutierrez, Roberto; Wilson, Clark R.

1987-01-01

Zonal geopotential coefficients have been computed from average seasonal variations in global air and water mass distribution. These coefficients are used to predict the seasonal variations of LAGEOS' and Starlette's orbital node, the node residual, and the seasonal variation in the 3rd degree zonal coefficient for Starlette. A comparison of these predictions with the observed values indicates that air pressure and, to a lesser extent, water storage may be responsible for a large portion of the currently unmodeled variation in the earth's gravity field.

IGS Data Flow

NASA Technical Reports Server (NTRS)

Noll, Carey

2006-01-01

The IGS analysis centers and user community in general need to be assured that the data centers archive a consistent set of files. Changes to the archives can occur because of the re-publishing of data, the transmission of historic data, and the resulting re-distribution (or lack thereof) of these data from data center to data center. To ensure the quality of the archives, a defined data flow and method of archive population needs to be established. This poster will diagram and review the current IGS data flow, discuss problems that have occurred, and provide recommendations for improvement.

An experimental study of subaqueous slipface deposition.

USGS Publications Warehouse

Hunter, R.E.; Kocurek, G.

1986-01-01

A flume study indicates that grainflow on slipfaces accounts for most cross-strata formed in unidirectional, shallow-water flows. The slipfaces studied were on small megaripples and delta-like steps (0.06-0.28 m high). During intermittent avalanching, at relatively low flow velocities, periods between avalanches were marked by grainfall onto the slipface, the intensity of which was greatest near the brink of the slipface and increased with current velocity. The lee eddy proved very significant in slipface processes by redistributing grainfall sediments and both promoting and impeding grainflow. -from Authors

ARM - Midlatitude Continental Convective Clouds

DOE Data Explorer

Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

2012-01-19

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

ARM - Midlatitude Continental Convective Clouds (comstock-hvps)

DOE Data Explorer

Jensen, Mike; Comstock, Jennifer; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

2012-01-06

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

Nanoscale Morphology Evolution Under Ion Irradiation

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

Aziz, Michael J.

We showed that the half-century-old paradigm of morphological instability under irradiation due to the curvature-dependence of the sputter yield, can account neither for the phase diagram nor the amplification or decay rates that we measure in the simplest possible experimental system -- an elemental semiconductor with an amorphous surface under noble-gas ion irradiation; We showed that a model of pattern formation based on the impact-induced redistribution of atoms that do not get sputtered away explains our experimental observations; We developed a first-principles, parameter-free approach for predicting morphology evolution, starting with molecular dynamics simulations of single ion impacts, lasting picoseconds, andmore » upscaling through a rigorous crater-function formalism to develop a partial differential equation that predicts morphology evolution on time scales more than twelve orders of magnitude longer than can be covered by the molecular dynamics; We performed the first quantitative comparison of the contributions to morphological instability from sputter removal and from impact-induced redistribution of atoms that are removed, and showed that the former is negligible compared to the latter; We established a new paradigm for impact-induced morphology evolution based on crater functions that incorporate both redistribution and sputter effects; and We developed a model of nanopore closure by irradiation-induced stress and irradiationenhanced fluidity, for the near-surface irradiation regime in which nuclear stopping predominates, and showed that it explains many aspects of pore closure kinetics that we measure experimentally.« less

Hydraulic redistribution by two semi-arid shrub species: Implications for Sahelianagro-ecosystems

EPA Science Inventory

Hydraulic redistribution is the process of passive water movement from deeper moist soil to shallower dry soil layers using plant roots as conduits. Results from this study indicate that this phenomenon exists among two shrub species (Guiera senegalensis and Piliostigma reticulat...

47 CFR 76.1909 - Redistribution control of unencrypted digital terrestrial broadcast content.

Code of Federal Regulations, 2011 CFR

2011-10-01

... content. Where a multichannel video programming distributor retransmits unencrypted digital terrestrial... 47 Telecommunication 4 2011-10-01 2011-10-01 false Redistribution control of unencrypted digital... (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Encoding Rules § 76.1909...

Redistribution, Recognition and Representation: Working against Pedagogies of Indifference

ERIC Educational Resources Information Center

Lingard, Bob; Keddie, Amanda

2013-01-01

This paper reports on an Australian government-commissioned research study that documented classroom pedagogies in 24 Queensland schools. The research created the model of "productive pedagogies", which conjoined what Nancy Fraser calls a politics of redistribution, recognition and representation. In this model pedagogies are…

Education, Meritocracy and Redistribution

ERIC Educational Resources Information Center

Souto-Otero, Manuel

2010-01-01

This paper analyses the relationship between education, meritocracy and redistribution. It first questions the meritocratic ideal highlighting how it relates to normative expectations that do not hold fully neither in their logic nor in practice. It then complements the literature on persistent inequalities by focusing on the opportunities for…

HYDRAULIC REDISTRIBUTION OF SOIL WATER: ECOSYSTEM IMPLICATIONS FOR PACIFIC NORTHWEST FORESTS

EPA Science Inventory

The physical process of hydraulic redistribution (HR) is driven by competing soil, tree and atmospheric water potential gradients, and may delay severe water stress for roots and other biota associated with the upper soil profile. We monitored soil moisture characteristics across...

CONTAMINANT REDISTRIBUTION CAN CONFOUND INTERPRETATION OF OIL-SPILL BIOREMEDIATION STUDIES

EPA Science Inventory

The physical redistribution of oil between the inside and outside of experimental plots can affect the results of bioremediation field studies that are conducted on shorelines contaminated by real oil spills. Because untreated oil from the surrounding beach will enter the plot, ...

Distribution of ferromanganese nodules in the Pacific Ocean.

USGS Publications Warehouse

Piper, D.Z.; Swint-Iki, T.R.; McCoy, F.W.

1987-01-01

The occurrence and distribution of deep-ocean ferromanganese nodules are related to the lithology of pelagic surface-sediment, sediment accumulation rates, sea-floor bathymetry, and benthic circulation. Nodules often occur in association with both biosiliceous and pelagic clay, and less often with calcareous sediment. Factors which influence the rather complex patterns of sediment lithology and accumulation rates include the supply of material to the sea-floor and secondary processes in the deep ocean which alter or redistribute that supply. The supply is largely controlled by: 1) proximity to a source of alumino-silicate material and 2) primary biological productivity in the photic zone of the ocean. Primary productivity controls the 'rain' to the sea-floor of biogenic detritus, which consists mostly of siliceous and calcareous tests of planktonic organisms but also contains smaller proportions of phosphatic material and organic matter. The high accumulation rate (5 mm/1000 yr) of sediment along the equator is a direct result of high productivity in this region of the Pacific. Secondary processes include the dissolution of particulate organic matter at depth in the ocean, notably CaCO3, and the redistribution of sedimentary particles by deep-ocean currents. -J.M.H.

Stress redistribution and damage in interconnects caused by electromigration

NASA Astrophysics Data System (ADS)

Chiras, Stefanie Ruth

Electromigration has long been recognized as a phenomenon that induces mass redistribution in metals which, when constrained, can lead to the creation of stress. Since the development of the integrated circuit, electromigration. in interconnects, (the metal lines which carry current between devices in integrated circuits), has become a reliability concern. The primary failure mechanism in the interconnects is usually voiding, which causes electrical resistance increases in the circuit. In some cases, however, another failure mode occurs, fracture of the surrounding dielectric driven by electromigration induced compressive stresses within the interconnect. It is this failure mechanism that is the focus of this thesis. To study dielectric fracture, both residual processing stresses and the development of electromigration induced stress in isolated, constrained interconnects was measured. The high-resolution measurements were made using two types of piezospectroscopy, complemented by finite element analysis (FEA). Both procedures directly measured stress in the underlying or neighboring substrate and used FEA to determine interconnect stresses. These interconnect stresses were related to the effected circuit failure mode through post-test scanning electron microscopy and resistance measurements taken during electromigration testing. The results provide qualitative evidence of electromigration driven passivation fracture, and quantitative analysis of the theoretical model of the failure, the "immortal" interconnect concept.

Redistribution of boron in leaves reduces boron toxicity

PubMed Central

Fitzpatrick, Kate L

2009-01-01

High soil boron (B) concentrations lead to the accumulation of B in leaves, causing the development of necrotic regions in leaf tips and margins, gradually extending back along the leaf. Plants vary considerably in their tolerance to B toxicity, and it was recently discovered that one of the tolerance mechanisms involved extrusion of B from the root. Expression of a gene encoding a root B efflux transporter was shown to be much higher in tolerant cultivars. In our current research we have shown that the same gene is also upregulated in leaves. However, unlike in the root, the increased activity of the B efflux transporter in the leaves cannot reduce the tissue B concentration. Instead, we have shown that in tolerant cultivars, these transporters redistribute B from the intracellular phase where it is toxic, into the apoplast which is much less sensitive to B. These results provide an explanation of why different cultivars with the same leaf B concentrations can show markedly different toxicity symptoms. We have also shown that rain can remove a large proportion of leaf B, leading to significant improvements of growth of both leaves and roots. PMID:20009556

Perfusion lung imaging in the adult respiratory distress syndrome

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

Pistolesi, M.; Miniati, M.; Di Ricco, G.

1986-07-01

In 29 perfusion lung scans (PLS) of 19 patients with ARDS, 20 of which were obtained within six days from the onset of respiratory symptoms, perfusion abnormalities were the rule. These included focal, nonsegmental defects, mostly peripheral and dorsal, and perfusion redistribution away from the dependent lung zones. PLS were scored for the presence and intensity of perfusion abnormalities and the scores of perfusion redistribution were validated against numerical indices of blood flow distribution per unit lung volume. PLS scores were correlated with arterial blood gas values, hemodynamic parameters, and chest radiographic scores of ARDS. Arterial oxygen tension correlated withmore » the scores of both perfusion defects and redistribution. Perfusion defects correlated better with the radiographic score of ARDS, and perfusion redistribution with PAP and vascular resistance. ARDS patients exhibit peculiar patterns of PLS abnormalities not observed in other disorders. Thus, PLS may help considerably in the detection and evaluation of pulmonary vascular injury in ARDS.« less

Extreme energetic particle decreases near geostationary orbit - A manifestation of current diversion within the inner plasma sheet

NASA Technical Reports Server (NTRS)

Baker, D. N.; Mcpherron, R. L.

1990-01-01

A qualitative model of magnetic field reconfiguration as might result from neutral line formation in the central plasma sheet late in a substorm growth phase is considered. It is suggested that magnetic reconnection probably begins before the substorm expansion phase and that cross-tail current is enhanced across the plasma sheet both earthward and tailward of a limited region near the neutral line. Such an enhanced cross-tail current earthward of the original X line region may contribute to thinning the plasma sheet substantially, and this would in turn affect the drift currents in that location, thus enhancing the current even closer toward the earth. In this way a redistribution and progressive diversion of normal cross-tail current throughout much of the inner portion of the plasma sheet could occur. The resulting intensified current, localized at the inner edge of the plasma sheet, would lead to a very thin plasma confinement region. This would explain the very taillike field and extreme particle dropouts often seen late in substorm growth phases.

Societal resilience to hydroclimatic change in the Roman World

NASA Astrophysics Data System (ADS)

Dermody, Brian; van Beek, Rens; Bierkens, Marc; Dekker, Stefan

2016-04-01

The Romans were masters of water resource management. They employed sophisticated irrigation techniques alongside a highly integrated food redistribution system that provided stable food supplies under the variable hydroclimatic regime within the Roman World. However, a number of paleoclimate studies have demonstrated hydroclimatic changes during the Roman Period that exceeded the amplitude and persistence of normal climate variability. In particular, there was a shift from warmer and more stable hydroclimatic conditions in the Roman Warm Period (c.250 BC - 250 AD) to cooler and more variable conditions in Late Roman Period (after c.250 AD). In this study we use a socio-hydrological model of the Roman world to explore the impact of hydroclimatic changes between the Roman Warm Period and Late Roman Period on the Roman food production and redistribution system. We calculate crop yields based on temperature and water resource availability using PC Raster Global Water Balance model (PCR-GLOBWB). PCR-GLOBWB is forced with reanalysis climate fields reflecting reconstructions of Roman Warm Period to the Late Roman climate patterns. Cropland areas and settlement patterns are derived from a database of 14,700 Roman settlement sites and crop suitability maps. We simulate food redistribution using a multi-agent food redistribution network with link weights based on Orbis: The Stanford Geospatial Network of the Roman World. Our analysis indicates a reduction in crop yields during the Late Roman Period compared with the Roman Warm Period owing to cooler temperatures. In addition, our simulations indicate that increased hydroclimatic variability decreased the stability of yields in the Late Roman period. Crop yields in the Western Empire are simulated to have been impacted most by the change in climate owing to cooler average temperatures and greater hydroclimatic variability compared with the Eastern part of the Empire. The food redistribution network was essential to buffer against lower and less stable yields in the Late Roman Period. However, the Late Roman Period coincided with a breakdown in the food redistribution network, making the Western Roman Empire particularly vulnerable to changing climate conditions. Our analysis demonstrates a number of important processes that have general implications for water resource management in food production and redistribution systems.

