The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator.

Science.gov (United States)

Grants, Jennifer M; Goh, Grace Y S; Taubert, Stefan

2015-02-27

The Mediator multiprotein complex ('Mediator') is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Stability of stagnation via an expanding accretion shock wave

International Nuclear Information System (INIS)

Velikovich, A. L.; Giuliani, J. L.; Murakami, M.; Taylor, B. D.; Zalesak, S. T.; Iwamoto, Y.

2016-01-01

Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

Stability of stagnation via an expanding accretion shock wave

Energy Technology Data Exchange (ETDEWEB)

Velikovich, A. L.; Giuliani, J. L. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Taylor, B. D. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375 (United States); Zalesak, S. T. [Berkeley Research Associates, Beltsville, Maryland 20705 (United States); Iwamoto, Y. [Ehime University, Matsuyama, Ehime Pref. 790-8577 (Japan)

2016-05-15

Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

Stability of stagnation via an expanding accretion shock wave

Science.gov (United States)

Velikovich, A. L.; Murakami, M.; Taylor, B. D.; Giuliani, J. L.; Zalesak, S. T.; Iwamoto, Y.

2016-05-01

Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

Turbulence modeling and surface heat transfer in a stagnation flow region

Science.gov (United States)

Wang, C. R.; Yeh, F. C.

1987-01-01

Analysis for the turbulent flow field and the effect of freestream turbulence on the surface heat transfer rate of a stagnation flow is presented. The emphasis is on modeling and its augmentation of surface heat transfer rate. The flow field considered is the region near the forward stagnation point of a circular cylinder in a uniform turbulent mean flow.

Reference Structures: Stagnation, Progress, and Future Challenges.

Science.gov (United States)

Greenberg, Jane

1997-01-01

Assesses the current state of reference structures in online public access catalogs (OPACs) in a framework defined by stagnation, progress, and future challenges. Outlines six areas for reference structure development. Twenty figures provide illustrations. (AEF)

K-Cl Cotransporter 2-mediated Cl- Extrusion Determines Developmental Stage-dependent Impact of Propofol Anesthesia on Dendritic Spines.

Science.gov (United States)

Puskarjov, Martin; Fiumelli, Hubert; Briner, Adrian; Bodogan, Timea; Demeter, Kornel; Lacoh, Claudia-Marvine; Mavrovic, Martina; Blaesse, Peter; Kaila, Kai; Vutskits, Laszlo

2017-05-01

General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABAA)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABAA)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. The KCC2-dependent developmental increase in the efficacy of GABAA-mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

Effect of ablation geometry on the formation of stagnation layer in laterally colliding plasmas

International Nuclear Information System (INIS)

Mondal, Alamgir; Singh, Rajesh K.; Kumar, Ajai

2015-01-01

Interaction between two parallel propagating plasma plumes have been investigated in two different ablation schemes e.g. laser-blow-off (LBO) of thin film and conventional laser ablation (LPP). Fast imagine technique is used to study the dynamical and geometrical aspect of seed plasmas and induced stagnation layer in between the two expanding seed plasmas. Interaction between the energetic particles, coming from the seed plasmas are responsible for formation of stagnation layer. It has been found that geometrical shape, size, kinetic energy and divergence of plasma plumes are highly dependent on the ablation geometry. These variations in seed plasmas initiate the significant differences in the stagnation layer formed by LBO and LPP geometry. In this presentation, characteristic feature of stagnation layer which includes density, initiation time, emissive life time and geometry in both LBO and LPP geometry are briefly discussed. A comparative study of present results suggests that the plume composition and directionality of seed plasma play crucial role in mechanistic aspect of stagnation layer. (author)

Nested separatrices in simple shear flows: the effect of localized disturbances on stagnation lines

OpenAIRE

Wilson, M.C.T.; Gaskell, P.H.; Savage, M.D.

2005-01-01

The effects of localized two-dimensional disturbances on the structure of shear flows featuring a stagnation line are investigated. A simple superposition of a planar Couette flow and Moffatt's [J. Fluid Mech. 18, 1--18 (1964)] streamfunction for the decay of a disturbance between infinite stationary parallel plates shows that in general the stagnation line is replaced by a chain of alternating elliptic and hyperbolic stagnation points with a separation equal to 2.78 times the half-gap betwee...

Public debt, secular stagnation and functional finance

DEFF Research Database (Denmark)

Skott, Peter

2016-01-01

Fiscal policy and public debt may be required to maintain full employment and avoid secular stagnation. This conclusion emerges from a range of different models, including OLG specifications and stock-flow consistent (post-) Keynesian models. One of the determinants of the required long-run debt ...

K-Cl Cotransporter 2–mediated Cl− Extrusion Determines Developmental Stage–dependent Impact of Propofol Anesthesia on Dendritic Spines

KAUST Repository

Puskarjov, Martin; Fiumelli, Hubert; Briner, Adrian; Bodogan, Timea; Demeter, Kornel; Lacoh, Claudia Marvine; Mavrovic, Martina; Blaesse, Peter; Kaila, Kai; Vutskits, Laszlo

2017-01-01

Background: General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABA A)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). Methods: In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABA A)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. Results: The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl - transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. Conclusions: The KCC2-dependent developmental increase in the efficacy of GABA A -mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

K-Cl Cotransporter 2–mediated Cl− Extrusion Determines Developmental Stage–dependent Impact of Propofol Anesthesia on Dendritic Spines

KAUST Repository

Puskarjov, Martin

2017-03-16

Background: General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABA A)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). Methods: In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABA A)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. Results: The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl - transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. Conclusions: The KCC2-dependent developmental increase in the efficacy of GABA A -mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

Energy-political stagnation or innovation

International Nuclear Information System (INIS)

Kitschelt, H.

1982-01-01

The author discusses the enquete report 1980. He makes an inventory for a political and sociological interpretation of the interim report between meaningful innovation and political insignificance as well as intellectual stagnation. The report is considered as an indicator for the transformation of the energy-political arena in the Federal Republic of Germany over the last years. ''Stagnation'' or ''innovation'' of the argumentation patterns in the report of the enquete commission relate to the question whether the analyses in that document are rather a brake or a motor to a shift of political perspectives in energy policy. A progress can be seen in the report regarding political debate about energy-options in the semi-official political spectrum of the Federal Republic of Germany, in as far as differring options of energy-political development are being acknowledged for the first time. At the same time, debate inside the commission directs the attention to issues of institutional policy in the energy sector. Considering the fights within the commission before the report was agreed on, it seems doubtful if its proposals for compromise will prove a sound political basis. The tensions inside the commission are just a first sign of the power conflicts due above all if the recommendations for energy conservation are intransigently carried out. (orig./HSCH) [de

Solar wind stagnation near comets

International Nuclear Information System (INIS)

Galeev, A.A.; Cravens, T.E.; Gombosi, T.I.

1983-03-01

The nature of the solar wind flow near comets is examined analytically. In particular, the typical values for the stagnation pressure and magnetic barrier strength are estimated, taking into account the magnetic field line tension and the charge exchange cooling of the mass loaded solar wind. Knowledge of the strength of the magnetic barrier is required in order to determine the location of the contact discontinuity which separates the contaminated solar wind plasma and the outflowing plasma of the cometary ionosphere. (author)

THERMOSS: A thermohydraulic model of flow stagnation in a horizontal fuel channel

International Nuclear Information System (INIS)

Gulshani, P.; Caplan, M.Z.; Spinks, N.J.

1984-01-01

A model, called THERMOSS, is developed to compute the duration of stagnation in a CANDU reactor fuel channel with subcooled, stagnant initial conditions. The model solves, in closed form, the one dimensional, two-fluid conservation equations. In the computation of the duration of stagnation, the channel water level is an important intermediate variable because it determines the amount of steam production. A feature of the model is that water level is determined by a momentum balance between frictional pressure drop in the steam phase and hydrostatic head in the liquid phase. This is in contrast to an ealier model in which the level was determined from mass balance considerations. A satisfactory agreement between the predicted and experimentally observed channel water level and duration of stagnation is obtained. (orig.)

Aggregate demand, functional finance and secular stagnation

DEFF Research Database (Denmark)

Skott, Peter

2016-01-01

This paper makes three main points. Fiscal policy, first, may be needed in the long run to maintain full employment and avoid secular stagnation. If fiscal policy is used in this way, second, the long-run debt ratio depends (i) inversely on the rate of growth, (ii) inversely on government consump...

Effect of bed configuration on pebble flow uniformity and stagnation in the pebble bed reactor

International Nuclear Information System (INIS)

Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jiang, Shengyao

2014-01-01

Highlights: • Pebble flow uniformity and stagnation characteristics are very important for HTR-PM. • Arc- and brachistochrone-shaped configuration effects are studied by DEM simulation. • Best bed configurations with uniform flow and no stagnated pebbles are suggested. • Detailed quantified characteristics of bed configuration effects are shown for explanation. - Abstract: Pebble flow uniformity and stagnation characteristics are very important for the design of pebble bed high temperature gas-cooled reactor. Pebble flows inside some specifically designed contraction configurations of pebble bed are studied by discrete element method. The results show the characteristics of stagnation rates, recycling rates, radial distribution of pebble velocity and residence time. It is demonstrated clearly that the bed with a brachistochrone-shaped configuration achieves optimum levels of flow uniformity and recycling rate concentration, and almost no pebbles are stagnated in the bed. Moreover, the optimum choice among the arc-shaped bed configurations is demonstrated too. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity. In addition, a good design of the pebble bed configuration is suggested

Implications of the stagnation line model for energy input through the dayside magnetopause

International Nuclear Information System (INIS)

Pudovkin, M.I.; Semenov, V.S.; Heyn, M.F.; Biernat, H.K.