Effects of fluvial processes in different order river valleys on redistribution and storage of particle-bound radioactive caesium-137 in area of significant Chernobyl fallout and impact on linked rivers with lower contamination levels

NASA Astrophysics Data System (ADS)

Belyaev, Vladimir; Golosov, Valentin; Shamshurina, Evgeniya; Ivanov, Maxim; Ivanova, Nadezhda; Bezukhov, Dmitry; Onda, Yuichi; Wakiyama, Yoshifumi; Evrard, Olivier

2015-04-01

Detailed investigations of the post-fallout fate of radionuclide contamination represent an important task in terms of environmental quality assessment. In addition, particle-bound radionuclides such as the most widespread anthropogenic isotope caesium-137 can be used as tracers for quantitative assessment of different sediment redistribution processes. In landscapes of humid plains with agriculture-dominated land use the post-fallout redistribution of caesium-137 is primarily associated with fluvial activity of various scales in cascade systems starting from soil erosion on cultivated hillslopes through gully and small dry valley network into different order perennial streams and rivers. Our investigations in the so-called Plavsk hotspot (area of very high Chernobyl caesium-137 contamination within the Plava River basin, Tula Region, Central European Russia) has been continuing for more than 15 years by now, while the time passed since the Chernobyl disaster and associated radioactive fallout (1986) is almost 29 years. Detailed information on the fluvial sediment and associated caesium-137 redistribution has been obtained for case study sites of different size from individual cultivated slopes and small catchments of different size (2-180 km2) to the entire Plava River basin scale (1856 km2). It has been shown that most of the contaminated sediment over the time passed since the fallout has remained stored within the small dry valleys of the 1-4 Hortonian order and local reservoirs (>70%), while only about 5% reached the 5-6 order valleys (main tributaries of the Plava River) and storage of the Plava floodplain itself represents as low as 0.3% of the basin-scale total sediment production from eroded cultivated hillslopes. Nevertheless, it has been shown that contaminated sediment yield from the Plava River basin exerts significant influence on less polluted downstream-linked river system. Recent progress of the investigations involved sampling of 7 detailed depth-incremental floodplain sediment sections along the Upa River valley, which is the receiving river for the Plava and is characterized by generally much lower caesium-137 contamination within other parts of its basin. One of the sampled sections was located several kilometers upstream from the Plava River mouth and the other 6 - at different distances downstream starting from about 2 km to about 40 km. In this case we can assume the Plava River mouth to be the point-source of sediment-associated radioactive contamination additional to the initial fallout. It has been found that while at the nearest point downstream the floodplain sediment contamination by caesium-137 is about 2 order of magnitude higher, than upstream, it decreases quickly along the Upa River valley two about 3 times higher than upstream at the most remote downstream point. Importantly, the decrease is not represented by gradual and uniform curve. In contrast, it is interrupted by local increase caused by smaller tributary from relatively high contamination area. It is believed that the obtained information on decadal-scale sediment and associated post-fallout caesium-137 redistribution through the fluvial network, patterns of sinks and rate of contamination propagation into the less polluted downstream-linked river basin can be used for testing and improving the predictive models being developed for applications in other contaminated areas such as river basins around the Fukushima Daiichi nuclear power plant, providing that differences in landscape settings, hydrological regime and land use patterns are taken into account.

Nitrogen transformations in response to temperature and rainfall manipulation in oak savanna: A global change experiment

NASA Astrophysics Data System (ADS)

Wellman, R. L.; Boutton, T. W.; Tjoelker, M. G.; Volder, A.; Briske, D. D.

2013-12-01

Increasing concentrations of greenhouse gases are projected to elevate global surface air temperatures by 1.1 to 6.4°C by the end of the century, and potentially magnify the intensity and variability of seasonal precipitation distribution. The mid-latitude grasslands of North America are predicted to experience substantial modification in precipitation regimes, with a shift towards drier summers and wetter spring and fall seasons. Despite these predictions, little is known concerning the effects of these global climate change drivers or their potential interactive effects on nitrogen (N) cycling processes. The purpose of this study is to quantify seasonal variation in rates of N-mineralization, nitrification, and N-losses via leaching in soil subjected to experimental warming and rainfall manipulation. Research was conducted at the Texas A&M Warming and Rainfall Manipulation (WaRM) Site in College Station where eight 9x18m rainout shelters and two unsheltered controls were established in post oak savanna in 2003. Replicate annual rainfall redistribution treatments (n = 4) are applied at the shelter level (long term mean vs. 40% of summer redistributed to fall and spring with same annual total). Warming treatments (ambient vs. 24-hr IR canopy warming of 1-3°C) were applied to planted monocultures of juniper and little bluestem, and a juniper-grass combination. Both juniper and little bluestem are key species within the post oak savanna region. Plots were sampled from the full factorial design during years six and seven of the WaRM experiment. Soil N-mineralization, nitrification, and N-losses via leaching were assessed quarterly for two years using the resin core incubation method. Rainfall, species composition, and time interacted significantly to influence both ammonification and nitrification. Highest rates of ammonification (0.115 mg NH4+ -N/ kg soil/day) occurred in grass monocultures during summer in the control rainfall plots, whereas highest rates of nitrification (1.581 mg NO2-/NO3- -N/ kg soil/day) were in juniper monocultures during fall and spring in redistributed rainfall treatments. Lowest rates of ammonification (0.002 mg NH4+ -N/ kg soil/day) occurred under grass during fall and winter in redistributed rainfall plots, while lowest rates of nitrification (-0.016 mg NO2-/NO3- -N/ kg soil/day) were in juniper-grass mixtures during fall and winter in redistributed rainfall plots. Losses of N through leaching were highest in the same treatment combinations that had high rates of nitrification. Results indicate that while rainfall redistribution interacted strongly with other experimental treatments to influence rates of N-transformations, warming had little effect. These changes in rates of N-transformations and leaching losses in response to global change drivers may have important implications for net primary production, soil fertility, carbon storage, trace gas fluxes, water quality, interspecific interactions, and vegetation dynamics in the oak savanna region of North America.

Shallow Groundwater Discharge into Urban Drains: Identifying the Missing Link to Define Urban Typologies for Impact Assessment of Urbanization on Water and Nutrient Balances

NASA Astrophysics Data System (ADS)

Ocampo, C. J.; Oldham, C. E.

2015-12-01

Groundwater and surface water (GW-SW) interaction in drains of many sandy coastal plain areas displays an ephemeral hydrological regime, as often shifts occur in their hydraulic functioning from a losing to a gaining water conditions upon the position of the surrounding shallow water table (SWT). Urbanization in such areas and stormwater management strategies enhancing infiltration have the potential to alter the infiltration rates and the subsurface water storage dynamics with consequences for the residence time of the water and nutrient transformations prior their discharge into receiving SW drains. Identifying first order control on the above processes will assist the improvement of assessment tools for better urban development. This work presents findings on the hydrodynamics of the GW-SW water exchange in two drains of the Perth Coastal Plain area (Western Australia, Australia) impacted by a SWT developing on a layered variable texture soil: a peri-urban drain and a restored living stream drain in urban residential area. A multi-technique approach was used to investigate water mass balance and fluxes over a reach scale and involved continuous records of hydrometric data for GW-SW interactions, passive tracers for water pathway identification, pore water temperature for vertical water exchange, and differential SW discharge using an Acoustic Doppler Current Profiler. Results highlighted differences in the GW-SW interactions between both drains under stormflow and baseflow conditions. A substantial increase of GW discharge into the drain coincided with the full development of a SWT over a seasonal scale at the peri-urban drain, which suggests a more natural water infiltration and redistribution in the subsurface. In contrast, a large volume of infiltrated rain water was discharged into the living stream over a period of few weeks regardless of the development of the surrounding SWT, which suggests the influence of underground pipe system in water redistribution. The results contributed to identify key physical parameters to define urban typologies, quantify the subsurface storage discharge and residence time, and finally assess the transport and transformations of nutrients using a generalised Damköhler number. Future work will populate the framework with other study cases.

A Mathematical Model on Water Redistribution Mechanism of the Seismonastic Movement of Mimosa Pudica

PubMed Central

Kwan, K.W.; Ye, Z.W.; Chye, M.L.; Ngan, A.H.W.

2013-01-01

A theoretical model based on the water redistribution mechanism is proposed to predict the volumetric strain of motor cells in Mimosa pudica during the seismonastic movement. The model describes the water and ion movements following the opening of ion channels triggered by stimulation. The cellular strain is related to the angular velocity of the plant movement, and both their predictions are in good agreement with experimental data, thus validating the water redistribution mechanism. The results reveal that an increase in ion diffusivity across the cell membrane of <15-fold is sufficient to produce the observed seismonastic movement. PMID:23823246

Anthropogenic radionuclides for estimating rates of soil redistribution by wind

USDA-ARS?s Scientific Manuscript database

Erosion of soil by wind and water is a degrading process that affects millions of hectares worldwide. Atmospheric testing of nuclear weapons and the resulting fallout of anthropogenic radioisotopes, particularly Cesium 137, has made possible the estimation of mean soil redistribution rates. The pe...

Anthropogenic radioisotopes to estimate rates of soil redistribution by wind

USDA-ARS?s Scientific Manuscript database

Erosion of soil by wind and water is a degrading process that affects millions of hectares worldwide. Atmospheric testing of nuclear weapons and the resulting fallout of anthropogenic radioisotopes, particularly Cesium 137, has made possible the estimation of mean soil redistribution rates. The pe...

HYDRAULIC REDISTRIBUTION IN A DOUGLAS-FIR FOREST: LESSONS FROM SYSTEM MANIPULATIONS

EPA Science Inventory

Hydraulic redistribution (HR) has been shown to slow drying of surface soils during drought in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the...

HYDRAULIC REDISTRIBUTION IN A DOUGLAS-FIR FOREST: LESSONS FROM SYSTEM MANIPULATIONS

EPA Science Inventory

Hydraulic redistribution (HR) occurs in many ecosystems; however, key questions remain about its consequences at the ecosystem level. The objectives of the present study were to quantify seasonal variation in HR and its driving force, and to manipulate the soil-root system to e...

Modelling evolution of air dose rates in river basins in Fukushima Prefecture affected by sediment-sorbed radiocesium redistribution

NASA Astrophysics Data System (ADS)

Malins, A.; Sakuma, K.; Nakanishi, T.; Kurikami, H.; Machida, M.; Kitamura, A.; Yamada, S.

2015-12-01

The radioactive 134Cs and 137Cs isotopes deposited over Fukushima Prefecture by the Fukushima Daiichi nuclear disaster are the predominant radiological concern for the years following the accident. This is because the energetic gamma radiation they emit on decay constitutes the majority of the elevated air dose rates that now afflict the region. Therefore, we developed a tool for calculating air dose rates from arbitrary radiocesium spatial distributions across the land surface and depth profiles within the ground. As cesium is strongly absorbed by clay soils, its primary redistribution mechanism within Fukushima Prefecture is by soil erosion and water-borne sediment transport. Each year between 0.1~1% of the total radiocesium inventory in the river basins neighboring Fukushima Daiichi is eroded from the land surface and enters into water courses, predominantly during typhoon storms. Although this is a small amount in relative terms, in absolute terms it corresponds to terabecquerels of 134Cs and 137Cs redistribution each year and this can affect the air dose rate at locations of high erosion and sediment deposition. This study inputs the results of sediment redistribution simulations into the dose rate evaluation tool to calculate the locations and magnitude of air dose rate changes due to radiocesium redistribution. The dose rate calculations are supported by handheld survey instrument results taken within the Prefecture.

Rotational Dynamics and Time-variable Gravity of Mars and Implications for Volatile Cycling and Atmospheric Structure

NASA Technical Reports Server (NTRS)

Zuber, M. T.; Smith, D. E.

2002-01-01

The seasonal motion of atmospheric material, its deposition and sublimation at the poles, represent a minute redistribution of the planet's mass which has been detected in the motion of the Mars Global Surveyor (MGS) spacecraft. These observations have enabled us to estimate the quantity of material involved. Additional information is contained in the original extended abstract.

Externalization of phosphatidylserine via multidrug resistance 1 (MDR1)/P-glycoprotein in oxalate-treated renal epithelial cells: implications for calcium oxalate urolithiasis.

PubMed

Li, Yu-Hang; Yu, Shi-Liang; Gan, Xiu-Guo; Pan, Shang-Ha; Teng, Yue-Qiu; An, Rui-Hua

2016-02-01

We investigated the possible involvement of multidrug resistance protein 1 P-glycoprotein (MDR1 P-gp) in the oxalate-induced redistribution of phosphatidylserine in renal epithelial cell membranes. Real-time PCR and western blotting were used to examine MDR1 expression in Madin-Darby canine kidney cells at the mRNA and protein levels, respectively, whereas surface-expressed phosphatidylserine was detected by the annexin V-binding assay. Oxalate treatment resulted in increased synthesis of MDR1, which resulted in phosphatidylserine (PS) externalization in the renal epithelial cell membrane. Treatment with the MDR1 inhibitor PSC833 significantly attenuated phosphatidylserine externalization. Transfection of the human MDR1 gene into renal epithelial cells significantly increased PS externalization. To our knowledge, this study is the first to show that oxalate increases the synthesis of MDR1 P-gp, which plays a key role in hyperoxaluria-promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.

Magnetosphere-Ionosphere Energy Interchange in the Electron Diffuse Aurora

NASA Technical Reports Server (NTRS)

Khazanov, George V.; Glocer, Alex; Himwich, E. W.

2014-01-01

The diffuse aurora has recently been shown to be a major contributor of energy flux into the Earth's ionosphere. Therefore, a comprehensive theoretical analysis is required to understand its role in energy redistribution in the coupled ionosphere-magnetosphere system. In previous theoretical descriptions of precipitated magnetospheric electrons (E is approximately 1 keV), the major focus has been the ionization and excitation rates of the neutral atmosphere and the energy deposition rate to thermal ionospheric electrons. However, these precipitating electrons will also produce secondary electrons via impact ionization of the neutral atmosphere. This paper presents the solution of the Boltzman-Landau kinetic equation that uniformly describes the entire electron distribution function in the diffuse aurora, including the affiliated production of secondary electrons (E greater than 600 eV) and their ionosphere-magnetosphere coupling processes. In this article, we discuss for the first time how diffuse electron precipitation into the atmosphere and the associated secondary electron production participate in ionosphere-magnetosphere energy redistribution.

Geochemical consequences of flow differentiation in a multiple injection dike (Trinity ophiolite, N. California)

USGS Publications Warehouse

Brouxel, M.

1991-01-01

A clinopyroxene-rich dike of the Trinity ophiolite sheeted-dike complex shows three different magmatic pulses, probably injected in a short period of time (no well developed chilled margin) and important variations of the clinopyroxene and plagioclase percentages between its core (highly porphyritic) and margins (aphyric). This variation, interpreted as related to a flow differentiation phenomenon (mechanical phenocryst redistribution), has important geochemical consequences. It produces increases in the FeO, MgO, CaO, Cr and Ni contents from the margin to the core, together with increases in the clinopyroxene percentage, and decreases in the SiO2, Zr, Y, Nb and REE contents together with a decrease in the percentage of the fine-grained groundmass toward the core of the dike. This mineralogical redistribution, which also affects the incompatible trace element ratios because of the difference in plagioclase and clinopyroxene mineral/liquid partition coefficients, illustrate the importance of fractionation processes outside of a magma chamber. ?? 1991.

Sediment phosphorus speciation and mobility under dynamic redox conditions

NASA Astrophysics Data System (ADS)

Parsons, Chris T.; Rezanezhad, Fereidoun; O'Connell, David W.; Van Cappellen, Philippe

2017-07-01

Anthropogenic nutrient enrichment has caused phosphorus (P) accumulation in many freshwater sediments, raising concerns that internal loading from legacy P may delay the recovery of aquatic ecosystems suffering from eutrophication. Benthic recycling of P strongly depends on the redox regime within surficial sediment. In many shallow environments, redox conditions tend to be highly dynamic as a result of, among others, bioturbation by macrofauna, root activity, sediment resuspension and seasonal variations in bottom-water oxygen (O2) concentrations. To gain insight into the mobility and biogeochemistry of P under fluctuating redox conditions, a suspension of sediment from a hypereutrophic freshwater marsh was exposed to alternating 7-day periods of purging with air and nitrogen gas (N2), for a total duration of 74 days, in a bioreactor system. We present comprehensive data time series of bulk aqueous- and solid-phase chemistry, solid-phase phosphorus speciation and hydrolytic enzyme activities demonstrating the mass balanced redistribution of P in sediment during redox cycling. Aqueous phosphate concentrations remained low ( ˜ 2.5 µM) under oxic conditions due to sorption to iron(III) oxyhydroxides. During anoxic periods, once nitrate was depleted, the reductive dissolution of iron(III) oxyhydroxides released P. However, only 4.5 % of the released P accumulated in solution while the rest was redistributed between the MgCl2 and NaHCO3 extractable fractions of the solid phase. Thus, under the short redox fluctuations imposed in the experiments, P remobilization to the aqueous phase remained relatively limited. Orthophosphate predominated at all times during the experiment in both the solid and aqueous phase. Combined P monoesters and diesters accounted for between 9 and 16 % of sediment particulate P. Phosphatase activities up to 2.4 mmol h-1 kg-1 indicated the potential for rapid mineralization of organic P (Po), in particular during periods of aeration when the activity of phosphomonoesterases was 37 % higher than under N2 sparging. The results emphasize that the magnitude and timing of internal P loading during periods of anoxia are dependent on both P redistribution within sediments and bottom-water nitrate concentrations.

Carbon redistribution by erosion processes in an intensively disturbed catchment

NASA Astrophysics Data System (ADS)

Boix-Fayos, Carolina; Martínez-Mena, María; Pérez Cutillas, Pedro; de Vente, Joris; Barberá, Gonzalo G.; Mosch, Wouter; Navarro Cano, Jose Antonio; Gaspar, Leticia; Navas, Ana

2016-04-01

Understanding how organic carbon moves with sediments along the fluvial system is crucial to close catchment scale carbon budgets. Especially challenging is the analysis of organic carbon dynamics during fluvial transport in heterogeneous, fragile and disturbed environments with ephemeral and intense hydrological pulses, typical of Mediterranean conditions. This paper explores the catchment scale organic carbon redistribution by lateral flows in extreme Mediterranean environmental conditions from a geomorphological perspective. The study area is a catchment (Cárcavo) in SE Spain with a semiarid climate, erodible lithologies, shallow soils, and highly disturbed by agricultural terraces, land levelling, reforestations and construction of check-dams. To increase understanding of erosion induced catchment scale organic carbon redistribution, we studied the subcatchments of 8 check-dams distributed along the catchment main channel in detail. We determined 137Cs, physicochemical characteristics and organic carbon pools of soils and sediments deposited behind each check-dam, performed spatial analysis of properties of the catchment and buffer areas around check-dams, and carried out geomorphological analysis of the slope-channel connections. Soils showed very low Total Organic Carbon (TOC) values oscillating between 15.2 and 4.4 g Kg-1 for forest and agricultural soils, respectively. Sediments mobilized by erosion were poor in TOC compared to the eroded (forest) soils (6.6±0.7 g Kg-1), and the redistribution of organic carbon through the catchment, especially of the Mineral Associated Organic Carbon (MAC) pool, showed the same pattern as clay particles and 137Cs. The TOC erosion rates (0.031±0.03 Mg ha-1 y-1) were comparable to others reported for subhumid Mediterranean catchments and to those modelled worldwide for pasture land. Those lateral fluxes were equivalent to 10.4 % of the TOC stock from the topsoil at the moment of the check-dam construction and reforestation works. However the organic carbon in deposited sediments comes not only from surface erosion processes, but also from deeper soil or sediment layers mobilized by concentrated erosion processes. Sediment richer in organic carbon comes from the soil surface of vegetated (reforested) areas close and well connected to the channels. Subcatchments dominated by laminar erosion processes showed two times higher TOC/total erosion ratio than subcatchments dominated by concentrated flow erosion processes. Lithology, soils and geomorphology exert a more important control on organic carbon redistribution than land use and vegetation cover in this geomorphologically very active catchment.

Population Redistribution in the Midwest.

ERIC Educational Resources Information Center

Roseman, Curtis C., Ed.; And Others

The nine chapters in the book focus on the 1970s' metropolitan to nonmetropolitan migration stream and address both population patterns and processes and the impacts and policy issues associated with the resulting population redistribution in the Midwest. Peter A. Morrison places the Midwest in the national context of changing population structure…

HYDRAULIC REDISTRIBUTION OF SOIL WATER IN TWO OLD-GROWTH CONIFEROUS FORESTS: QUANTIFYING PATTERNS AND CONTROLS

EPA Science Inventory

Although hydraulic redistribution of soil water (HR) by roots is a widespread phenomenon, the processes governing spatial and temporal patterns of HR are not well understood. We incorporated soil/plant biophysical properties into a simple model based on Darcy's law to predict sea...

Impacts of hydraulic redistribution on grass-tree competition versus facilitation in a semiarid savanna

USDA-ARS?s Scientific Manuscript database

-A long-standing ambition in ecosystem science has been to understand the relationship between ecosystem community composition, structure and function. Differential water use and hydraulic redistribution have been proposed as one mechanism that might allow for the coexistence of overstory woody plan...

Differences in Preferential Sorting of Fine Particles in the Panama Basin Over the Past 25 kyr: Effects on 230Th-derived Focusing Factors

NASA Astrophysics Data System (ADS)

Loveley, M. R.; Marcantonio, F.; Lyle, M. W.; Wang, J. K.

2013-12-01

In this study, we attempt to understand how preferential sorting of fine particles during redistribution processes in the Panama Basin affects the 230Th constant-flux proxy. Fine particles likely contain greater amounts of 230Th, so that preferential sorting of fine particles may bias sediment mass accumulation rates (MARs). We examined sediments that span the past 25 kyr from two new sediment cores retrieved within about 56 km of each other in the northern part of the basin (MV1013-01-'4JC', 5° 44.699'N 85° 45.498' W, 1730 m depth; MV1014-01-'8JC', 6° 14.038'N 86° 2.613' W, 1993 m depth). Core 4JC, closer to the ridge top that bounds the basin (Cocos Ridge), has a thin sediment drape, while the deeper core 8JC, has a thicker sediment drape and lies further from the ridge top. 230Th-derived focusing factors from 4JC are similar and suggest winnowing with average values of about 0.5 and 0.6 during the Holocene and the last glacial, respectively. For 8JC, calculated average focusing factors are significantly different and suggest focusing with values of about 2 during the Holocene and 4 during the last glacial. Since the two sites are close to each other, one would expect similar rain rates and, therefore, similar 230Th-derived MARs within similar windows of time, i.e., the rain rate should not vary significantly at each site temporally. In addition, the radiocarbon-derived sand (>63μm) MARs should behave similarly since coarser particles are likely not transported by bottom currents. Sand MARs are, indeed, similar during the Holocene and the last glacial at each site. During the last glacial, however, sand MARs are about a factor of 3 higher than those during the Holocene. On the other hand, there is little variability in the 230Th-derived MARs both spatially and temporally. We interpret the discrepancies between the radiocarbon-derived sand and 230Th-derived MARs as being due to preferential sorting of fine particles during the redistribution of sediments by deep-sea currents. The 230Th-derived focusing factors are being overestimated at the deeper site and vice versa at the shallower site, and the degree of inaccuracy varies temporally. We discuss this temporal variability and its relationship to deep-sea current velocities.

Linking runoff and erosion dynamics to nutrient fluxes in a degrading dryland landscape

NASA Astrophysics Data System (ADS)

Michaelides, Katerina; Lister, Debbie; Wainwright, John; Parsons, Anthony J.

2012-12-01

Current theories of land degradation assume that shifts in vegetation communities result in changes to the rates and patterns of water and sediment movement, which are vectors of nutrient redistribution. This nutrient redistribution is hypothesized to reinforce, through positive feedbacks, progressive vegetation changes toward a more degraded ecosystem. A key component of this theory, which is currently poorly resolved, is the relative role of runoff and erosion in driving nutrient fluxes from different vegetation types. We address this gap through a series of field-based, rainfall-simulation experiments designed to explore plant-level dynamics of runoff- and erosion-driven nutrient fluxes of N, P and K species. Our results highlight important linkages between physical and biogeochemical processes that are controlled by plant structure. We found that: 1) the magnitude of sediment-bound nutrient export is determined by the grain-size distribution of the eroded sediment and the total sediment yield; 2) the partitioning of nutrients in dissolved and sediment-bound form is determined by the availability and concentration of different nutrient species in the soil or rainfall; 3) these processes varied according to vegetation type and resulted in stark differences between degrading and invading plant communities. Specifically, we observed that grassland areas consistently exported the highest yields of sediment-bound N, P and K despite producing similar erosion rates to shrub and intershrub areas. Our results have implications for better understanding how grassland areas are being replaced by shrubs and provide insights into the mechanisms of continuing land degradation in drylands.

Simulating Complex, Cold-region Process Interactions Using a Multi-scale, Variable-complexity Hydrological Model

NASA Astrophysics Data System (ADS)

Marsh, C.; Pomeroy, J. W.; Wheater, H. S.