1986-01-01

Based on the formation of a stagnation line at the magnetopause the electromagnetic energy transport from the solar wind into the dayside magnetosphere is analyzed. The resulting energy flux is analyzed. The resulting energy flux is proportional to v/sub infinity/B/sub infinity/sin 2 (theta/sub infinity/-phi/sub infinity/), where v/sub infinity/ and B/sub infinity/ are the solar wind speed and magnetic field and theta/sub infinity/-phi/sub s/infinity is the angle between the IMF and the stagnation line projected into the interplanetary space. A stagnation line parallel to the separator gives approximately the sin 4 (theta/sub infinity//2) energy flux dependence of Akasofu's epsilon-index

Wage Dispersion, Public Sector Wages and the Stagnating Danish Gender Wage Gap

DEFF Research Database (Denmark)

Gupta, Nabanita Datta; Oaxaca, Ronald L.; Smith, Nina

1998-01-01

The gender wage gap in Denmark has virtually stagnated since the early 70s. This study examines whether this stagnation is mainly due to a changing wage dispersion or to changing prices on observed and unobserved skills. Since about half the female labour force is employed in the public sector....... These techniques are applied to a sample of Danish wage earners in the period 1983-94. The decomposition results suggest different explanations behind the stagnation of the gender wage gap in the public and private sectors. The development in average public sector wages is calculated assuming observed......, the impact of the changing wage structure between the public and private sectors is investigated. The analysis is based on the Juhn-Murphy-Pierce decomposition applied to a pooled wage regression model. The equivalence between the former and the Oaxaca-Ransom generalized wage decomposition is established...

Unequally redundant RCD1 and SRO1 mediate stress and developmental responses and interact with transcription factors

NARCIS (Netherlands)

Jaspers, P.; Blomster, T.; Brosché, M.; Salojärvi, J.; Ahlfors, R.; Vainonen, J.P.; Reddy, R.A.; Immink, G.H.; Angenent, G.C.; Turck, F.; Overmyer, K.; Kangasjärvi, J.

2009-01-01

RADICAL-INDUCED CELL DEATH1 (RCD1) is an important regulator of stress and hormonal and developmental responses in Arabidopsis thaliana. Together with its closest homolog, SIMILAR TO RCD-ONE1 (SRO1), it is the only Arabidopsis protein containing the WWE domain, which is known to mediate

Swedish district heating—A system in stagnation: Current and future trends in the district heating sector

International Nuclear Information System (INIS)

Magnusson, Dick

2012-01-01

This paper argues that Sweden’s old and established district heating sector is heading into a stagnation phase. The aim is to analyse the factors influencing this development as well as the strategies used by involved parties to prevent stagnation. Using large technical system theory, I analyse internal and external factors potentially causing stagnation. The most obvious external factors are: an increase in the number of energy-efficient buildings, in response to stricter energy policies, which reduces the future potential for district heating in new and existing buildings; climate change; competition from other heating systems; and market saturation in the key sector, multi-dwelling buildings. The main internal factor is changed business strategies following electricity market deregulation, when energy companies were supposed to be run on businesslike terms. I also argue that stagnation can be defined as occurring when the key measure feature of a system, in this case, heat load is starting to stagnate or decline, even though the trend is positive in other areas. The strategies for avoiding stagnation are various forms of broadening scope, primarily by focusing more on electricity production by building combined heat and power plants, or using the alternative value of the technical system for new applications. - Highlights: ► The Swedish district heating sector is heading into a stage of stagnation. ► The main reasons are: climate change, competition and energy efficient buildings. ► Strategies to change trend: broadening of scope by focusing on electricity in CHP plants. ► Contribution to Large Technical Systems—theory and the later phases of system development.

Developmental environment mediates male seminal protein investment in Drosophila melanogaster.

Science.gov (United States)

Wigby, Stuart; Perry, Jennifer C; Kim, Yon-Hee; Sirot, Laura K

2016-03-01

Males of many species fine-tune their ejaculates in response to sperm competition risk. Resource availability and the number of competitors during development can also strongly influence sperm production. However, despite the key role of seminal proteins in mediating reproductive processes, it is unclear whether seminal protein investment is dependent on the developmental environment.We manipulated the developmental environment of Drosophila melanogaster by rearing flies at low and high density. As expected, this resulted in large and small (i.e. high and low condition) adult phenotypes, respectively.As predicted, large males produced more of two key seminal proteins, sex peptide (SP) and ovulin, and were more successful at obtaining matings with both virgin and previously mated females. However, there was only a weak and non-significant trend for large males to transfer more absolute quantities of SP at mating, and thus, small males ejaculated proportionally more of their stored accessory gland SP resources.Males transferred more receptivity-inhibiting SP to large females. Despite this, large females remated more quickly than small females and thus responded to their developmental environment over and above the quantity of SP they received.The results are consistent with two non-mutually exclusive hypotheses. First, flies might respond to condition-dependent reproductive opportunities, with (i) small males investing heavily in ejaculates when mating opportunities arise and large males strategically partitioning SP resources and (ii) small females remating at reduced rates because they have higher mating costs or need to replenish sperm less often.Second, flies may be primed by their larval environment to deal with similar adult population densities, with (i) males perceiving high density as signalling increased competition, leading small males to invest proportionally more SP resources at mating and (ii) females perceiving high density as signalling abundant

RELAP4 stagnation properties option

International Nuclear Information System (INIS)

DeYoung, T.L.

1979-01-01

The stagnation properties option in RELAP4/MOD6 was completely reviewed, from theoretical foundation to code application. The result of this investigation was the identification of a fundamental mismatch between the essentially homogeneous, equilibrium-based, RELAP4 code and the nonhomogeneous and/or nonequilibrium critical flow models imposed on the code. By continuously monitoring fluid Mach numbers and adjusting flow areas such that sonic velocity was never exceeded, the mismatch could be accommodated. This approach was implemented, found to work correctly, and will be incorporated into the MOD7 version of the code

Investigation of Hypersonic Laminar Heating Augmentation in the Stagnation Region

Science.gov (United States)

Marineau, Eric C.; Lewis, Daniel R.; Smith, Michael S.; Lafferty, John F.; White, Molly E.; Amar, Adam J.

2012-01-01

Laminar stagnation region heating augmentation is investigated in the AEDC Tunnel 9 at Mach 10 by performing high frequency surface pressure and heat transfer measurements on the Orion CEV capsule at zero degree angle-of-attack for unit Reynolds numbers between 0.5 and 15 million per foot. Heating augmentation increases with Reynolds number, but is also model size dependent as it is absent on a 1.25-inch diameter model at Reynolds numbers where it reaches up to 15% on a 7-inch model. Heat transfer space-time correlations on the 7-inch model show that disturbances convect at the boundary layer edge velocity and that the streamwise integral scale increases with distance. Therefore, vorticity amplification due to stretching and piling-up in the stagnation region appears to be responsible for the stagnation point heating augmentation on the larger model. This assumption is reinforced by the f(exp -11/3) dependence of the surface pressure spectrum compared to the f(exp -1) dependence in the free stream. Vorticity amplification does not occur on the 1.25- inch model because the disturbances are too large. Improved free stream fluctuation measurements will be required to determine if significant vorticity is present upstream or mostly generated behind the bow shock.

Effect of outer stagnation pressure on jet structure in supersonic coaxial jet

International Nuclear Information System (INIS)

Kim, Myoung Jong; Woo, Sang Woo; Lee, Byeong Eun; Kwon, Soon Bum

2001-01-01

The characteristics of dual coaxial jet which composed of inner supersonic nozzle of 26500 in constant expansion rate with 1.91 design Mach number and outer converging one with 40 .deg. C converging angle with the variation of outer nozzle stagnation pressure are experimentally investigated in this paper. In which the stagnation pressure for the inner supersonic nozzle is 750kPa thus, the inner jet leaving the nozzle is slightly underexpanded. The plenum pressure of outer nozzle are varied from 200 to 600kPa. Flow visualizations by shadowgraph method, impact pressure and centerline static pressure measurements of dual coaxial jet are presented. The results show that the presence of outer jet affects significantly the structures and pressure distributions of inner jet. And outer jet causes Mach disk which does not appear for the case of single jet stream. As the stagnation pressure of outer jet increases, impact pressure undulation is severe, but the average impact pressure keeps high far downstream

Adhesion of leukocytes under oscillating stagnation point conditions: a numerical study.

Science.gov (United States)

Walker, P G; Alshorman, A A; Westwood, S; David, T

2002-01-01

Leukocyte recruitment from blood to the endothelium plays an important role in atherosclerotic plaque formation. Cells show a primary and secondary adhesive process with primary bonds responsible for capture and rolling and secondary bonds for arrest. Our objective was to investigate the role played by this process on the adhesion of leukocytes in complex flow. Cells were modelled as rigid spheres with spring like adhesion molecules which formed bonds with endothelial receptors. Models of bond kinetics and Newton's laws of motion were solved numerically to determine cell motion. Fluid force was obtained from the local shear rate obtained from a CFD simulation of the flow over a backward facing step.In stagnation point flow the shear rate near the stagnation point has a large gradient such that adherent cells in this region roll to a high shear region preventing permanent adhesion. This is enhanced if a small time dependent perturbation is imposed upon the stagnation point. For lower shear rates the cell rolling velocity may be such that secondary bonds have time to form. These bonds resist the lower fluid forces and consequently there is a relatively large permanent adhesion region.

Invalidating stagnation theory for family owned businesses : comparing family-to-family and third party ownership transfers

NARCIS (Netherlands)

Alija Ibrahimovic; Lex van Teeffelen; Roger Heaver

2015-01-01

Miller, Le Breton-Miller and Scholnick (2008) summarize and discuss two major perspectives constructed from the literature on family owned businesses (FOBs): stewardship and stagnation theory. In this paper the stagnation theory is being put to the test on Dutch small/medium enterprises (SMEs).