2017-12-01

Accurate management of water resources is necessary for social, economic, and environmental sustainability worldwide. In locations with seasonal snowcovers, the accurate prediction of these water resources is further complicated due to frozen soils, solid-phase precipitation, blowing snow transport, and snowcover-vegetation-atmosphere interactions. Complex process interactions and feedbacks are a key feature of hydrological systems and may result in emergent phenomena, i.e., the arising of novel and unexpected properties within a complex system. One example is the feedback associated with blowing snow redistribution, which can lead to drifts that cause locally-increased soil moisture, thus increasing plant growth that in turn subsequently impacts snow redistribution, creating larger drifts. Attempting to simulate these emergent behaviours is a significant challenge, however, and there is concern that process conceptualizations within current models are too incomplete to represent the needed interactions. An improved understanding of the role of emergence in hydrological systems often requires high resolution distributed numerical hydrological models that incorporate the relevant process dynamics. The Canadian Hydrological Model (CHM) provides a novel tool for examining cold region hydrological systems. Key features include efficient terrain representation, allowing simulations at various spatial scales, reduced computational overhead, and a modular process representation allowing for an alternative-hypothesis framework. Using both physics-based and conceptual process representations sourced from long term process studies and the current cold regions literature allows for comparison of process representations and importantly, their ability to produce emergent behaviours. Examining the system in a holistic, process-based manner can hopefully derive important insights and aid in development of improved process representations.

Solar-terrestrial coupling through atmospheric electricity

NASA Technical Reports Server (NTRS)

Roble, R. G.; Hays, P. B.

1979-01-01

There are a number of measurements of electrical variations that suggest a solar-terrestrial influence on the global atmospheric electrical circuit. The measurements show variations associated with solar flares, solar magnetic sector boundary crossings, geomagnetic activity, aurorae, differences between ground current and potential gradients at high and low latitudes, and solar cycle variations. The evidence for each variation is examined. Both the experimental evidence and the calculations made with a global model of atmospheric electricity indicate that there is solar-terrestrial coupling through atmospheric electricity which operates by altering the global electric current and field distribution. A global redistribution of currents and fields can be caused by large-scale changes in electrical conductivity, by alteration of the columnar resistance between thunderstorm cloud tops and the ionosphere, or by both. If the columnar resistance is altered above thunderstorms, more current will flow in the global circuit, changing the ionospheric potential and basic circuit variables such as current density and electric fields. The observed variations of currents and fields during solar-induced disturbances are generally less than 50% of mean values near the earth's surface.

Testing GIC Mitigation Protocols by Modelling Transformer-Level GIC Flow in New Zealand's Electrical Transmission Grid

NASA Astrophysics Data System (ADS)

Divett, T.; Ingham, M.; Rodger, C. J.; Richardson, G. S.; Beggan, C.; Thomson, A. W. P.; Dalzell, M.; Mac Manus, D. H.

2017-12-01

Transformers in the South Island of Transpower New Zealand Ltd's electrical transmission network have been impacted by geomagnetically induced currents (GIC) during geomagnetic storms, including the November 2001 event. We aim to make recommendations that lead to improving mitigation strategies for reducing these impacts during extreme events. We have adapted a thin-sheet electromagnetic and GIC network modelling approach that has previously been successfully used in the UK to New Zealand's geology and transmission network. In this presentation we show how we have used this approach to explore Transpower's mitigation procedure as well as alternative mitigation options for reducing the impact of space weather on the network. In order to compare modelled GIC with what has been described as `possibly the best GIC dataset in the world' (Boteler and Pirjola, Pers. Comm. 2016) our model includes every transformer and every high voltage transmission line in the South Island network. This level of detail was required to match the transformer level observations of GIC in the network and to appropriately assess the mitigation options at the level where the damage to power networks occurs. We found that removing a single generator at a central power station and four transmission lines is enough to effectively redistribute GIC away from transformers that have previously experienced very high GIC (as shown in Figure). The redistributed GIC is less damaging to the transformers that it is redistributed to due to lower total GIC at those locations. In the past the impact of GIC on transformers has occurred in the first two minutes of a storm. Hence, mitigation strategies that currently rely on human intervention and involving delays of up to 15 minutes may need to be initiated very rapidly, in a significant departure from Transpower's existing protocol. Reducing delays should significantly reduce the potential for damage in a storm equivalent to the 2001 event. During an extreme storm we expect GIC of 300 A or more to flow through multiple transformers across both islands. In the case of an extreme storm we suggest the more drastic approach of floating the entire network to reduce the potential for damage while retaining power supply to the majority of the country.

Oceanic signals in rapid polar motion: results from a barotropic forward model with explicit consideration of self-attraction and loading effects

NASA Astrophysics Data System (ADS)

Schindelegger, Michael; Quinn, Katherine J.; Ponte, Rui M.

2017-04-01

Numerical modeling of non-tidal variations in ocean currents and bottom pressure has played a key role in closing the excitation budget of Earth's polar motion for a wide range of periodicities. Non-negligible discrepancies between observations and model accounts of pole position changes prevail, however, on sub-monthly time scales and call for examination of hydrodynamic effects usually omitted in general circulation models. Specifically, complete hydrodynamic cores must incorporate self-attraction and loading (SAL) feedbacks on redistributed water masses, effects that produces ocean bottom pressure perturbations of typically about 10% relative to the computed mass variations. Here, we report on a benchmark simulation with a near-global, barotropic forward model forced by wind stress, atmospheric pressure, and a properly calculated SAL term. The latter is obtained by decomposing ocean mass anomalies on a 30-minute grid into spherical harmonics at each time step and applying Love numbers to account for seafloor deformation and changed gravitational attraction. The increase in computational time at each time step is on the order of 50%. Preliminary results indicate that the explicit consideration of SAL in the forward runs increases the fidelity of modeled polar motion excitations, in particular on time scales shorter than 5 days as evident from cross spectral comparisons with geodetic excitation. Definite conclusions regarding the relevance of SAL in simulating rapid polar motion are, however, still hampered by the model's incomplete domain representation that excludes parts of the highly energetic Arctic Ocean.

A two-dimensional, time-dependent model of suspended sediment transport and bed reworking for continental shelves

USGS Publications Warehouse

Harris, C.K.; Wiberg, P.L.

2001-01-01

A two-dimensional, time-dependent solution to the transport equation is formulated to account for advection and diffusion of sediment suspended in the bottom boundary layer of continental shelves. This model utilizes a semi-implicit, upwind-differencing scheme to solve the advection-diffusion equation across a two-dimensional transect that is configured so that one dimension is the vertical, and the other is a horizontal dimension usually aligned perpendicular to shelf bathymetry. The model calculates suspended sediment concentration and flux; and requires as input wave properties, current velocities, sediment size distributions, and hydrodynamic sediment properties. From the calculated two-dimensional suspended sediment fluxes, we quantify the redistribution of shelf sediment, bed erosion, and deposition for several sediment sizes during resuspension events. The two-dimensional, time-dependent approach directly accounts for cross-shelf gradients in bed shear stress and sediment properties, as well as transport that occurs before steady-state suspended sediment concentrations have been attained. By including the vertical dimension in the calculations, we avoid depth-averaging suspended sediment concentrations and fluxes, and directly account for differences in transport rates and directions for fine and coarse sediment in the bottom boundary layer. A flux condition is used as the bottom boundary condition for the transport equation in order to capture time-dependence of the suspended sediment field. Model calculations demonstrate the significance of both time-dependent and spatial terms on transport and depositional patterns on continental shelves. ?? 2001 Elsevier Science Ltd. All rights reserved.

Is Biology Destiny? Birth Weight and Differential Parental Treatment

PubMed Central

Hsin, Amy

2016-01-01

Time diaries of sibling pairs from the PSID-CDS are used to determine whether maternal time investments compensate for or reinforce birth-weight differences among children. The findings demonstrate that the direction and degree of differential treatment vary by mother's education. Less-educated mothers devote more total time and more educationally oriented time to heavier-birth-weight children, whereas better-educated mothers devote more total and more educationally oriented time to lower-birth-weight children. The compensating effects observed among highly educated mothers are substantially larger than the reinforcing effects among the least-educated mothers. The findings show that families redistribute resources in ways that both compensate for and exacerbate early-life disadvantages. PMID:22865101

A mathematical model on water redistribution mechanism of the seismonastic movement of Mimosa pudica.

PubMed

Kwan, K W; Ye, Z W; Chye, M L; Ngan, A H W

2013-07-02

A theoretical model based on the water redistribution mechanism is proposed to predict the volumetric strain of motor cells in Mimosa pudica during the seismonastic movement. The model describes the water and ion movements following the opening of ion channels triggered by stimulation. The cellular strain is related to the angular velocity of the plant movement, and both their predictions are in good agreement with experimental data, thus validating the water redistribution mechanism. The results reveal that an increase in ion diffusivity across the cell membrane of <15-fold is sufficient to produce the observed seismonastic movement. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Empirical comparison of heuristic load distribution in point-to-point multicomputer networks

NASA Technical Reports Server (NTRS)

Grunwald, Dirk C.; Nazief, Bobby A. A.; Reed, Daniel A.

1990-01-01

The study compared several load placement algorithms using instrumented programs and synthetic program models. Salient characteristics of these program traces (total computation time, total number of messages sent, and average message time) span two orders of magnitude. Load distribution algorithms determine the initial placement for processes, a precursor to the more general problem of load redistribution. It is found that desirable workload distribution strategies will place new processes globally, rather than locally, to spread processes rapidly, but that local information should be used to refine global placement.

Three-dimensional eddy current solution of a polyphase machine test model (abstract)

NASA Astrophysics Data System (ADS)

Pahner, Uwe; Belmans, Ronnie; Ostovic, Vlado

1994-05-01

This abstract describes a three-dimensional (3D) finite element solution of a test model that has been reported in the literature. The model is a basis for calculating the current redistribution effects in the end windings of turbogenerators. The aim of the study is to see whether the analytical results of the test model can be found using a general purpose finite element package, thus indicating that the finite element model is accurate enough to treat real end winding problems. The real end winding problems cannot be solved analytically, as the geometry is far too complicated. The model consists of a polyphase coil set, containing 44 individual coils. This set generates a two pole mmf distribution on a cylindrical surface. The rotating field causes eddy currents to flow in the inner massive and conducting rotor. In the analytical solution a perfect sinusoidal mmf distribution is put forward. The finite element model contains 85824 tetrahedra and 16451 nodes. A complex single scalar potential representation is used in the nonconducting parts. The computation time required was 3 h and 42 min. The flux plots show that the field distribution is acceptable. Furthermore, the induced currents are calculated and compared with the values found from the analytical solution. The distribution of the eddy currents is very close to the distribution of the analytical solution. The most important results are the losses, both local and global. The value of the overall losses is less than 2% away from those of the analytical solution. Also the local distribution of the losses is at any given point less than 7% away from the analytical solution. The deviations of the results are acceptable and are partially due to the fact that the sinusoidal mmf distribution was not modeled perfectly in the finite element method.

Cesium 137-Its applications for understanding soil redistribution and deposition patterns on the landscape

USDA-ARS?s Scientific Manuscript database

In the 1960s research began on the application of fallout radionuclides to determine sediment deposition and soil redistribution rates and patterns in agricultural and natural ecosystems. This research was based on the use of fallout 137Cesium (137Cs) from nuclear weapon tests deposited worldwide d...

Correlation of interplanetary-space B sub z field fluctuations and trapped-particle redistribution.

NASA Technical Reports Server (NTRS)

Parks, G. K.; Pellat, R.

1972-01-01

Observations of interplanetary magnetic field fluctuations in correlation with trapped particle fluctuations are discussed. From observations of particle-redistribution effects, properties of the magnetospheric electric field are derived. The obtained results suggest that the interplanetary B(sub z) field fluctuations might represent a strong driving source for particle diffusion.

Everyone Is on Welfare: "The Role of Redistribution in Social Policy" Revisited.

ERIC Educational Resources Information Center

Abramovitz, Mimi

1983-01-01

Uses Titmuss's model of three welfare systems to analyze how the rapidly expanding system of tax benefits available to middle- and upper-income groups parallels the social welfare system for the poor. Operating as a shadow welfare state, the tax benefits system contributes to the upward redistribution of income. (Author/JAC)

The role of pre-event canopy storage in throughfall and stemflow by using isotopic tracers

Treesearch

S.T. Allen; J.R. Brooks; R.F. Keim; B.J. Bond; J.J. McDonnell

2014-01-01

Stable isotopes can be a valuable tool for tracing the redistribution, storage, and evaporation of water associated with canopy interception of rainfall. Isotopic differences between throughfall and rainfall have been attributed to three mechanisms: evaporative fractionation, isotopic exchange with ambient vapor, and temporal redistribution. We demonstrate the...

45 CFR 98.64 - Reallotment and redistribution of funds.

Code of Federal Regulations, 2014 CFR

2014-10-01

... will be based on the State's financial report to ACF for the Child Care and Development Fund (ACF-696... Section 98.64 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Financial Management § 98.64 Reallotment and redistribution of funds. (a) According to the...

45 CFR 98.64 - Reallotment and redistribution of funds.

Code of Federal Regulations, 2011 CFR

2011-10-01

... will be based on the State's financial report to ACF for the Child Care and Development Fund (ACF-696... Section 98.64 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Financial Management § 98.64 Reallotment and redistribution of funds. (a) According to the...

INTRODUCTING A THERMAL DISSIPATION PROBE SYSTEM FOR MEASURING BI-DIRECTIONAL ROOT WATER FLUX

EPA Science Inventory

The interest in measuring the direction and magnitude of root sapflow has accelerated in the past few years because of interest in the redistribution of water in the soil by roots. Plant roots have been shown to redistribute water between areas of soil with differing water conte...