Perceived Parenting Styles Fail to Mediate between Anxiety and Attachment Styles in Adult Siblings of Individuals with Developmental Disabilities

Science.gov (United States)

O'Neill, Linda P.; Murray, Lindsay E.

2016-01-01

Adult siblings of individuals with developmental disabilities often experience higher levels of anxiety than individuals in the general population. The present study tested whether perceived parenting could mediate the relationship between attachment styles and anxiety in the sibling group compared to a control group. Little association was found…

The role of empowerment in youth development: a study of sociopolitical control as mediator of ecological systems' influence on developmental outcomes.

Science.gov (United States)

Christens, Brian D; Peterson, N Andrew

2012-05-01

Empowerment has become an influential concept and theoretical framework for social policy and practice. Still, relatively little is known about the roles that empowerment plays in the ecology of human development, particularly among young people. This article reports results of a study of psychological empowerment among young people, using data from 629 high school students (65.8% female; 96.5% non-white). Using a path analysis, we examined the role of perceived sociopolitical control--an indicator of the intrapersonal component of psychological empowerment--as a mediator between ecological support systems and developmental outcomes. Findings confirmed that social support in family, peer, and school settings, and family cohesion positively predict self-esteem and perceived school importance, which, in turn, have protective effects on psychological symptoms, violent behaviors and substance use. Sociopolitical control was found to mediate the relationships between ecological supports and risk factors and developmental outcomes, leading to the conclusion that perceived efficacy in the sociopolitical domain, and youth empowerment, more generally, should be considered as core elements of the ecology of human development. Policy and practice aimed at promoting positive developmental outcomes and preventing risk behaviors should take their relationship to sociopolitical control into account.

Developmental Scaffolding

DEFF Research Database (Denmark)

Giorgi, Franco; Bruni, Luis Emilio

2015-01-01

. Within the developmental hierarchy, each module yields an inter-level relationship that makes it possible for the scaffolding to mediate the production of selectable variations. Awide range of genetic, cellular and morphological mechanisms allows the scaffolding to integrate these modular variations...... to the complexity of sign recognition proper of a cellular community. In this semiotic perspective, the apparent goal directness of any developmental strategy should no longer be accounted for by a predetermined genetic program, but by the gradual definition of the relationships selected amongst the ones...

Perceived Parenting Styles Fail to Mediate Between Anxiety and Attachment Styles in Adult Siblings of Individuals with Developmental Disabilities.

Science.gov (United States)

O'Neill, Linda P; Murray, Lindsay E

2016-09-01

Adult siblings of individuals with developmental disabilities often experience higher levels of anxiety than individuals in the general population. The present study tested whether perceived parenting could mediate the relationship between attachment styles and anxiety in the sibling group compared to a control group. Little association was found between perceived parenting and attachment styles or anxiety for the siblings but there were robust and expected findings for the control. Adult attachment-related-anxiety was a significant unique predictor of anxiety in the sibling group but there was no mediational role for perceived parenting. Conversely, the majority of parenting styles significantly mediated the relationship between attachment and anxiety in the control. Implications for the atypical findings in the sibling group are discussed.

THE EFFECTS OF DEVELOPMENTAL AND RATIONAL SUBCULTURES ON ENTREPRENEURIAL BEHAVIORS: THE MEDIATING ROLE OF PERCEIVED ENVIRONMENTAL UNCERTAINTY

OpenAIRE

Irfan Akkoc; Abdullah Caliskan; Omer Turunc

2012-01-01

The aim of this study is to investigate the effect of developmental and rational culture on the employees’ entrepreneurial behaviors and the mediating role of the perceived environmental uncertainty on this effect. The relationship between the aforementioned variables is analyzed by using a set of statistical techniques, i.e., factor analysis, regression analysis, and sobel tests. The data used in the analysis is obtained through questionnaires filled out by 651 employees of the private firms...

Changes of the corrosion potential of iron in stagnation and flow conditions and their relationship with metal release.

Science.gov (United States)

Fabbricino, Massimiliano; Korshin, Gregory V

2014-10-01

This study examined the behavior of corrosion potential (Ecorr) of iron exposed to drinking water during episodes of stagnation and flow. These measurements showed that during stagnation episodes, Ecorr values decrease prominently and consistently. This decrease is initially rapid but it becomes slower as the stagnation time increases. During flow episodes, the Ecorr values increase and reach a quasi-steady state. Experiments with varying concentrations of dissolved oxygen showed that the decrease of Ecorr values characteristic for stagnation is likely to be associated with the consumption of dissolved oxygen by the exposed metal. The corrosion potential of iron and its changes during stagnation were sensitive to the concentrations of sulfate and chloride ions. Measurements of iron release showed that both the absolute values of Ecorr measured prior to or after stagnation episodes were well correlated with the logarithms of concentrations of total iron. The slope of this dependence showed that the observed correlations between Ecorr values and Fe concentrations corresponded to the coupling between the oxidant consumption and changes of Fe redox status. These results demonstrate that in situ Ecorr measurements can be a sensitive method with which to ascertain effects of hydrodynamic conditions and short-term variations of water chemistry on metal release and corrosion in drinking water. This approach is valuable practically because Ecorr measurements are precise, can be carried out in situ with any desired time resolution, do not affect the state of exposed surface in any extent and can be carried out with readily available equipment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Variations in the Spatial Distribution of Areas of Economic Growth and Stagnation in Poland: Determinants and Consequences

Directory of Open Access Journals (Sweden)

Churski Paweł

2014-06-01

Full Text Available This study seeks to identify the spatial distribution of and changes in areas of economic growth and stagnation in Poland resulting from spatial differences in the process of the country’s socio-economic advancement. The research covered two spatial systems, NUTS 2 and NUTS 4, and embraced the following steps: (1 identification of the spatial distribution of areas of economic growth and stagnation, by region and subregion, and of its determinants; (2 analysis of variations in the spatial distribution of areas of economic growth and stagnation, by region and subregion, and of its consequences; and (3 conclusions from the development trajectories identified and recommendations for intervention measures to be taken under cohesion policy.

Estimation of Centers and Stagnation points in optical flow fields

DEFF Research Database (Denmark)

Larsen, Rasmus

1997-01-01

In a topological sense fluid flows are characterised by their stagnation points. Given a temporal sequence of images of fluids we will consider the application of local polynomials to the estimation of smooth fluid flow fields. The normal flow at intensity contours is estimated from the local dis...

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

Science.gov (United States)

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%.

[The Mediating Role of Parenting Self-Efficacy on Parenting Stress and Quality of Life in Parents of Young Children With Developmental Delay].

Science.gov (United States)

Sun, Yi; Wu, Wei-Wen; Lin, Kuan-Chia; Chen, Jo-Lin

2016-10-01

Previous studies indicate that parents of developmentally delayed children have higher parenting stress (PS) and lower quality of life (QoL) than parents of healthy children. Parenting self-efficacy (PSE) may mediate the effects of PS on the QoL of parents. The present study explores the mediating role of PSE between PS and the QoL of parents of developmentally delayed children and compares the differences in several variables between fathers and mothers. A cross-sectional research design was used to study a sample of 70 parent dyads. Instruments used were the Basic Information Form, Parenting Stress Index Short Form (PSI-SF), Parenting Self-efficacy Scale (PSE Scale), and World Health Organization Quality of Life-BREF Taiwan version (WHOQOL-BREF). (1) Participants had a moderate level of QoL, PS, and PSE. (2) The PS of participants was significantly and negatively correlated with both QoL and PSE while their PSE was significantly and positively correlated with QoL. (3) The PSE of the fathers completely mediated the effects of PS on their QoL (p accounting for 62.2% of observed variation, while the PSE of the mothers partially mediated the effects of PS on their QoL (p accounting for 59.5% of observed variation. PSE was identified as the mediator between PS and QoL in both fathers and mothers. The PSE of the fathers completely mediated the effect of PS on QoL, while the PSE of the mothers partially mediated the effect of PS on QoL. Further research that explores the factors that affect the QoL of parents and then uses the results to develop interventions to enhance the PSE of parents, especially fathers, is recommended.

Stagnation and interpenetration of laser-created colliding plasmas

Energy Technology Data Exchange (ETDEWEB)

Pollaine, S.M.; Albritton, J.R.; Kauffman, R.; Keane, C.J. (Lawrence Livermore National Lab., CA (USA)); Berger, R.L.; Bosch, R.; Delameter, N.D.; Failor, B.H. (KMS Fusion, Inc., Ann Arbor, MI (USA))

1990-11-05

A KMS laser experiment collides Aluminum (A1) and Magnesium (Mg) plasmas. The measurements include electron density, time and space resolved Ly-alpha and He-alpha lines of Al and Mg, and x-ray images. These measurements were analyzed with a hydrodynamic code, LASNEX, and a special two-fluid code OFIS. The results strongly suggest that at early times, the Al interpenetrates the counterstreaming Mg and deposits in the dense Mg region. At late times, the Al plasma stagnates against the Mg plasma.

l-Ergothioneine improves the developmental potential of in vitro sheep embryos without influencing OCTN1-mediated cross-membrane transcript expression.

Science.gov (United States)

Mishra, A; Reddy, I J; Dhali, A; Javvaji, P K

2018-04-02

SummaryThe objective of the study was to investigate the effect of l-ergothioneine (l-erg) (5 mM or 10 mM) supplementation in maturation medium on the developmental potential and OCTN1-dependant l-erg-mediated (10 mM) change in mRNA abundance of apoptotic (Bcl2, Bax, Casp3 and PCNA) and antioxidant (GPx, SOD1, SOD2 and CAT) genes in sheep oocytes and developmental stages of embryos produced in vitro. Oocytes matured with l-erg (10 mM) reduced their embryo toxicity by decreasing intracellular ROS and increasing intracellular GSH in matured oocytes that in turn improved developmental potential, resulting in significantly (P l-erg without change in maturation rate. l-Erg (10 mM) treatment did not influence the mRNA abundance of the majority of apoptotic and antioxidant genes studied in the matured oocytes and developmental stages of embryo. A gene expression study found that the SLC22A4 gene that encodes OCTN1, an integral membrane protein and specific transporter of l-erg was not expressed in oocytes and developmental stages of embryos. Therefore it was concluded from the study that although there was improvement in the developmental potential of sheep embryos by l-erg supplementation in maturation medium, there was no change in the expression of the majority of the genes studied due to the absence of the SLC22A4 gene in oocytes and embryos that encode OCTN1, which is responsible for transportation of l-erg across the membrane to alter gene expression.