Educational Policy and the Drug Problem--A Redistributive Politics Issue

ERIC Educational Resources Information Center

Caliguri, Joseph P.

1975-01-01

The drug problem exists as a cluster of problems affecting broad interests or groups. The issues are redistributive in that everything relates to everything else. It seems apparent that a cluster of policies and programs need development as well as genuine citizen participation in the formulation of these policies. (Author)

CONVERGING PATTERNS OF UPTAKE AND HYDRAULIC REDISTRIBUTION OF SOIL WATER IN CONTRASTING WOODY VEGETATION TYPES

EPA Science Inventory

We used concurrent measurements of soil water content and soil water potential (Ysoil) to assess the effects of Ysoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles in six sites characterized by different types and amounts of woo...

Hydraulic redistribution by two semi-arid shrub species: implications for Sahelian agro-ecosystems

Treesearch

F. Kizito; M.I. Dragila; M. Sene; J.R. Brooks; F.C. Meinzer; I. Diedhiou; M. Diouf; A. Lufafa; R.P. Dick; J. Selker; R. Cuenca

2012-01-01

Hydraulic redistribution is the process of passive water movement from deeper moist soil to shallower dry soil layers using plant roots as conduits. Results from this study indicate that this phenomenon exists among two shrub species (Guiera senegalensis and Piliostigma reticulatum) that co-exist with annual food crops in...

Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia

NASA Astrophysics Data System (ADS)

Buendía, Corina; Kleidon, Axel; Manzoni, Stefano; Reu, Björn; Porporato, Amilcare

2018-01-01

Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.

Effect of elastic strain redistribution on electronic band structures of compressively strained GaInAsP/InP membrane quantum wires

NASA Astrophysics Data System (ADS)

Ferdous, F.; Haque, A.

2007-05-01

The effect of redistribution of elastic strain relaxation on the energy band structures of GaInAsP/InP compressively strained membrane quantum wires fabricated by electron-beam lithography, reactive-ion etching and two-step epitaxial growth is theoretically studied using an 8-band k ṡp method. Anisotropic strain analysis by the finite element method shows that due to etching away the top and the bottom InP clad layers in membrane structures, redistribution of strain occurs. It is found that strain redistribution increases the effective bandgap of membrane quantum wire structures causing a blueshift of the emission frequency. Comparison with effective bandgap calculations neglecting confinement and band mixing demonstrates that neglect of these effects leads to an overestimation of the change in the bandgap. We have also investigated the effect of variation of wire width, barrier strain compensation, number of stacked quantum wire layers, and thickness of the top and the bottom residual InP layers in membrane structures on the change in the effective bandgap of membrane structures.

Food waste reduction practices in German food retail.

PubMed

Hermsdorf, David; Rombach, Meike; Bitsch, Vera

2017-01-01

The purpose of this paper is to investigate food retailers food waste reduction practices in Germany. The focus is on selling and redistributing agricultural produce with visual impairments and other surplus food items. In addition, drivers and barriers regarding the implementation of both waste reduction practices are explored. In total, 12 in-depth interviews with managerial actors in the food retail sector and a food bank spokesperson were recorded, transcribed and analyzed through a qualitative content analysis. In contrast to organic retailers, conventional retailers were reluctant to include agricultural produce with visual impairments in their product assortments, due to fears of negative consumer reactions. Another obstacle was EU marketing standards for specific produce. All retailers interviewed engaged in redistribution of surplus food. Logistics and the regulatory framework were the main barriers to food redistribution. The present study adds to the existing body of literature on food waste reduction practices as it explores selling produce with visual impairments and elaborates on the legal background of food redistribution in German retail. The results are the foundation for providing recommendations to policy makers and charitable food organizations.

Inequality and redistribution behavior in a give-or-take game

PubMed Central

Bechtel, Michael M.; Scheve, Kenneth F.

2018-01-01

Political polarization and extremism are widely thought to be driven by the surge in economic inequality in many countries around the world. Understanding why inequality persists depends on knowing the causal effect of inequality on individual behavior. We study how inequality affects redistribution behavior in a randomized “give-or-take” experiment that created equality, advantageous inequality, or disadvantageous inequality between two individuals before offering one of them the opportunity to either take from or give to the other. We estimate the causal effect of inequality in representative samples of German and American citizens (n = 4,966) and establish two main findings. First, individuals imperfectly equalize payoffs: On average, respondents transfer 12% of the available endowments to realize more equal wealth distributions. This means that respondents tolerate a considerable degree of inequality even in a setting in which there are no costs to redistribution. Second, redistribution behavior in response to disadvantageous and advantageous inequality is largely asymmetric: Individuals who take from those who are richer do not also tend to give to those who are poorer, and individuals who give to those who are poorer do not tend to take from those who are richer. These behavioral redistribution types correlate in meaningful ways with support for heavy taxes on the rich and the provision of welfare benefits for the poor. Consequently, it seems difficult to construct a majority coalition willing to back the type of government interventions needed to counter rising inequality. PMID:29555734

Cell-size distribution in epithelial tissue formation and homeostasis

PubMed Central

Primo, Luca; Celani, Antonio

2017-01-01

How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. PMID:28330988

Cell-size distribution in epithelial tissue formation and homeostasis.

PubMed

Puliafito, Alberto; Primo, Luca; Celani, Antonio

2017-03-01

How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. © 2017 The Author(s).

Visualising landscape evolution: the effects of resolution on soil redistribution

NASA Astrophysics Data System (ADS)

Schoorl, Jeroen M.; Claessens, Lieven; (A) Veldkamp, Tom

2017-04-01

Landscape forming processes such as erosion by water, land sliding by water and gravity or ploughing by gravity, are closely related to resolution and land use changes. These processes may be controlled and influenced by multiple bio-physical and socio-economic driving factors, resulting in a complex multi-scale system. Consequently, land use changes should not be analysed in isolation without accounting for both on-site and off-site effects of these landscape processes in landscapes where water driven and or gravity driven processes are very active,. Especially the visualisation of these on- and off-site effects as a movie of evolving time series and changes is a potential valuable possibility in DEM modelling approaches. To investigate the interactions between land use, land use change, resolution of DEMs and landscape processes, a case study for the Álora region in southern Spain will presented, mainly as movies of modelling time-series, Starting from a baseline scenario of land use change, different levels of resolutions, interactions and feedbacks are added to the coupled LAPSUS model framework: Quantities and spatial patterns of both land use change and soil redistribution are compared between the baseline scenario without interactions and with each of the interaction mechanisms implemented consecutively. All as a function of spatial resolution. Keywords: LAPSUS; land use change; soil erosion, movie;

A low-angle detachment fault revealed: Three-dimensional images of the S-reflector fault zone along the Galicia passive margin

NASA Astrophysics Data System (ADS)

Schuba, C. Nur; Gray, Gary G.; Morgan, Julia K.; Sawyer, Dale S.; Shillington, Donna J.; Reston, Tim J.; Bull, Jonathan M.; Jordan, Brian E.

2018-06-01

A new 3-D seismic reflection volume over the Galicia margin continent-ocean transition zone provides an unprecedented view of the prominent S-reflector detachment fault that underlies the outer part of the margin. This volume images the fault's structure from breakaway to termination. The filtered time-structure map of the S-reflector shows coherent corrugations parallel to the expected paleo-extension directions with an average azimuth of 107°. These corrugations maintain their orientations, wavelengths and amplitudes where overlying faults sole into the S-reflector, suggesting that the parts of the detachment fault containing multiple crustal blocks may have slipped as discrete units during its late stages. Another interface above the S-reflector, here named S‧, is identified and interpreted as the upper boundary of the fault zone associated with the detachment fault. This layer, named the S-interval, thickens by tens of meters from SE to NW in the direction of transport. Localized thick accumulations also occur near overlying fault intersections, suggesting either non-uniform fault rock production, or redistribution of fault rock during slip. These observations have important implications for understanding how detachment faults form and evolve over time. 3-D seismic reflection imaging has enabled unique insights into fault slip history, fault rock production and redistribution.

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

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

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

NASA Astrophysics Data System (ADS)

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

2017-04-01

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

Windowed and Wavelet Analysis of Marine Stratocumulus Cloud Inhomogeneity

NASA Technical Reports Server (NTRS)

Gollmer, Steven M.; Harshvardhan; Cahalan, Robert F.; Snider, Jack B.

1995-01-01

To improve radiative transfer calculations for inhomogeneous clouds, a consistent means of modeling inhomogeneity is needed. One current method of modeling cloud inhomogeneity is through the use of fractal parameters. This method is based on the supposition that cloud inhomogeneity over a large range of scales is related. An analysis technique named wavelet analysis provides a means of studying the multiscale nature of cloud inhomogeneity. In this paper, the authors discuss the analysis and modeling of cloud inhomogeneity through the use of wavelet analysis. Wavelet analysis as well as other windowed analysis techniques are used to study liquid water path (LWP) measurements obtained during the marine stratocumulus phase of the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment. Statistics obtained using analysis windows, which are translated to span the LWP dataset, are used to study the local (small scale) properties of the cloud field as well as their time dependence. The LWP data are transformed onto an orthogonal wavelet basis that represents the data as a number of times series. Each of these time series lies within a frequency band and has a mean frequency that is half the frequency of the previous band. Wavelet analysis combined with translated analysis windows reveals that the local standard deviation of each frequency band is correlated with the local standard deviation of the other frequency bands. The ratio between the standard deviation of adjacent frequency bands is 0.9 and remains constant with respect to time. This ratio defined as the variance coupling parameter is applicable to all of the frequency bands studied and appears to be related to the slope of the data's power spectrum. Similar analyses are performed on two cloud inhomogeneity models, which use fractal-based concepts to introduce inhomogeneity into a uniform cloud field. The bounded cascade model does this by iteratively redistributing LWP at each scale using the value of the local mean. This model is reformulated into a wavelet multiresolution framework, thereby presenting a number of variants of the bounded cascade model. One variant introduced in this paper is the 'variance coupled model,' which redistributes LWP using the local standard deviation and the variance coupling parameter. While the bounded cascade model provides an elegant two- parameter model for generating cloud inhomogeneity, the multiresolution framework provides more flexibility at the expense of model complexity. Comparisons are made with the results from the LWP data analysis to demonstrate both the strengths and weaknesses of these models.

Graphene-Nanodiamond Heterostructures and their application to High Current Devices

PubMed Central

Zhao, Fang; Vrajitoarea, Andrei; Jiang, Qi; Han, Xiaoyu; Chaudhary, Aysha; Welch, Joseph O.; Jackman, Richard B.

2015-01-01

Graphene on hydrogen terminated monolayer nanodiamond heterostructures provides a new way to improve carrier transport characteristics of the graphene, offering up to 60% improvement when compared with similar graphene on SiO2/Si substrates. These heterostructures offers excellent current-carrying abilities whilst offering the prospect of a fast, low cost and easy methodology for device applications. The use of ND monolayers is also a compatible technology for the support of large area graphene films. The nature of the C-H bonds between graphene and H-terminated NDs strongly influences the electronic character of the heterostructure, creating effective charge redistribution within the system. Field effect transistors (FETs) have been fabricated based on this novel herterostructure to demonstrate device characteristics and the potential of this approach. PMID:26350107

Multiyear fate of a 15 N tracer in a mixed deciduous forest: retention, redistribution, and differences by mycorrhizal association.

PubMed

Goodale, Christine L

2017-02-01

The impact of atmospheric nitrogen deposition on forest ecosystems depends in large part on its fate. Past tracer studies show that litter and soils dominate the short-term fate of added 15 N, yet few have examined its longer term dynamics or differences among forest types. This study examined the fate of a 15 N-NO3- tracer over 5-6 years in a mixed deciduous stand that was evenly composed of trees with ectomycorrhizal and arbuscular mycorrhizal associations. The tracer was expected to slowly mineralize from its main initial fate in litter and surface soil, with some 15 N moving to trees, some to deeper soil, and some net losses. Recovery of added 15 N in trees and litterfall totaled 11.3% both 1 and 5-6 years after the tracer addition, as 15 N redistributed from fine and especially coarse roots into cumulative litterfall and small accumulations in woody tissues. Estimates of potential carbon sequestration from tree 15 N recovery amounted to 12-14 kg C per kg of N deposition. Tree 15 N acquisition occurred within the first year after the tracer addition, with no subsequent additional net transfer of 15 N from detrital to plant pools. In both years, ectomycorrhizal trees gained 50% more of the tracer than did trees with arbuscular mycorrhizae. Much of the 15 N recovered in wood occurred in tree rings formed prior to the 15 N addition, demonstrating the mobility of N in wood. Tracer recovery rapidly decreased over time in surface litter material and accumulated in both shallow and deep soil, perhaps through mixing by earthworms. Overall, results showed redistribution of tracer 15 N through trees and surface soils without any losses, as whole-ecosystem recovery remained constant between 1 and 5-6 years at 70% of the 15 N addition. These results demonstrate the persistent ecosystem retention of N deposition even as it redistributes, without additional plant uptake over this timescale. © 2016 John Wiley & Sons Ltd.