Safe, Non-Corrosive Dielectric Fluid for Stagnating Radiator Thermal Control System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Paragon proposes to develop a single-loop, non-toxic, stagnating active pumped loop thermal control design for NASA's Orion or Lunar Surface Access Module (LSAM)...

Prediction and experimental validation of stagnation temperature attained by a solar cooker of hot box type

Energy Technology Data Exchange (ETDEWEB)

Narasimha Rao, A. V; Srikrishna, D. V. N [Warangal (India)

2000-07-01

A hot box type solar cooker, having double glass covers and a plane mirror reflector, is tested for stagnation temperature. A computer code is developed based on the analytical model proposed by Vaishya et. al. The global and beam components of solar radiation measured at Warangal are made use to predict the stagnation temperature of the cooker. The observed values of stagnation temperature at Warangal are compared with those of predicted values. A good agreement of the measured and observed values of the stagnation temperature is observed during the afternoon period. The lag in the observed values during the forenoon may be due to thermal inertia of the cooker. [Spanish] Se probo una estufa solar de tipo caja caliente con cubiertas dobles de vidrio y un espejo reflector plano para medir la temperatura de estancamiento. Se desarrollo un codigo de computacion basado en el modelo analitico propuesto por Vaishya et. al. Los componentes de la radiacion solar globales y de rayo medidos en Warangal se usan para predecir la temperatura de estancamiento de la estufa. Los valores observados de la temperatura de estancamiento en Warangal se comparan con los valores predichos. Se aprecia una buena concidencia de los valores medidos y observados de la temperatura de estancamiento durante el periodo de la tarde. El retraso de los valores observados durante la manana puede ser debido a la inercia termica de la estufa.

Modeling of Aerobrake Ballute Stagnation Point Temperature and Heat Transfer to Inflation Gas

Science.gov (United States)

Bahrami, Parviz A.

2012-01-01

A trailing Ballute drag device concept for spacecraft aerocapture is considered. A thermal model for calculation of the Ballute membrane temperature and the inflation gas temperature is developed. An algorithm capturing the most salient features of the concept is implemented. In conjunction with the thermal model, trajectory calculations for two candidate missions, Titan Explorer and Neptune Orbiter missions, are used to estimate the stagnation point temperature and the inflation gas temperature. Radiation from both sides of the membrane at the stagnation point and conduction to the inflating gas is included. The results showed that the radiation from the membrane and to a much lesser extent conduction to the inflating gas, are likely to be the controlling heat transfer mechanisms and that the increase in gas temperature due to aerodynamic heating is of secondary importance.

Using absolute x-ray spectral measurements to infer stagnation conditions in ICF implosions

Science.gov (United States)

Patel, Pravesh; Benedetti, L. R.; Cerjan, C.; Clark, D. S.; Hurricane, O. A.; Izumi, N.; Jarrott, L. C.; Khan, S.; Kritcher, A. L.; Ma, T.; Macphee, A. G.; Landen, O.; Spears, B. K.; Springer, P. T.

2016-10-01

Measurements of the continuum x-ray spectrum emitted from the hot-spot of an ICF implosion can be used to infer a number thermodynamic properties at stagnation including temperature, pressure, and hot-spot mix. In deuterium-tritium (DT) layered implosion experiments on the National Ignition Facility (NIF) we field a number of x-ray diagnostics that provide spatial, temporal, and spectrally-resolved measurements of the radiated x-ray emission. We report on analysis of these measurements using a 1-D hot-spot model to infer thermodynamic properties at stagnation. We compare these to similar properties that can be derived from DT fusion neutron measurements. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Growth or stagnation in pre-industrial Britain? A revealed income growth approach

DEFF Research Database (Denmark)

Groth, Christian; Persson, Karl Gunnar

2016-01-01

The extent of growth in pre-industrial Europe in general and in Britain in particular has attracted intense scholarly focus. Growth or Malthusian stagnation? No consensus has evolved. Reconstructions of national income from 1300 and up to the Industrial Revolution come to opposing conclusions...

What Explains the Stagnation of Female Labor Force Participation in Urban India?

NARCIS (Netherlands)

Klasen, S.; Pieters, J.

2015-01-01

Female labor force participation rates in urban India between 1987 and 2011 are surprisingly low and have stagnated since the late 1980s. Despite rising growth, fertility decline, and rising wage and education levels, married women's labor force participation hovered around 18 percent. Analysis of

Modeling study of rarefied gas effects on hypersonic reacting stagnation flows

Science.gov (United States)

Wang, Zhihui; Bao, Lin

2014-12-01

Recent development of the near space hypersonic sharp leading vehicles has raised a necessity to fast and accurately predict the aeroheating in hypersonic rarefied flows, which challenges our understanding of the aerothermodynamics and aerothermochemistry. The present flow and heat transfer problem involves complex rarefied gas effects and nonequilibrium real gas effects which are beyond the scope of the traditional prediction theory based on the continuum hypothesis and equilibrium assumption. As a typical example, it has been found that the classical Fay-Riddell equation fails to predict the stagnation point heat flux, when the flow is either rarefied or chemical nonequilibrium. In order to design a more general theory covering the rarefied reacting flow cases, an intuitive model is proposed in this paper to describe the nonequilibrium dissociation-recombination flow along the stagnation streamline towards a slightly blunted nose in hypersonic rarefied flows. Some characteristic flow parameters are introduced, and based on these parameters, an explicitly analytical bridging function is established to correct the traditional theory to accurately predict the actual aeroheating performance. It is shown that for a small size nose in medium density flows, the flow at the outer edge of the stagnation point boundary layer could be highly nonequilibrium, and the aeroheating performance is distinguished from that of the big blunt body reentry flows at high altitudes. As a result, when the rarefied gas effects and the nonequilibrium real gas effects are both significant, the classical similarity law could be questionable, and it is inadequate to directly analogize results from the classical blunt body reentry problems to the present new generation sharp-leading vehicles. In addition, the direct simulation Monte Carlo method is also employed to validate the conclusion.

Efficient solution to the stagnation problem of the particle swarm optimization algorithm for phase diversity.

Science.gov (United States)

Qi, Xin; Ju, Guohao; Xu, Shuyan

2018-04-10

The phase diversity (PD) technique needs optimization algorithms to minimize the error metric and find the global minimum. Particle swarm optimization (PSO) is very suitable for PD due to its simple structure, fast convergence, and global searching ability. However, the traditional PSO algorithm for PD still suffers from the stagnation problem (premature convergence), which can result in a wrong solution. In this paper, the stagnation problem of the traditional PSO algorithm for PD is illustrated first. Then, an explicit strategy is proposed to solve this problem, based on an in-depth understanding of the inherent optimization mechanism of the PSO algorithm. Specifically, a criterion is proposed to detect premature convergence; then a redistributing mechanism is proposed to prevent premature convergence. To improve the efficiency of this redistributing mechanism, randomized Halton sequences are further introduced to ensure the uniform distribution and randomness of the redistributed particles in the search space. Simulation results show that this strategy can effectively solve the stagnation problem of the PSO algorithm for PD, especially for large-scale and high-dimension wavefront sensing and noisy conditions. This work is further verified by an experiment. This work can improve the robustness and performance of PD wavefront sensing.

Effects of Gyejibongnyeong-hwan on dysmenorrhea caused by blood stagnation: study protocol for a randomized controlled trial

Directory of Open Access Journals (Sweden)

Park Jeong-Su

2012-01-01

Full Text Available Abstract Background Gyejibongnyeong-hwan (GJBNH is one of the most popular Korean medicine formulas for menstrual pain of dysmenorrhea. The concept of blood stagnation in Korean medicine is considered the main factor of causing abdominal pain, or cramps, during menstrual periods. To treat the symptoms, GJBNH is used to fluidify the stagnated blood and induce the blood flow to be smooth, reducing pain as the result. The purpose of this trial is to identify the efficacy of GJBNH in dysmenorrhea caused by blood stagnation. Methods This study is a multi-centre, randomised, double-blind, controlled trial with two parallel arms: the group taking GJBNH and the group taking placebo. 100 patients (women from age 18 to 35 will be enrolled to the trial. Through randomization 50 patients will be in experiment arm, and the other 50 patients will be in control arm. At the second visit (baseline, all participants who were already screened that they fulfil both the inclusion and the exclusion criteria will be randomised into two groups. Each group will take the intervention three times per day during two menstrual cycles. After the treatment for two cycles, each patient will be followed up during their 3rd, 4th and 5th menstrual cycles. From the screening (Visit 1 through the second follow-up (Visit 6 the entire process will take 25 weeks. Discussion This trial will provide evidence for the effectiveness of GJBNH in treating periodical pain due to dysmenorrhea that is caused by blood stagnation. The primary outcome between the two groups will be measured by changes in the Visual Analogue Score (VAS of pain. The secondary outcome will be measured by the Blood Stagnation Scale, the Short-form McGill questionnaire and the COX menstrual symptom scale. Analysis of covariance (ANCOVA and repeated measured ANOVA will be used to analyze the data analysis. Trial registration Current Controlled Trials: ISRCTN30426947

Constraining the timescale of magma stagnation beneath Mauna Kea volcano, Hawaii,using diffusion profiles in olivine phenocrysts

Science.gov (United States)

Bloch, E. M.; Ganguly, J.