Spitzer and z' secondary eclipse observations of the highly irradiated transiting brown dwarf KELT-1b

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

Beatty, Thomas G.; Gaudi, B. Scott; Collins, Karen A.

2014-03-10

We present secondary eclipse observations of the highly irradiated transiting brown dwarf KELT-1b. These observations represent the first constraints on the atmospheric dynamics of a highly irradiated brown dwarf, the atmospheres of irradiated giant planets at high surface gravity, and the atmospheres of brown dwarfs that are dominated by external, rather than internal, energy. Using the Spitzer Space Telescope, we measure secondary eclipse depths of 0.195% ± 0.010% at 3.6 μm and 0.200% ± 0.012% at 4.5 μm. We also find tentative evidence for the secondary eclipse in the z' band with a depth of 0.049% ± 0.023%. These measuredmore » eclipse depths are most consistent with an atmosphere model in which there is a strong substellar hotspot, implying that heat redistribution in the atmosphere of KELT-1b is low. While models with a more mild hotspot or even with dayside heat redistribution are only marginally disfavored, models with complete heat redistribution are strongly ruled out. The eclipse depths also prefer an atmosphere with no TiO inversion layer, although a model with TiO inversion is permitted in the dayside heat redistribution case, and we consider the possibility of a day-night TiO cold trap in this object. For the first time, we compare the IRAC colors of brown dwarfs and hot Jupiters as a function of effective temperature. Importantly, our measurements reveal that KELT-1b has a [3.6] – [4.5] color of 0.07 ± 0.11, identical to that of isolated brown dwarfs of similarly high temperature. In contrast, hot Jupiters generally show redder [3.6] – [4.5] colors of ∼0.4, with a very large range from ∼0 to ∼1. Evidently, despite being more similar to hot Jupiters than to isolated brown dwarfs in terms of external forcing of the atmosphere by stellar insolation, KELT-1b appears to have an atmosphere most like that of other brown dwarfs. This suggests that surface gravity is very important in controlling the atmospheric systems of substellar mass bodies.« less

Feedback Augmented Sub-Ranging (FASR) Quantizer

NASA Technical Reports Server (NTRS)

Guilligan, Gerard

2012-01-01

This innovation is intended to reduce the size, power, and complexity of pipeline analog-to-digital converters (ADCs) that require high resolution and speed along with low power. Digitizers are important components in any application where analog signals (such as light, sound, temperature, etc.) need to be digitally processed. The innovation implements amplification of a sampled residual voltage in a switched capacitor amplifier stage that does not depend on charge redistribution. The result is less sensitive to capacitor mismatches that cause gain errors, which are the main limitation of such amplifiers in pipeline ADCs. The residual errors due to mismatch are reduced by at least a factor of 16, which is equivalent to at least 4 bits of improvement. The settling time is also faster because of a higher feedback factor. In traditional switched capacitor residue amplifiers, closed-loop amplification of a sampled and held residue signal is achieved by redistributing sampled charge onto a feedback capacitor around a high-gain transconductance amplifier. The residual charge that was sampled during the acquisition or sampling phase is stored on two or more capacitors, often equal in value or integral multiples of each other. During the hold or amplification phase, all of the charge is redistributed onto one capacitor in the feedback loop of the amplifier to produce an amplified voltage. The key error source is the non-ideal ratios of feedback and input capacitors caused by manufacturing tolerances, called mismatches. The mismatches cause non-ideal closed-loop gain, leading to higher differential non-linearity. Traditional solutions to the mismatch errors are to use larger capacitor values (than dictated by thermal noise requirements) and/or complex calibration schemes, both of which increase the die size and power dissipation. The key features of this innovation are (1) the elimination of the need for charge redistribution to achieve an accurate closed-loop gain of two, (2) a higher feedback factor in the amplifier stage giving a higher closed-loop bandwidth compared to the prior art, and (3) reduced requirement for calibration. The accuracy of the new amplifier is mainly limited by the sampling networks parasitic capacitances, which should be minimized in relation to the sampling capacitors.

Roots bridge water to nutrients: a study of utilizing hydraulic redistribution through root systems to extract nutrients in the dry soils

NASA Astrophysics Data System (ADS)

Yan, J.; Ghezzehei, T. A.

2017-12-01

The rhizosphere is the region of soil that surrounds by individual plant roots. While its small volume and narrow region compared to bulk soil, the rhizosphere regulates numerous processes that determine physical structure, nutrient distribution, and biodiversity of soils. One of the most important and distinct functions of the rhizosphere is the capacity of roots to bridge and redistribute soil water from wet soil layers to drier layers. This process was identified and defined as hydraulic lift or hydraulic redistribution, a passive process driven by gradients in water potentials and it has attracted much research attention due to its important role in global water circulation and agriculture security. However, while previous studies mostly focused on the hydrological or physiological impacts of hydraulic redistribution, limited research has been conducted to elucidate its role in nutrient cycling and uptake. In this study, we aim to test the possibility of utilizing hydraulic redistribution to facilitate the nutrient movement and uptake from resource segregated zone. Our overarching hypothesis is that plants can extract nutrients from the drier but nutrient-rich regions by supplying sufficient amounts of water from the wet but nutrient-deficient regions. To test our hypothesis, we designed split-root systems of tomatoes with unequal supply of water and nutrients in different root compartments. More specifically, we transplanted tomato seedlings into sand or soil mediums, and grew them under conditions with alternate 12-h lightness and darkness. We continuously monitored the temperature, water and nutrient content of soils in these separated compartments. The above and below ground biomass were also quantified to evaluate the impacts on the plant growth. The results were compared to a control with evenly supply of water and nutrients to assess the plant growth, nutrient leaching and uptake without hydraulic redistribution.

Using plot experiments to test the validity of mass balance models employed to estimate soil redistribution rates from 137Cs and 210Pb(ex) measurements.

PubMed

Porto, Paolo; Walling, Des E

2012-10-01

Information on rates of soil loss from agricultural land is a key requirement for assessing both on-site soil degradation and potential off-site sediment problems. Many models and prediction procedures have been developed to estimate rates of soil loss and soil redistribution as a function of the local topography, hydrometeorology, soil type and land management, but empirical data remain essential for validating and calibrating such models and prediction procedures. Direct measurements using erosion plots are, however, costly and the results obtained relate to a small enclosed area, which may not be representative of the wider landscape. In recent years, the use of fallout radionuclides and more particularly caesium-137 ((137)Cs) and excess lead-210 ((210)Pb(ex)) has been shown to provide a very effective means of documenting rates of soil loss and soil and sediment redistribution in the landscape. Several of the assumptions associated with the theoretical conversion models used with such measurements remain essentially unvalidated. This contribution describes the results of a measurement programme involving five experimental plots located in southern Italy, aimed at validating several of the basic assumptions commonly associated with the use of mass balance models for estimating rates of soil redistribution on cultivated land from (137)Cs and (210)Pb(ex) measurements. Overall, the results confirm the general validity of these assumptions and the importance of taking account of the fate of fresh fallout. However, further work is required to validate the conversion models employed in using fallout radionuclide measurements to document soil redistribution in the landscape and this could usefully direct attention to different environments and to the validation of the final estimates of soil redistribution rate as well as the assumptions of the models employed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Selective uptake, distribution, and redistribution of (109)Cd, (57)Co, (65)Zn, (63)Ni, and (134)Cs via xylem and phloem in the heavy metal hyperaccumulator Solanum nigrum L.

PubMed

Wei, Shuhe; Anders, Iwona; Feller, Urs

2014-06-01

The focus of this article was to explore the translocation of (109)Cd, (57)Co, (65)Zn, (63)Ni, and (134)Cs via xylem and phloem in the newly found hyperaccumulator Solanum nigrum L. Two experiments with the uptake via the roots and transport of (109)Cd, (57)Co, and (65)Zn labeled by roots, and the redistribution of (109)Cd, (65)Zn, (57)Co, (63)Ni, and (134)Cs using flap label in S. nigrum in a hydroponic culture with a standard nutrient solution were conducted. The results showed that (109)Cd added for 24 h to the nutrient medium of young plants was rapidly taken up, transferred to the shoot, and accumulated in the cotyledons and the oldest leaves but was not efficiently redistributed within the shoot afterward leading to a rather low content in the fruits. In contrast, (57)Co was more slowly taken up and released to the shoot, but afterward, this element was redistributed from older leaves to younger leaves and maturing fruits. (65)Zn was rapidly taken up and transferred to the shoot (mainly to the youngest leaves and not to the cotyledons). Afterward, this radionuclide was redistributed within the shoot to the youngest organs and finally accumulated in the maturing fruits. After flap labeling, all five heavy metals tested ((109)Cd, (57)Co, (65)Zn, (63)Ni, (134)Cs) were exported from the labeled leaf and redistributed within the plant. The accumulation in the fruits was most pronounced for (63)Ni and (65)Zn, while a relatively high percentage of (57)Co was finally found in the roots. (134)Cs was roughly in the middle of them. The transport of (109)Cd differed from that previously reported for wheat or lupin and might be important for the potential of S. nigrum to hyperaccumulate cadmium.

Evaluation of a model framework to estimate soil and soil organic carbon redistribution by water and tillage using 137Cs in two U.S. Midwest agricultural fields

USGS Publications Warehouse

Young, Claudia J.; Liu, Shuguang; Schumacher, Joseph A.; Schumacher, Thomas E.; Kaspar, Thomas C.; McCarty, Gregory W.; Napton, Darrell; Jaynes, Dan B.

2014-01-01

Cultivated lands in the U.S. Midwest have been affected by soil erosion, causing soil organic carbon (SOC) redistribution in the landscape and other environmental and agricultural problems. The importance of SOC redistribution on soil productivity and crop yield, however, is still uncertain. In this study, we used a model framework, which includes the Unit Stream Power-based Erosion Deposition (USPED) and the Tillage Erosion Prediction (TEP) models, to understand the soil and SOC redistribution caused by water and tillage erosion in two agricultural fields in the U.S. Midwest. This model framework was evaluated for different digital elevation model (DEM) spatial resolutions (10-m, 24-m, 30-m, and 56-m) and topographic exponents (m = 1.0–1.6 and n = 1.0–1.3) using soil redistribution rates from 137Cs measurements. The results showed that the aggregated 24-m DEM, m = 1.4 and n = 1.0 for rill erosion, and m = 1.0 and n = 1.0 for sheet erosion, provided the best fit with the observation data at both sites. Moreover, estimated average SOC redistributions were 1.3 ± 9.8 g C m− 2 yr− 1 in field site 1 and 3.6 ± 14.3 g C m− 2 yr− 1 in field site 2. Spatial distribution patterns showed SOC loss (negative values) in the eroded areas and SOC gain (positive value) in the deposition areas. This study demonstrated the importance of the spatial resolution and the topographic exponents to estimate and map soil redistribution and the SOC dynamics throughout the landscape, helping to identify places where erosion and deposition from water and tillage are occurring at high rates. Additional research is needed to improve the application of the model framework for use in local and regional studies where rainfall erosivity and cover management factors vary. Therefore, using this model framework can help to improve the information about the spatial distribution of soil erosion across agricultural landscapes and to gain a better understanding of SOC dynamics within eroding and previously eroded fields.

Redistribution of phosphorus during Ni0.9Pt0.1-based silicide formation on phosphorus implanted Si substrates

NASA Astrophysics Data System (ADS)

Lemang, M.; Rodriguez, Ph.; Nemouchi, F.; Juhel, M.; Grégoire, M.; Mangelinck, D.

2018-02-01

Phosphorus diffusion and its distribution during the solid-state reactions between Ni0.9Pt0.1 and implanted Si substrates are studied. Silicidation is achieved through a first rapid thermal annealing followed by a selective etching and a direct surface annealing. The redistribution of phosphorus in silicide layers is investigated after the first annealing for different temperatures and after the second annealing. Phosphorus concentration profiles obtained thanks to time of flight secondary ion mass spectrometry and atom probe tomography characterizations for partial and total reactions of the deposited 7 nm thick Ni0.9Pt0.1 film are presented. Phosphorus segregation is observed at the Ni0.9Pt0.1 surface and at Ni2Si interfaces during Ni2Si formation and at the NiSi surface and the NiSi/Si interface after NiSi formation. The phosphorus is evidenced in low concentrations in the Ni2Si and NiSi layers. Once NiSi is formed, a bump in the phosphorus concentration is highlighted in the NiSi layer before the NiSi/Si interface. Based on these profiles, a model for the phosphorus redistribution is proposed to match this bump to the former Ni2Si/Si interface. It also aims to bind the phosphorus segregation and its low concentration in different silicides to a low solubility of phosphorus in Ni2Si and in NiSi and a fast diffusion of phosphorus at their grain boundaries. This model is also substantiated by a simulation using a finite difference method in one dimension.