2009-12-01

Fe-Mg diffusion profiles have been measured in olivine xenocrysts within alkalic basalts in order to constrain the timescales of magma stagnation beneath Mauna Kea volcano, Hawaii. It has been suggested that during the main tholeiitic shield-building stage, and postshield eruptive stages of Mauna Kea, magmas were stalled and stagnated near the Moho, at a depth of ~15 km. Evidence in support of this hypothesis comes from cumulates formed by gravity-settling and in situ crystallization within magma chambers (Fodor and Galar, 1997), and from clinopyroxene-wholerock thermobarometry on Hamakua basalts (Putirka, in press). The cumulates represent a ‘fossil’ magma chamber which formed primarily from tholeiitic basalts; during the later capping-lava stage of Mauna Kea, alkalic basalts tore off chunks of these cumulates during ascent to the surface. We have measured several diffusion profiles in olivine xenocrysts from a single basalt sample. Because these xenocrysts have homogenous core compositions identical to a neighboring dunite cumulate, and because they are much larger and texturally distinct from compositionally dissimilar olivine phenocrysts, they are interpreted to be cumulate olivines which were dislodged during magma recharge/mixing in the stagnation zone. Although the orientations of the phenocrysts are not yet known, the diffusion profiles have been fit using diffusion coefficients parallel to the c and a crystallographic axes (i.e. minimum and maximum values). Modeling diffusion profiles yields ∫Ddt ≤4.5 x 10-5 cm2. Assuming that the xenocrysts were broken off from the cumulate immediately when the magma chamber was recharged, it is possible to calculate the maximum stagnation time of the basalts. Thus, the retrieved ∫Ddt value yields a maximum stagnation time of ~0.7 years. References: Fodor RV, Galar, PA (1997). A View into the Subsurface of Mauna Kea Volcano, Hawaii: Crystallization Processes Interpreted through the Petrology and Petrography of

Possible Origin of Stagnation and Variability of Earth's Biodiversity

Science.gov (United States)

Stollmeier, Frank; Geisel, Theo; Nagler, Jan

2014-06-01

The magnitude and variability of Earth's biodiversity have puzzled scientists ever since paleontologic fossil databases became available. We identify and study a model of interdependent species where both endogenous and exogenous impacts determine the nonstationary extinction dynamics. The framework provides an explanation for the qualitative difference of marine and continental biodiversity growth. In particular, the stagnation of marine biodiversity may result from a global transition from an imbalanced to a balanced state of the species dependency network. The predictions of our framework are in agreement with paleontologic databases.

[Expressions of neurotransmitters in patients of insomnia differentiated as liver stagnation transforming into fire treated with acupuncture].

Science.gov (United States)

Ji, Xiangdong; Wang, Qunsong; Zhu, Wenxian

2015-06-01

To compare the difference in the efficacy between acupuncture and oral administration of trazodone and the expressions of neurotransmitters in patients of insomnia differentiated as liver stagnation transforming into fire. Seventy patients of insomnia differentiated as liver stagnation transforming into fire were randomized into an observation group and a control group, 35 cases in each one. In the observation group, acupuncture therapy was adopted at Shenmen (HT 7), Baihui (GV 20), Yintang (GV 29), Hegu (LI 4), Taichong (LR 3), etc. The needles were retained for 20 min each time. The treatment was given once a day, the treatment of 2 weeks made one session. In the control group, trazodone, 100 mg, oral administration, once a day, the treatment of 2 weeks made one session. Two sessions were required in the two groups. The scores in Pittsburgh sleep quality index (PSQI) and Asberg rating scale for side effects (SERS), the levels of neurotransmitters such as 5-hydroxy tryptamine (5-HT) and norepinephrine (NE) and the expressions of protein kinase C (PKC) and brain-derived neurotrophic factor (BDNF) in peripheral blood were observed before and after treatment in the two groups. PSQI score and SERS score after treatment were all decreased compared with those in both groups before treatment (both Pinsomnia differentiated as liver stagnation transforming into fire, and reduces serum NE level and increases 5-HT content and BDNF expression, which achieves the better efficacy as compared with the oral administration of trazodone. It is one of the effective approaches to the treatment of insomnia differentiated as liver stagnation transforming into fire.

Study of atmospheric stagnation, recirculation, and ventilation potential at Narora Atomic Power Station site

International Nuclear Information System (INIS)

Kumar, Deepak; Kumar, Avinash; Kumar, Vimal; Rao, K.S.; Kumar, Jaivender; Ravi, P.M.

2011-01-01

Atmosphere is an important pathway to be considered in assessment of the environmental impact of radioactivity releases from nuclear facilities. Estimation of concentration of released effluents in air and possible ground contamination needs an understanding of relevant atmospheric dispersion. This article describes the meteorological characteristics of Narora Atomic Power Station (NAPS) site by using the integral parameters developed by Allwine and Whiteman. Meteorological data measured during the period 2006-2010 were analyzed. The integral quantities related to the occurrence of stagnation, recirculation, and ventilation characteristics were studied for NAPS site to assess the dilution potential of the atmosphere. Wind run and recirculation factors were calculated for a 24-h transport time using 5 years of hourly surface measurements of wind speed and direction. The occurrence of stagnation, recirculation, and ventilation characteristics during 2006-2010 at NAPS site is observed to be 33.8% of the time, 19.5% of the time, and 34.7% of the time, respectively. The presence of strong winds with predominant wind direction NW and WNW during winter and summer seasons leads to higher ventilation (48.1% and 44.3%) and recirculation (32.6% of the summer season). The presence of light winds and more dispersed winds during prewinter season with predominant wind directions W and WNW results in more stagnation (59.7% of the prewinter season). Thus, this study will serve as an essential meteorological tool to understand the transport mechanism of atmospheric radioactive effluent releases from any nuclear industry. (author)

Void fraction distribution in a heated rod bundle under flow stagnation conditions

Energy Technology Data Exchange (ETDEWEB)

Herrero, V.A.; Guido-Lavalle, G.; Clausse, A. [Centro Atomico Bariloche and Instituto Balseiro, Bariloche (Argentina)

1995-09-01

An experimental study was performed to determine the axial void fraction distribution along a heated rod bundle under flow stagnation conditions. The development of the flow pattern was investigated for different heat flow rates. It was found that in general the void fraction is overestimated by the Zuber & Findlay model while the Chexal-Lellouche correlation produces a better prediction.

An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system.

Science.gov (United States)

Zlatanović, Lj; van der Hoek, J P; Vreeburg, J H G

2017-10-15

The drinking water quality changes during the transport through distribution systems. Domestic drinking water systems (DDWSs), which include the plumbing between the water meter and consumer's taps, are the most critical points in which water quality may be affected. In distribution networks, the drinking water temperature and water residence time are regarded as indicators of the drinking water quality. This paper describes an experimental research on the influence of stagnation time and temperature change on drinking water quality in a full-scale DDWS. Two sets of stagnation experiments, during winter and summer months, with various stagnation intervals (up to 168 h of stagnation) were carried out. Water and biofilms were sampled at two different taps, a kitchen and a shower tap. Results from this study indicate that temperature and water stagnation affect both chemical and microbial quality in DDWSs, whereas microbial parameters in stagnant water appear to be driven by the temperature of fresh water. Biofilm formed in the shower pipe contained more total and intact cells than the kitchen pipe biofilm. Alphaproteobacteria were found to dominate in the shower biofilm (78% of all Proteobacteria), while in the kitchen tap biofilm Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were evenly distributed. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

MEDIATOR18 and MEDIATOR20 confer susceptibility to Fusarium oxysporum in Arabidopsis thaliana

OpenAIRE

Fallath, Thorya; Kidd, Brendan N.; Stiller, Jiri; Davoine, Celine; Bj?rklund, Stefan; Manners, John M.; Kazan, Kemal; Schenk, Peer M.

2017-01-01

The conserved protein complex known as Mediator conveys transcriptional signals by acting as an intermediary between transcription factors and RNA polymerase II. As a result, Mediator subunits play multiple roles in regulating developmental as well as abiotic and biotic stress pathways. In this report we identify the head domain subunits MEDIATOR18 and MEDIATOR20 as important susceptibility factors for Fusarium oxysporum infection in Arabidopsis thaliana. Mutants of MED18 and MED20 display do...

Climatic and technological ceilings for Chinese rice stagnation based on yield gaps and yield trend pattern analysis.

Science.gov (United States)

Zhang, Tianyi; Yang, Xiaoguang; Wang, Hesong; Li, Yong; Ye, Qing

2014-04-01

Climatic or technological ceilings could cause yield stagnation. Thus, identifying the principal reasons for yield stagnation within the context of the local climate and socio-economic conditions are essential for informing regional agricultural policies. In this study, we identified the climatic and technological ceilings for seven rice-production regions in China based on yield gaps and on a yield trend pattern analysis for the period 1980-2010. The results indicate that 54.9% of the counties sampled experienced yield stagnation since the 1980. The potential yield ceilings in northern and eastern China decreased to a greater extent than in other regions due to the accompanying climate effects of increases in temperature and decreases in radiation. This may be associated with yield stagnation and halt occurring in approximately 49.8-57.0% of the sampled counties in these areas. South-western China exhibited a promising scope for yield improvement, showing the greatest yield gap (30.6%), whereas the yields were stagnant in 58.4% of the sampled counties. This finding suggests that efforts to overcome the technological ceiling must be given priority so that the available exploitable yield gap can be achieved. North-eastern China, however, represents a noteworthy exception. In the north-central area of this region, climate change has increased the yield potential ceiling, and this increase has been accompanied by the most rapid increase in actual yield: 1.02 ton ha(-1) per decade. Therefore, north-eastern China shows a great potential for rice production, which is favoured by the current climate conditions and available technology level. Additional environmentally friendly economic incentives might be considered in this region. © 2013 John Wiley & Sons Ltd.

Institutionel stagnation i hertugdømmet Slesvig 1840-1860

DEFF Research Database (Denmark)

Clausen, Thomas

2017-01-01

This article provides a study of the framework conditions for trade and industry in the Duchy of Schleswig in the middle of the 19th century. Grounded on theory of institutional economics the main argument of the paper is that Schleswig on a range of parameters suffered from stagnation...... in the development of the economy. The cause of this slowdown had to do with inertia in adaption of important institutional arrangement to the increasing complexity of trade and business. The study concludes that the Duchy, despite a seemingly favorable starting point, lost ground and that the institutional...

Effects of platinum stagnation surface on the lean extinction limits of premixed methane/air flames at moderate surface temperatures

Energy Technology Data Exchange (ETDEWEB)

Wiswall, J.T.; Li, J.; Wooldridge, M.S.; Im, H.G. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI (United States)

2011-01-15

A stagnation flow reactor was used to study the effects of platinum on the lean flammability limits of atmospheric pressure premixed methane/air flames at moderate stagnation surface temperatures. Experimental and computational methods were used to quantify the equivalence ratio at the lean extinction limit ({phi}{sub ext}) and the corresponding stagnation surface temperature (T{sub s}). A range of flow rates (57-90 cm/s) and corresponding strain rates were considered. The results indicate that the gas-phase methane/air flames are sufficiently strong relative to the heterogeneous chemistry for T{sub s} conditions less than 750 K that the platinum does not affect {phi}{sub ext}. The computational results are in good agreement with the experimentally observed trends and further indicate that higher reactant flow rates (>139 cm/s) and levels of dilution (>{proportional_to}10% N{sub 2}) are required to weaken the gas-phase flame sufficiently for surface reaction to play a positive role on extending the lean flammability limits. (author)

Detection of flow separation and stagnation points using artificial hair sensors

International Nuclear Information System (INIS)

Phillips, D M; Baur, J W; Ray, C W; Hagen, B J; Reich, G W; Su, W

2015-01-01

Recent interest in fly-by-feel approaches for aircraft control has motivated the development of novel sensors for use in aerial systems. Artificial hair sensors (AHSs) are one type of device that promise to fill a unique niche in the sensory suite for aerial systems. In this work, we investigate the capability of an AHS based on structural glass fibers to directly identify flow stagnation and separation points on a cylindrical domain in a steady flow. The glass fibers are functionalized with a radially aligned carbon nanotube (CNT) forest and elicit a piezoresistive response as the CNT forest impinges on electrodes in a micropore when the hair is deflected due to viscous drag forces. Particle image velocimetry is used to measure the flow field allowing for the resulting moment and force acting on the hair to be correlated with the electrical response. It is demonstrated that the AHS provides estimates for the locations of both the stagnation and separation in steady flow. From this, a simulation of a heading estimation is presented to demonstrate a potential application for hair sensors. These results motivate the construction of large arrays of hair sensors for imaging and resolving flow structures in real time. (paper)

Using 1D theory to understand 3D stagnation of a wire-array Z pinch in the absence of radiation

Science.gov (United States)

Yu, Edmund

2015-11-01

Many high-energy-density systems implode towards the axis of symmetry, where it collides on itself, forming a hot plasma. However, experiments show these imploding plasmas develop three-dimensional (3D) structures. As a result, the plasma cannot completely dissipate its kinetic energy at stagnation, instead retaining significant 3D flow. A useful tool for understanding the effects of this residual flow is 3D simulation, but the amount and complexity of information can be daunting. To address this problem, we explore the connection between 3D simulation and one-dimensional (1D) theory. Such a connection, if it exists, is mutually beneficial: 1D theory can provide a clear picture of the underlying dynamics of 3D stagnation. On the other hand, deviations between theory and simulation suggest how 1D theory must be modified to account for 3D effects. In this work, we focus on a 3D, magnetohydrodynamic simulation of a compact wire-array Z pinch. To provide a simpler background against which to test our ideas, we artificially turn off radiation during the stagnation phase. Examination of the initial accumulation of mass on axis reveals oblique collision between jets, shock accretion, and vortex formation. Despite evidence for shock-dominated stagnation, a 1D shockless stagnation solution is more appropriate for describing the global dynamics, in that it reproduces the increase of on-axis density with time. However, the 1D solution must be modified to account for 3D effects: the flows suggest enhanced thermal transport as well as centrifugal force. Upon reaching peak compression, the stagnation transitions to a second phase, in which the high-pressure core on axis expands outward into the remaining imploding plasma. During this phase, a 1D shock solution describes the growth of the shock accretion region, as well as the decrease of on-axis density with time. However, the effect of 3D flows is still present: the on-axis temperature does not cool during expansion, which

Peer-Mediated AAC Instruction for Young Children with Autism and other Developmental Disabilities.

Science.gov (United States)

Thiemann-Bourque, Kathy

2012-12-01

Many young children with developmental disabilities (DD) have significant delays in social, communication, and play skills. For those children learning to use augmentative and alternative communication (.AAC% successful social interactions with peers will require explicit instruction on the same system for both communication partners. Peer-mediated (PM) interventions are recommended best practice based on more than 30 years of research with young children with autism and other DDs. Integrating direct AAC instruction within PM programs to advance social reciprocity in typical preschool routines is a necessary and important next step for young AAC users. In this article, I will summarize the design and outcomes of two PM AAC studies documenting positive social outcomes for preschool children with severe autism. I will also teach } peer partners how to use AAC highlight strategies to recruit peers without disabilities systems (e.g., Picture Exchange Communication System [PECS], Speech Generating Devices [SGDs]), and engineer the preschool classroom for successful AAC communication. I will describe data collection procedures for measuring changes in reciprocal child and peer social communication interactions.

Orality disorders in melancholia: acedia as stagnation

Directory of Open Access Journals (Sweden)

Ana Cecília Magtaz

2012-09-01

Full Text Available In this article valuable contributions by Lasègue, Freud and Abraham are discussed, as they are all indispensible to the understanding of orality disorders in melancholia. Although none of the above authors used the exact term "orality disorders," their understandings of both hysteria and melancholia are important in the debate surrounding the clinical treatment of these difficulties. Sadness is a common denominator for the authors, but contributions on acedia, the "noonday demon" mentioned by Agamben, are also important. Acedia is defined as stagnation, a desperate lack of vigor when faced with a wearying and demanding situation. Those who suffer from chronic acedia feel great inertia and are unable to envision a future. They see their creativity wane away, especially due to the painful isolation caused by what might be called anguished sadness - a denial of sadness through manic action.

Pressure and temperature development in solar heating system during stagnation

DEFF Research Database (Denmark)

Dragsted, Janne; Furbo, Simon; Chen, Ziqian

2010-01-01

of the pipes of the solar collector loop. During the investigation the pre-pressure of the expansion vessel and system filling pressure was changed. The investigations showed that a large pressurised expansion vessel will protect the collector loop from critically high temperatures as long as the solar......This paper presents an investigation of stagnation in solar collectors and the effects it will have on the collector loop. At a laboratory test stand at the Technical University of Denmark, a pressurized solar collector loop was designed to test different numbers of collectors and different designs...

Dynamic and Stagnating Plasma Flow Leading to Magnetic-Flux-Tube Collimation

International Nuclear Information System (INIS)

You, S.; Yun, G.S.; Bellan, P.M.

2005-01-01

Highly collimated, plasma-filled magnetic-flux tubes are frequently observed on galactic, stellar, and laboratory scales. We propose that a single, universal magnetohydrodynamic pumping process explains why such collimated, plasma-filled magnetic-flux tubes are ubiquitous. Experimental evidence from carefully diagnosed laboratory simulations of astrophysical jets confirms this assertion and is reported here. The magnetohydrodynamic process pumps plasma into a magnetic-flux tube and the stagnation of the resulting flow causes this flux tube to become collimated

Impeding hohlraum plasma stagnation in inertial-confinement fusion.

Science.gov (United States)

Li, C K; Séguin, F H; Frenje, J A; Rosenberg, M J; Rinderknecht, H G; Zylstra, A B; Petrasso, R D; Amendt, P A; Landen, O L; Mackinnon, A J; Town, R P J; Wilks, S C; Betti, R; Meyerhofer, D D; Soures, J M; Hund, J; Kilkenny, J D; Nikroo, A

2012-01-13

This Letter reports the first time-gated proton radiography of the spatial structure and temporal evolution of how the fill gas compresses the wall blowoff, inhibits plasma jet formation, and impedes plasma stagnation in the hohlraum interior. The potential roles of spontaneously generated electric and magnetic fields in the hohlraum dynamics and capsule implosion are discussed. It is shown that interpenetration of the two materials could result from the classical Rayleigh-Taylor instability occurring as the lighter, decelerating ionized fill gas pushes against the heavier, expanding gold wall blowoff. This experiment showed new observations of the effects of the fill gas on x-ray driven implosions, and an improved understanding of these results could impact the ongoing ignition experiments at the National Ignition Facility.

The stagnation of the Mexican male life expectancy in the first decade of the 21st century

DEFF Research Database (Denmark)

Canudas-Romo, Vladimir; García-Guerrero, Víctor Manuel; Echarri-Cánovas, Carlos Javier

2015-01-01

OBJECTIVES: In the first decade of the 21st century, the Mexican life expectancy changed from a long trend of increase to stagnation. These changes concur with an increase in deaths by homicides that the country experienced in that decade, and an obesity epidemic that had developed over the last...... of life expectancy from 2000 to 2010. RESULTS: The apparent stagnation in life expectancy is the result of an increase in deaths by homicides and diabetes mellitus on the one hand, and the positive improvements observed in other causes of death on the other. The negative impact of homicides...... by 2 years if deaths by homicides and diabetes mellitus had been avoided....

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

International Nuclear Information System (INIS)

Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D.