Sediment redistribution and grainsize effects on 230Th-normalized mass accumulation rates and focusing factors in the Panama Basin

NASA Astrophysics Data System (ADS)

Loveley, Matthew R.; Marcantonio, Franco; Lyle, Mitchell; Ibrahim, Rami; Hertzberg, Jennifer E.; Schmidt, Matthew W.

2017-12-01

Here, we examine how redistribution of differing grain sizes by sediment focusing processes in Panama Basin sediments affects the use of 230Th as a constant-flux proxy. We study representative sediments of Holocene and Last Glacial Maximum (LGM) time slices from four sediment cores from two different localities close to the ridges that bound the Panama Basin. Each locality contains paired sites that are seismically interpreted to have undergone extremes in sediment redistribution, i.e., focused versus winnowed sites. Both Holocene and LGM samples from sites where winnowing has occurred contain significant amounts (up to 50%) of the 230Th within the >63 μm grain size fraction, which makes up 40-70% of the bulk sediment analyzed. For sites where focusing has occurred, Holocene and LGM samples contain the greatest amounts of 230Th (up to 49%) in the finest grain-sized fraction (<4 μm), which makes up 26-40% of the bulk sediment analyzed. There are slight underestimations of 230Th-derived mass accumulation rates (MARs) and overestimations of 230Th-derived focusing factors at focused sites, while the opposite is true for winnowed sites. Corrections made using a model by Kretschmer et al. (2010) suggest a maximum change of about 30% in 230Th-derived MARs and focusing factors at focused sites, except for our most focused site which requires an approximate 70% correction in one sample. Our 230Th-corrected 232Th flux results suggest that the boundary between hemipelagically- and pelagically-derived sediments falls between 350 and 600 km from the continental margin.

Countermeasures to microgravity

NASA Technical Reports Server (NTRS)

Luttges, Marvin W.

1989-01-01

Biological systems ranging from the most simple to the most complex generally survive exposure to microgravity. Changes in many characteristics of biological systems are well documented as a consequence of space flight. Attempts to devise countermeasures to microgravity may have direct pragmatic consequences for crew protection and may provide additional insights into the nature of microgravity influences on biological systems. Some of the most well documented changes occur in humans who have experienced space flight. Changes appear to be transient. Space adaption syndrome occurs relatively briefly whereas bone deterioration may require months of postflight time for restoration. It seems critical to recognize that these changes and others may derive from rather passive, active or even reactive changes in the biological systems that are hosts to them. For example, hydrostatic fluid redistributions may be quite passive occurrences that are realized through extensive fluid channels. Changes occur in cell metabolism because of fluid, nutrient and gas redistributions. Equally important are the misconstrued messages likely to be carried by fluid redistributions. These reactive events can trigger, for example, loss of fluids and electrolytes through altered kidney function. Each of these considerations must be evaluated in regard to the biological site affected. Countermeasures to the vast range of biological changes and sites are difficult to envision. The most obvious countermeasure is the restoration of gravity-like influences. Some options are discussed. Recent work has focussed on the use of magnetic fields. Pulsed electromagnetic fields (PEMF) are shown to alleviate bone deterioration produced in rodents exposed to tail suspension. Methods of PEMF exposure are consistent with human use in space. Related methods may provide muscular and neural benefits.

Substance P-induced trafficking of beta-arrestins. The role of beta-arrestins in endocytosis of the neurokinin-1 receptor.

PubMed

McConalogue, K; Déry, O; Lovett, M; Wong, H; Walsh, J H; Grady, E F; Bunnett, N W

1999-06-04

Agonist-induced redistribution of G-protein-coupled receptors (GPCRs) and beta-arrestins determines the subsequent cellular responsiveness to agonists and is important for signal transduction. We examined substance P (SP)-induced trafficking of beta-arrestin1 and the neurokinin-1 receptor (NK1R) in KNRK cells in real time using green fluorescent protein. Green fluorescent protein did not alter function or localization of the NK1R or beta-arrestin1. SP induced (a) striking and rapid (<1 min) translocation of beta-arrestin1 from the cytosol to the plasma membrane, which preceded NK1R endocytosis; (b) redistribution of the NK1R and beta-arrestin1 into the same endosomes containing SP and the transferrin receptor (2-10 min); (c) prolonged colocalization of the NK1R and beta-arrestin1 in endosomes (>60 min); (d) gradual resumption of the steady state distribution of the NK1R at the plasma membrane and beta-arrestin1 in the cytosol (4-6 h). SP stimulated a similar redistribution of immunoreactive beta-arrestin1 and beta-arrestin2. In contrast, SP did not affect Galphaq/11 distribution, which remained at the plasma membrane. Expression of the dominant negative beta-arrestin319-418 inhibited SP-induced endocytosis of the NK1R. Thus, SP induces rapid translocation of beta-arrestins to the plasma membrane, where they participate in NK1R endocytosis. beta-Arrestins colocalize with the NK1R in endosomes until the NK1R recycles and beta-arrestins return to the cytosol.

Potential influence of wildfire in modulating climate-induced forest redistribution in a central Rocky Mountain landscape

USGS Publications Warehouse

Campbell, John L.; Shinneman, Douglas

2017-01-01

IntroductionClimate change is expected to impose significant tension on the geographic distribution of tree species. Yet, tree species range shifts may be delayed by their long life spans, capacity to withstand long periods of physiological stress, and dispersal limitations. Wildfire could theoretically break this biological inertia by killing forest canopies and facilitating species redistribution under changing climate. We investigated the capacity of wildfire to modulate climate-induced tree redistribution across a montane landscape in the central Rocky Mountains under three climate scenarios (contemporary and two warmer future climates) and three wildfire scenarios (representing historical, suppressed, and future fire regimes).MethodsDistributions of four common tree species were projected over 90 years by pairing a climate niche model with a forest landscape simulation model that simulates species dispersal, establishment, and mortality under alternative disturbance regimes and climate scenarios.ResultsThree species (Douglas-fir, lodgepole pine, subalpine fir) declined in abundance over time, due to climate-driven contraction in area suitable for establishment, while one species (ponderosa pine) was unable to exploit climate-driven expansion of area suitable for establishment. Increased fire frequency accelerated declines in area occupied by Douglas-fir, lodgepole pine, and subalpine fir, and it maintained local abundance but not range expansion of ponderosa pine.ConclusionsWildfire may play a larger role in eliminating these conifer species along trailing edges of their distributions than facilitating establishment along leading edges, in part due to dispersal limitations and interspecific competition, and future populations may increasingly depend on persistence in locations unfavorable for their establishment.

Soil redistribution model for undisturbed and cultivated sites based on Chernobyl-derived cesium-137 fallout.

PubMed

Hrachowitz, Markus; Maringer, Franz-Josef; Steineder, Christian; Gerzabek, Martin H

2005-01-01

Measurements of 137Cs fallout have been used in combination with a range of conversion models for the investigation of soil relocation mechanisms and sediment budgets in many countries for more than 20 yr. The objective of this paper is to develop a conversion model for quantifying soil redistribution, based on Chernobyl-derived 137Cs. The model is applicable on uncultivated as well as on cultivated sites, taking into account temporal changes in the 137Cs depth distribution pattern as well as tillage-induced 137Cs dilution effects. The main idea of the new model is the combination of a modified exponential model describing uncultivated soil with a Chapman distribution based model describing cultivated soil. The compound model subsequently allows a dynamic description of the Chernobyl derived 137Cs situation in the soil and its change, specifically migration and soil transport processes over the course of time. Using the suggested model at the sampling site in Pettenbach, in the Austrian province of Oberösterreich 137Cs depth distributions were simulated with a correlation coefficient of 0.97 compared with the measured 137Cs depth profile. The simulated rates of soil distribution at different positions at the sampling site were found to be between 27 and 60 Mg ha(-1) yr(-1). It was shown that the model can be used to describe the temporal changes of 137Cs depth distributions in cultivated as well as uncultivated soils. Additionally, the model allows to quantify soil redistribution in good correspondence with already existing models.

Slow quench dynamics of a one-dimensional Bose gas confined to an optical lattice.

PubMed

Bernier, Jean-Sébastien; Roux, Guillaume; Kollath, Corinna

2011-05-20

We analyze the effect of a linear time variation of the interaction strength on a trapped one-dimensional Bose gas confined to an optical lattice. The evolution of different observables such as the experimentally accessible on site particle distribution are studied as a function of the ramp time by using time-dependent numerical techniques. We find that the dynamics of a trapped system typically displays two regimes: For long ramp times, the dynamics is governed by density redistribution, while at short ramp times, local dynamics dominates as the evolution is identical to that of an homogeneous system. In the homogeneous limit, we also discuss the nontrivial scaling of the energy absorbed with the ramp time.

Moment free toroidal magnet

DOEpatents

Bonanos, Peter

1983-01-01

A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.

Blood Pressure Responses and Mineral Ocorticoid Levels in the Suspended Rat Model for Weightlessness

NASA Technical Reports Server (NTRS)

Musacchia, X. J.; Steffen, J. M.

1985-01-01

Cardiovascular responses and fluid/electrolyte shifts seen during space flight are attributed to cephalad redistribution of vascular fluid. The antiorthostatic (AO) rat (suspended head down tilted, 15-20 deg) is used to model these responses. Current studies show that elevated blood pressures in A0 rats are sustained for periods up to seven days. Comparisons are made with presuspension rats. Increased blood pressure in head down tilted subjects suggests a specific response to A0 positioning, potentially relatable to cephalad fluid shift. To assess a role for hormonal regulation of sodium excretion, serum aldosterone levels were measured.

Cardiovascular alterations and multi organ dysfunction after birth asphyxia

PubMed Central

Polglase, Graeme R.; Ong, Tracey; Hillman, Noah H

2016-01-01

Synopsis The cardiovascular response to asphyxia involves redistribution of cardiac output to maintain oxygen delivery to critical organs such as the adrenal gland, heart and brain, at the expense of other organs such as the gut, kidneys and skin. This results in reduced perfusion and localized hypoxia/ischemia in these organs, which if severe, can result in multi-organ failure. Liver injury, coagulopathy, bleeding, thrombocytopenia, renal dysfunction, pulmonary and gastrointestinal injury all result from hypoxia, under-perfusion or both. Current clinical therapies need to be considered together with therapeutic hypothermia and cardiovascular recovery. PMID:27524448

Ocean warming expands habitat of a rich natural resource and benefits a national economy.

PubMed

Jansen, Teunis; Post, Søren; Kristiansen, Trond; Óskarsson, Guðmundur J; Boje, Jesper; MacKenzie, Brian R; Broberg, Mala; Siegstad, Helle

2016-10-01

Geographic redistribution of living natural resources changes access and thereby harvesting opportunities between countries. Internationally shared fish resources can be sensitive to shifts in the marine environment and this may have great impact on the economies of countries and regions that rely most heavily on fisheries to provide employment and food supply. Here we present a climate change-related biotic expansion of a rich natural resource with substantial economic consequences, namely the appearance of northeast Atlantic mackerel (Scomber scombrus) in Greenlandic waters. In recent years, the summer temperature has reached record highs in the Irminger Current, and this development has expanded the available and realized mackerel habitat in time and space. Observations in the Irminger Current in east Greenland in 2011 of this temperature-sensitive epipelagic fish were the first records so far northwest in the Atlantic. This change in migration pattern was followed by a rapid development of a large-scale fishery of substantial importance for the national economy of Greenland (23% of Greenland's export value of all goods in 2014). A pelagic trawl survey was conducted in mid-summer 2014 and the results showed that the bulk of ~1 million Mg (=t) of mackerel in the Irminger Current in southeast Greenland were located in the relatively warm (>8.5°C) surface layer. Mackerel was also observed in southwest Greenland. Finally, 15 CMIP5 Earth System Model projections of future marine climate were used to evaluate the epipelagic environment in Greenland. These projections for moderate and high CO 2 emission scenarios (representative concentration pathways [RCP] 4.5 and 8.5) suggest how the available mackerel habitat may expand further in space and time. Overall, our results indicate that, if the stock remains large, productive, and continues its current migration pattern, then climate change has provided Greenland with a new unique opportunity for commercial exploitation. However, positive cases like this should not be cherry-picked and misused as arguments against timely and effective mitigation of climate change. © 2016 by the Ecological Society of America.

Understanding performance limitation and suppression of leakage current or self-discharge in electrochemical capacitors: a review.

PubMed

Ike, Innocent S; Sigalas, Iakovos; Iyuke, Sunny

2016-01-14

Self-discharge is known to have considerable adverse effects on the performance and application of electrochemical capacitors (ECs). Thus, obtaining an understanding of EC self-discharge mechanism(s) and subsequent derivation and solution of EC models, subject to a particular mechanism or combination of mechanisms during charging, discharging and storage of the device, is the only way to solve problems associated with EC self-discharge. In this review, we summarize recent progress with respect to EC self-discharge by considering the two basic types, electric double-layer capacitors (EDLC) and pseudocapacitors, and their hybrids with their respective charge storage mechanisms, distinguishable self-discharge mechanisms, charge redistribution and charge/energy loss during self-discharge. It was clearly observed that most of the voltage reduction is not purely due to the self-discharge effect but is basically due to redistribution of charge carriers deep inside pores and can therefore be retrieved from a capacitor during long-time discharging. Tuning the self-discharge rate is therefore feasible for single-walled carbon nanotube (SWNT) ECs and can be achieved by simply adjusting the surface chemistry of the nanotubes. The effects of surface chemistry modification on EC self-discharge are very important in studying and suppressing the self-discharge process and will benefit potential applications of ECs with respect to energy retention. Self-discharge can be averted by the use of redox couples that are transformed to insoluble species via electrolysis and adsorbed onto the activated carbon electrode in redox-couple EDLCs, thus transforming the EDLC electrolyte into a material that can store charge. Self-discharge in ECs can also be successfully suppressed by utilizing an ion-interchange layer (ion-exchange membrane), separator or CuSO4 mobile electrolyte that can be converted into an insoluble species by electrolysis during the charge/discharge process. This will help in producing a modern-day blueprint for ECs with high capacitance and improved energy sustainability.

Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

DOE PAGES

Fu, Congsheng; Wang, Guiling; Goulden, Michael L.; ...

2016-05-17

Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site comparisons for contrasting climate regimes and multiple vegetation types via the integration of measurement and modeling. Here, we incorporated the HR scheme of Ryel et al. (2002) into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture themore » magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on land surface water and energy budgets, and to explore how the impact may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites with contrasting climate regimes and multiple vegetation types were studied, including the Wind River Crane site in Washington State, the Santa Rita Mesquite savanna site in southern Arizona, and six sites along the Southern California Climate Gradient. HR flux, evapotranspiration (ET), and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement matches of evapotranspiration, Bowen ratio, and soil moisture particularly during dry seasons. Lastly, our results also reveal that HR has important hydrological impact in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.« less

Helical undulator based on partial redistribution of uniform magnetic field

NASA Astrophysics Data System (ADS)

Balal, N.; Bandurkin, I. V.; Bratman, V. L.; Fedotov, A. E.

2017-12-01

A new type of helical undulator based on redistribution of magnetic field of a solenoid by ferromagnetic helix has been proposed and studied both in theory and experiment. Such undulators are very simple and efficient for promising sources of coherent spontaneous THz undulator radiation from dense electron bunches formed in laser-driven photo-injectors.

Hydraulic redistribution of soil water by neotropical savanna trees.

Treesearch

Fabian G. Scholz; Sandra J. Bucci; Guillermo Goldstein; et al.

2002-01-01

The magnitude and direction of water transport by the roots of eight dominant Brazilian savanna (Cerrado) allowed bidirectional measurements of sap flow. The patterns of sap flow observed during the dry season in species with dimorphic roots systems were consistent with the occurrence of hydraulic redistribution of soil water, the movement of water from moist to drier...

Redistributive Taxation vs. Education Subsidies: Fostering Equality and Social Mobility in an Intergenerational Model

ERIC Educational Resources Information Center

Schneider, Andrea

2010-01-01

Redistributive taxation and education subsidies are common policies intended to foster education attendance of poor children. However, this paper shows that in an intergenerational framework, these policies can raise social mobility only for some investment situations but not in general. I also study the impact of both policies on the aggregate…

NATIVE ROOT XYLEM EMBOLISM AND STOMATAL CLOSURE IN STANDS OF DOUGLAS-FIR AND PONDEROSA PINE: MITIGATION BY HYDRAULIC REDISTRIBUTION

EPA Science Inventory

Hydraulic redistribution (HR), the passive movement of water via roots from moist to drier portions of the soil, occurs in many ecosystems, influencing both plant and ecosystem-water use. We examined the effects of HR on root hydraulic functioning during drought in young and old-...

In situ separation of root hydraulic redistribution of soil water from liquid and vapor transport

EPA Science Inventory

Nocturnal increases in water potential (ψ) and water content () in the upper soil profile are often attributed to root water efflux into the soil, a process termed hydraulic lift or hydraulic redistribution (HR). We have previously reported HR values up to ~0.29 mm day-1 in the ...

Converging patterns of uptake and hydraulic redistribution of soil water in contrasting woody vegetation types.

Treesearch

F.C. Meinzer; J.R. Brooks; S. Bucci; G. Goldstein; F.G. Scholz; J.M. Arren

2004-01-01

We used concurrent measurements of soil water content and soil water potential (Ψsoil) to assess the effects of Ψsoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles at six sites characterized by differences in the types and amounts of woody vegetations and...

Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being.

PubMed

Pecl, Gretta T; Araújo, Miguel B; Bell, Johann D; Blanchard, Julia; Bonebrake, Timothy C; Chen, I-Ching; Clark, Timothy D; Colwell, Robert K; Danielsen, Finn; Evengård, Birgitta; Falconi, Lorena; Ferrier, Simon; Frusher, Stewart; Garcia, Raquel A; Griffis, Roger B; Hobday, Alistair J; Janion-Scheepers, Charlene; Jarzyna, Marta A; Jennings, Sarah; Lenoir, Jonathan; Linnetved, Hlif I; Martin, Victoria Y; McCormack, Phillipa C; McDonald, Jan; Mitchell, Nicola J; Mustonen, Tero; Pandolfi, John M; Pettorelli, Nathalie; Popova, Ekaterina; Robinson, Sharon A; Scheffers, Brett R; Shaw, Justine D; Sorte, Cascade J B; Strugnell, Jan M; Sunday, Jennifer M; Tuanmu, Mao-Ning; Vergés, Adriana; Villanueva, Cecilia; Wernberg, Thomas; Wapstra, Erik; Williams, Stephen E

2017-03-31

Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of biodiversity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals. Copyright © 2017, American Association for the Advancement of Science.

An upper bound on the second order asymptotic expansion for the quantum communication cost of state redistribution

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

Datta, Nilanjana, E-mail: n.datta@statslab.cam.ac.uk; Hsieh, Min-Hsiu, E-mail: Min-Hsiu.Hsieh@uts.edu.au; Oppenheim, Jonathan, E-mail: j.oppenheim@ucl.ac.uk

State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement. We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol ofmore » coherent state merging as a primitive.« less

Do substorms energise the ring current?

NASA Astrophysics Data System (ADS)

Sandhu, J. K.; Rae, J.; Freeman, M. P.; Forsyth, C.; Jackman, C. M.; Lam, M. M.

2017-12-01

The substorm phenomenon is a highly dynamic and variable process that results in the global reconfiguration and redistribution of energy within the magnetosphere. There are many open questions surrounding substorms, particularly how the energy released during a substorm is distributed throughout the magnetosphere, and how the energy loss varies from one substorm to the next. In this study, we explore whether energy lost during the substorm plays a role in energising the ring current. Using observations of the particle energy flux from RBSPICE/RBSP, we are able to quantitatively observe how the energy is distributed spatially and across the different ion species (H+, He+, and O+). Furthermore, we can observe how the total energy content of the ring current changes during the substorm process, using substorm phases defined by the SOPHIE algorithm. This analysis provides information on how the energy released from a substorm is partitioned throughout the magnetosphere, and on the processes determining the energy provided to the ring current. Overall, our results show that the substorm-ring current coupling is more complex than originally thought, and we discuss the reasons behind this complex response.

Calcium movement, graviresponsiveness and the structure of columella cells and columella tissues in roots of Allium cepa L

NASA Technical Reports Server (NTRS)

Moore, R.

1985-01-01

Roots of Allium cepa L. cv. Yellow are differentially responsive to gravity. Long (e.g. 40 mm) roots are strongly graviresponsive, while short (c.g. 4 mm) roots are minimally responsive to gravity. Although columella cells of graviresponsive roots are larger than those of nongraviresponsive roots, they partition their volumes to cellular organelles similarly. The movement of amyloplasts and nuclei in columella cells of horizontally-oriented roots correlates positively with the onset of gravicurvature. Furthermore, there is no significant difference in the rates of organellar redistribution when graviresponsive and nongraviresponsive roots are oriented horizontally. The more pronounced graviresponsiveness of longer roots correlates positively with (1) their caps being 9-6 times more voluminous, (2) their columella tissues being 42 times more voluminous, (3) their caps having 15 times more columella cells, and (4) their columella tissues having relative volumes 4.4 times larger than those of shorter, nongraviresponsive roots. Graviresponsive roots that are oriented horizontally are characterized by a strongly polar movement of 45Ca2+ across the root tip from the upper to the lower side, while similarly oriented nongraviresponsive roots exhibit only a minimal polar transport of 45Ca2+. These results indicate that the differential graviresponsiveness of roots of A. cepa is probably not due to either (1) ultrastructural differences in their columella cells, (2) differences in the rates of organellar redistribution when roots are oriented horizontally. Rather, these results indicate the graviresponsiveness may require an extensive columella tissue, which, in turn, may be necessary for polar movement of 45Ca2+ across the root tip.

Relative contribution of potential modes of surface dust lead contamination in the homes of boatyard caulkers.

PubMed

Untimanon, Orrapan; Geater, Alan; Chongsuvivatwong, Virasakdi; Saetia, Wiyada; Verkasalo, Pia K

2012-01-01

The aim of this study was to quantify the relative contributions to surface lead contamination of boat-caulkers' houses of three contamination modes, namely "take-home" lead from the caulker, "natural" spatial dispersal from boatyard to household and "redistribution" of accumulated lead-laden dust within the house. Boat-caulkers' houses situated in areas surrounding boat repair yards were recruited. Caulkers' houses that were located close together were divided into location-matched pairs, within which one was randomly assigned to be given a cleaning and designated a CL house, and the other was to be left uncleaned and designated a NCL house. Geographically isolated caulker's houses were randomly assigned to one of the two categories. The nearest non-boatyard worker's house (NB) was additionally recruited for each set. The surface lead loading rate (SLLR), defined as the mass of lead deposited in dust per unit area of surface per unit time, was measured over a period of 3 mo in all houses, and the data were modeled using linear mixed effects regression. Adjusted values of SLLR differed only slightly between CL and NCL houses (0.96 to 1.02 times) but were between 1.65 and 2.03 times higher in CL and NCL houses than in NB houses depending on proximity to the boatyard and between 2.12 and 2.61 times higher in houses within one km of a boatyard than in more distant houses depending on category of house. Newly deposited dust lead likely resulted from the take-home and spatial dispersion modes. The contribution of redistribution is very small.

Increased horizontal viewing zone angle of a hologram by resolution redistribution of a spatial light modulator.

PubMed

Takaki, Yasuhiro; Hayashi, Yuki

2008-07-01

The narrow viewing zone angle is one of the problems associated with electronic holography. We propose a technique that enables the ratio of horizontal and vertical resolutions of a spatial light modulator (SLM) to be altered. This technique increases the horizontal resolution of a SLM several times, so that the horizontal viewing zone angle is also increased several times. A SLM illuminated by a slanted point light source array is imaged by a 4f imaging system in which a horizontal slit is located on the Fourier plane. We show that the horizontal resolution was increased four times and that the horizontal viewing zone angle was increased approximately four times.

Coal-fired power generaion, new air quality regulations, and future U.S. coal production

USGS Publications Warehouse

Attanasi, E.D.; Root, D.H.

1999-01-01

Tighter new regulation of stack gas emissions and competition in power generation are driving electrical utilities to demand cleaner, lower sulfur coal. Historical data on sulfur content of produced coals shows little variability in coal quality for individual mines and individual coal-producing counties over relatively long periods of time. If coal-using power generators follow the compliance patterns established in Phase I of the 1990 Clean Air Act Amendments, then the industry's response to the tighter Phase II emissions standards will result in large amounts of coal production shifting from higher sulfur areas to areas with lower cost low sulfur coal. One reason this shift will likely occur is that currently only 30% of U.S. coal-fired electrical generating capacity is equipped with flue-gas scrubbers. In 1995, coal mines in the higher sulfur areas of the Illinois Basin and Northern and Central Appalachia employed 78% of all coal miners (>70,000 miners). A substantial geographical redistribution of the nation's coal supplies will likely lead to economic dislocations that will reach beyond local coal-producing areas.

Alfven Eigenmode Control in DIII-D

NASA Astrophysics Data System (ADS)

Hu, W.; Olofsson, E.; Welander, A.; van Zeeland, M.; Collins, C.; Heidbrink, W.

2017-10-01

Alfven eigenmodes (AE) driven by fast ions from neutral beam and ion cyclotron heating are common in present day tokamak plasmas and are expected to be destabilized by alpha particles in future burning plasma experiments. Because these waves have been shown to cause loss and redistribution of fast ions which can impact plasma performance and potentially device integrity, developing control techniques for AEs is of paramount importance. In the DIII-D plasma control system, spectral analysis of real-time ECE data is used as a monitor of AE amplitude, frequency, and location. These values are then used for feedback control of the neutral beam power to control Alfven waves and reduce fast ion loss. This work describes tests of AE control experiments in the current ramp up phase, during which multiple Alfven eigenmodes are typically unstable and fast ion confinement is degraded significantly. Comparisons of neutron emission and confined fast ion profiles with and without active AE control will be made. Work supported by the U.S. Dept. of Energy under Award Number DE-FC02-04ER54698.