2015-01-01

Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch ICN-TG ). Following exposure of adult Notch ICN-TG mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch ICN-TG offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch ICN-TG offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch-induced thymoma was different in

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

Energy Technology Data Exchange (ETDEWEB)

Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D., E-mail: laiosa@uwm.edu

2015-03-01

Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch

A novel ecdysone receptor mediates steroid-regulated developmental events during the mid-third instar of Drosophila.

Directory of Open Access Journals (Sweden)

Benjamin F B Costantino

2008-06-01

Full Text Available The larval salivary gland of Drosophila melanogaster synthesizes and secretes glue glycoproteins that cement developing animals to a solid surface during metamorphosis. The steroid hormone 20-hydroxyecdysone (20E is an essential signaling molecule that modulates most of the physiological functions of the larval gland. At the end of larval development, it is known that 20E--signaling through a nuclear receptor heterodimer consisting of EcR and USP--induces the early and late puffing cascade of the polytene chromosomes and causes the exocytosis of stored glue granules into the lumen of the gland. It has also been reported that an earlier pulse of hormone induces the temporally and spatially specific transcriptional activation of the glue genes; however, the receptor responsible for triggering this response has not been characterized. Here we show that the coordinated expression of the glue genes midway through the third instar is mediated by 20E acting to induce genes of the Broad Complex (BRC through a receptor that is not an EcR/USP heterodimer. This result is novel because it demonstrates for the first time that at least some 20E-mediated, mid-larval, developmental responses are controlled by an uncharacterized receptor that does not contain an RXR-like component.

Studies on scaling of flow noise received at the stagnation point of an axisymmetric body

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Arakeri, V. H.; Satyanarayana, S. G.; Mani, K.; Sharma, S. D.

1991-05-01

A description of the studies related to the problem of scaling of flow noise received at the stagnation point of axisymmetric bodies is provided. The source of flow noise under consideration is the transitional/turbulent regions of the boundary layer flow on the axisymmetric body. Lauchle has recently shown that the noise measured in the laminar region (including the stagnation point) corresponds closely to the noise measured in the transition region, provided that the acoustic losses due to diffraction are accounted for. The present study includes experimental measurement of flow noise at the stagnation point of three different shaped axisymmetric headforms. One of the body shapes chosen is that used by Lauchle in similar studies. This was done to establish the effect of body size on flow noise. The results of the experimental investigations clearly show that the flow noise received at the stagnation point is a strong function of free stream velocity, a moderately strong function of body scale but a weak function of boundary layer thickness. In addition, there is evidence that when body scale change is involved, flow noise amplitude scales but no frequency shift is involved. A scaling procedure is proposed based on the present observations along with those of Lauchle. At a given frequency, the amplitude of noise level obtained under model testing conditions is first scaled to account for differences in the velocity and size corresponding to the prototype conditions; then a correction to this is applied to account for losses due to diffraction, which are estimated on the basis of the geometric theory of diffraction (GTD) with the source being located at the predicted position of turbulent transition. Use of the proposed scaling law to extrapolate presently obtained noise levels to two other conditions involving larger-scale bodies show good agreement with actually measured levels, in particular at higher frequencies. Since model scale results have been used

On two special values of temperature factor in hypersonic flow stagnation point

Science.gov (United States)

Bilchenko, G. G.; Bilchenko, N. G.

2018-03-01

The hypersonic aircraft permeable cylindrical and spherical surfaces laminar boundary layer heat and mass transfer control mathematical model properties are investigated. The nonlinear algebraic equations systems are obtained for two special values of temperature factor in the hypersonic flow stagnation point. The mappings bijectivity between heat and mass transfer local parameters and controls is established. The computation experiments results are presented: the domains of allowed values “heat-friction” are obtained.

Health-related quality of life in fathers of children with or without developmental disability: the mediating effect of parental stress.

Science.gov (United States)

Huang, Yu-Ping; Chang, Ming-yuh; Chi, Yu-Lin; Lai, Fei-Chen

2014-02-01

The aims of this study were to compare parental stress and health-related quality of life (HRQOL) between Taiwanese fathers of children with and without developmental disabilities (DDs) and to examine the mediating effect of parental stress on the association between having a child with DD and paternal HRQOL within Chinese culture. This cross-sectional, prospective, unmatched case-control study included 206 fathers of children with DDs and 207 fathers of healthy children. HRQOL was assessed by the SF-36 short-form questionnaire, and parental stress was assessed by the Chinese version Parental Stress Scale. Fathers of children with DDs experienced poorer mental and physical HRQOL and higher parental stress than fathers of healthy children. Parental stress acted as a complete mediator for paternal physical HRQOL, while parental stress had a partial mediating effect on the relationship between having a child with DD and paternal mental HRQOL. Having a child with DD also directly affected paternal mental HRQOL. Fathers of children with DDs should be monitored for parental stress and HRQOL, and interventions should be provided to empower them with the knowledge and skills to reduce their stress and to enhance their HRQOL.

Stagnating energy efficiency in the Swedish building sector-Economic and organisational explanations

International Nuclear Information System (INIS)

Naessen, Jonas; Sprei, Frances; Holmberg, John

2008-01-01

The development towards higher energy efficiency in the Swedish building sector stagnated in the late 1980s and 1990s. In new buildings the average specific energy use for heating is twice as high as in the best performing buildings 20 years ago. By combining econometric studies and interviews with actors in the building sector we analyse the underlying economic and organisational causes for this development. In the stock of buildings, specific energy use for heating (kWh/m 2 /yr) has a high correlation with increasing energy prices and price elasticities have not changed markedly over time. This implies that the stagnation to a large extent can be explained by energy price trends. On the contrary, in new buildings the correlation between energy prices and specific energy use is much weaker. One important cause of low sensitivity to price changes is that information about the life cycle cost (LCC) of different investment alternatives is often not available to the involved actors. The most common investment criterion is instead the requirements of the national building energy standard which has developed into a norm rather than a minimum for energy performance. In this paper we also discuss potential improvements in the learning processes within the sector

International health policy and stagnating maternal mortality: is there a causal link?

Science.gov (United States)

Unger, Jean-Pierre; Van Dessel, Patrick; Sen, Kasturi; De Paepe, Pierre

2009-05-01

This paper examines why progress towards Millennium Development Goal 5 on maternal health appears to have stagnated in much of the global south. We contend that besides the widely recognised existence of weak health systems, including weak services, low staffing levels, managerial weaknesses, and lack of infrastructure and information, this stagnation relates to the inability of most countries to meet two essential conditions: to develop access to publicly funded, comprehensive health care, and to provide the not-for-profit sector with needed political, technical and financial support. This paper offers a critical perspective on the past 15 years of international health policies as a possible cofactor of high maternal mortality, because of their emphasis on disease control in public health services at the expense of access to comprehensive health care, and failures of contracting out and public-private partnerships in health care. Health care delivery cannot be an issue both of trade and of right. Without policies to make health systems in the global south more publicly-oriented and accountable, the current standards of maternal and child health care are likely to remain poor, and maternal deaths will continue to affect women and their families at an intolerably high level.

Unsteady MHD stagnation flow over a moving wall

International Nuclear Information System (INIS)

Kumari, M.; Nath, G.

2006-01-01

The unsteady viscous stagnation flow of an electrically conducting fluid over a continuously moving wall with an applied magnetic field has been investigated when the free stream and wall velocities increase arbitrarily with time. The flow is initially (t = 0) steady and at time t > 0, it becomes unsteady. The semi-similar solution of the unsteady Navier-Stokes equations along with the energy equation governing the flow and heat transfer has been obtained numerically. Also the self-similar solution is obtained when the surface and free stream velocities vary inversely as a linear function of time. The shear stress and the heat transfer increase with time and magnetic field. The surface shear stress vanishes for certain value of the ratio of the wall velocity to the free stream velocity. (author)

Recirculation, stagnation and ventilation: The 2014 legionella episode

Science.gov (United States)

Russo, Ana; Soares, Pedro M. M.; Gouveia, Célia M.; Cardoso, Rita M.; Trigo, Ricardo M.

2017-04-01

Legionella transmission through the atmosphere is unusual, but not unprecedented. A scientific paper published in 2006 reports a surge in Pas-de-Calais, France, in which 86 people have been infected by bacteria released by a cooling tower more than 6 km away [3]. Similarly, in Norway, in 2005, there was another case where contamination spread beyond 10 km, although more concentrated within a radius of 1 km from an industrial unit [2]. An unprecedented large Legionella outbreak occurred in November 2014 nearby Lisbon, Portugal. As of 7 November 2014, 375 individuals become hill and 12 died infected by the Legionella pneumophila bacteria, contracted by inhalation of steam droplets of contaminated water (aerosols). These droplets are so small that can carry the bacteria directly to the lungs, depositing it in the alveoli. One way of studying the propagation of legionella episodes is through the use of aerosol dispersion models. However, such approaches often require detailed 3D high resolution wind data over the region, which isn't often available for long periods. The likely impact of wind on legionella transmission can also be understood based on the analysis of special types of flow conditions such as stagnation, recirculation and ventilation [1, 4]. The Allwine and Whiteman (AW) approach constitutes a straightforward method to assess the assimilative and dispersal capacities of different airsheds [1,4], as it only requires hourly wind components. Thus, it has the advantage of not needing surface and upper air meteorological observations and a previous knowledge of the atmospheric transport and dispersion conditions. The objective of this study is to analyze if the legionella outbreak event which took place in November 2014 had extreme potential recirculation and/or stagnation characteristics. In order to accomplish the proposed objective, the AW approach was applied for a hindcast time-series covering the affected area (1989-2007) and then for an independent

Avoiding Intellectual Stagnation: The Starship as an Expander of Minds

Science.gov (United States)

Crawford, Ian A.

2014-06-01

Interstellar exploration will advance human knowledge and culture in multiple ways. Scientifically, it will advance our understanding of the interstellar medium, stellar astrophysics, planetary science and astrobiology. In addition, significant societal and cultural benefits will result from a programme of interstellar exploration and colonisation. Most important will be the cultural stimuli resulting from expanding the horizons of human experience, and increased opportunities for the spread and diversification of life and culture through the Galaxy. Ultimately, a programme of interstellar exploration may be the only way for human (and post-human) societies to avoid the intellectual stagnation predicted for the `end of history'.

Locus of control fails to mediate between stress and anxiety and depression in parents of children with a developmental disorder.

Science.gov (United States)

Hamlyn-Wright, Sarah; Draghi-Lorenz, Riccardo; Ellis, Jason

2007-11-01

Stress, anxiety and depression are raised amongst parents of children with a developmental disorder. However, the processes by which stress leads to depression and anxiety are poorly understood. In a cross-sectional survey, levels of parental stress, depression and anxiety were compared between parents of children with an autistic disorder, children with Down's syndrome and children with no disorder (N = 619) and the mediational role of locus of control was examined. Anxiety and depression were higher in parents of children with a disorder, and highest in parents of children with autism. Locus of control was more external in parents of children with autism. Locus of control failed to mediate the relationship between stress and both anxiety and depression in parents of children with a disorder. This suggests that help for parents of a child with a disorder may be effective if focused on the sources of stress rather than perceived control over events.

Developmental trajectories and longitudinal mediation effects of self-esteem, peer attachment, child maltreatment and depression on early adolescents.

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Ju, Soyoung; Lee, Yanghee

2018-02-01

The purpose of this study is to identify the developmental trajectories of peer attachment, self-esteem, depression, and child maltreatment, and to understand the longitudinal mediation effects that peer attachment and self-esteem have on the influence of perceived abuse on early adolescent depression. This study uses Year 1 to Year 5 data of the 4th grader panel of the Korea Youth Panel Survey (KYPS) and utilizes a multivariate latent growth model to analyze the main variables in the applicable data between 5th (i.e., Year 2) and 8th (i.e., Year 5) grades. The results indicate that from the 5th to the 8th grade, the degree of abuse and depression increases while self-esteem gradually decreases with slowly lowering peer attachment. A significant distribution of the initial values and the rate of change were present for all main variables of the study, confirming individual differences in time wise changes. Further, more exposure to abuse correlated with a decrease in self-esteem, while an increase in self-esteem greatly reduced depression. The initial value of self-esteem showed a partial mediation effect, whereas the rate of change indicated a full mediation effect with a significant longitudinal mediation effect. More experience of abuse during early adolescence indicated a lower degree of peer attachment, and a higher peer attachment was related to decreased depression. A significant partial mediation effect was present for both the initial value and the rate of change of peer attachment, and a longitudinal mediation effect was present. This study confirmed that self-esteem in early adolescents is an important protective factor that can greatly reduce the degree of depression, and suggests continuous interventions conducted to increase self-esteem in adolescence. Furthermore, by determining that peer attachment decreases the degree of depression in children at risk, the study emphasizes the healing aspect of adolescent peer attachment. Copyright © 2017 Elsevier

Numerical modeling of time-dependent bio-convective stagnation flow of a nanofluid in slip regime

Directory of Open Access Journals (Sweden)

Rakesh Kumar

Full Text Available A numerical investigation of unsteady stagnation point flow of bioconvective nanofluid due to an exponential deforming surface is made in this research. The effects of Brownian diffusion, thermophoresis, slip velocity and thermal jump are incorporated in the nanofluid model. By utilizing similarity transformations, the highly nonlinear partial differential equations governing present nano-bioconvective boundary layer phenomenon are reduced into ordinary differential system. The resultant expressions are solved for numerical solution by employing a well-known implicit finite difference approach termed as Keller-box method (KBM. The influence of involved parameters (unsteadiness, bioconvection Schmidt number, velocity slip, thermal jump, thermophoresis, Schmidt number, Brownian motion, bioconvection Peclet number on the distributions of velocity, temperature, nanoparticle and motile microorganisms concentrations, the coefficient of local skin-friction, rate of heat transport, Sherwood number and local density motile microorganisms are exhibited through graphs and tables. Keywords: Unsteadiness, Bio-convection, Slip regime, Stagnation point flow, Numerical modeling

Stagnation-point flow of second grade nanofluid towards a nonlinear stretching surface with variable thickness

Directory of Open Access Journals (Sweden)

Rai Sajjad Saif

Full Text Available This paper investigates the stagnation point flow of second grade nanomaterial towards a nonlinear stretching surface subject to variable surface thickness. The process of heat transfer is examined through the melting heat and mixed convection effects. Further novel features regarding Brownian motion and thermophoresis are present. Boundary-layer approximation is employed in the problem formulation. Momentum, energy and concentration equations are converted into the non-linear ordinary differential system through the appropriate transformations. Convergent solutions for resulting problem are computed. Behaviors of various sundry variables on temperature and concentration are studied in detail. The skin friction coefficient and heat and mass transfer rates are also computed and analyzed. Our results indicate that the temperature and concentration distributions are enhanced for larger values of thermophoresis parameter. Further the present work is hoped to be useful in improving the performance of heat transfer of base fluid. Keywords: Stagnation-point flow, Second grade fluid, Nanoparticles, Melting heat process, Nonlinear stretching surface, Variable surface thickness

Stagnation of the exploitation of Al ores and the depression of world prices of Al

Directory of Open Access Journals (Sweden)

Slavkovský Jozef

1999-03-01

Full Text Available In the contribution, data on Al – a metal of the 20th century are compiled together with the problems of genesis of the Al mineral raw ma-terials as well as types of bauxite and Al-laterite deposits. Furthermore, an overview of the world exploitation of bauxite during 1935-1980 is given along with the prognoses to 2000 and present situation (1992-1996. Overviews of the production of Al follows, providing its rela-tion to the bauxite exploitation. Contrary to the prognoses, a stabilization or stagnation has been observed in the exploitation of bauxite and production of Al during nineties, which a tendency is directly reflected in the world price of this commodity. When analyzing the Al prices for a longer period, some serious deviations can be noticed, that however presently represent a long-term minimum. We hope the stagnation of the production and the price decline are only temporary and new possibilities of the utilization of Al will be found soon.

Impacts of Anthropogenic Aerosols on Regional Climate: Extreme Events, Stagnation, and the United States Warming Hole

Science.gov (United States)

Mascioli, Nora R.

temperature response pattern in AER and GHG is characterized by strong responses over the western U.S. and weak or opposite signed responses over the southeast U.S., raising the question of whether the observed U.S. "warming hole" could have a forced component. To address this question, I systematically examine observed seasonal temperature trends over all time periods of at least 10 years during 1901-2015. In the northeast and southern U.S., significant summertime cooling occurs from the early 1950s to the mid 1970s, which I partially attribute to increasing anthropogenic aerosol emissions (median fraction of the observed temperature trends explained is 0.69 and 0.17, respectively). In winter, the northeast and southern U.S. cool significantly from the early 1950s to the early 1990s, which I attribute to long-term phase changes in the North Atlantic Oscillation and the Pacific Decadal Oscillation. Rather than being a single phenomenon stemming from a single cause, both the warming hole and its dominant drivers vary by season, region, and time period. Finally, I examine historical and projected future changes in atmospheric stagnation. Stagnation, which is characterized by weak winds and an absence of precipitation, is a meteorological contributor to heat waves, extreme pollution, and drought. Using CM3, I show that regional stagnation trends over the historical period (1860-2005) are driven by changes in anthropogenic aerosol emissions, rather than rising greenhouse gases. In the northeastern and central United States, aerosol-induced changes in surface and upper level winds produce significant decreases in the number of stagnant summer days, while decreasing precipitation in the southeast US increases the number of stagnant summer days. Outside of the U.S., significant drying over eastern China in response to rising aerosol emissions contributed to increased stagnation during 1860-2005. Additionally, this region was found to be particularly sensitive to changes in local

Sealable stagnation flow geometries for the uniform deposition of materials and heat

Science.gov (United States)

McCarty, Kevin F.; Kee, Robert J.; Lutz, Andrew E.; Meeks, Ellen

2001-01-01

The present invention employs a constrained stagnation flow geometry apparatus to achieve the uniform deposition of materials or heat. The present invention maximizes uniform fluxes of reactant gases to flat surfaces while minimizing the use of reagents and finite dimension edge effects. This results, among other things, in large area continuous films that are uniform in thickness, composition and structure which is important in chemical vapor deposition processes such as would be used for the fabrication of semiconductors.

Where Do Epigenetics and Developmental Origins Take the Field of Developmental Psychopathology?

Science.gov (United States)

Nigg, Joel T

2016-04-01

The time is ripe for upgrading or rethinking the assumed paradigms for how we study developmental psychopathology. The classic transactional models appear robust but need specification in terms of biological and psychosocial processes. That specification is increasingly tractable due to developments in genetics, epigenetics, the measurement of psychosocial processes, and theory and data on developmental origins of health and disease. This essay offers a high-level view of where the field has been and where it may be going in regard to nosology and conceptions of etiology. Remarks seek to consider rapidly evolving contexts not only for children, but also for the science itself due to progress in our field and in neighboring fields. Illustrations are provided as to how syndromal nosology can be enriched and advanced by careful integration with biologically relevant behavioral dimensions and application of quantitative methods. It is concluded that a revised, forward-looking, transactional model of abnormal child psychology will incorporate prenatal and postnatal developmental programming, epigenetic mechanisms and their associated genotype x environment interactions, and inflammatory processes as a potential common mediator influencing numerous health and mental health conditions.

Developmental Risk and Young Children's Regulatory Strategies: Predicting Behavior Problems at Age Five

Science.gov (United States)

Gerstein, Emily D.; Pedersen y Arbona, Anita; Crnic, Keith A.; Ryu, Ehri; Baker, Bruce L.; Blacher, Jan

2011-01-01

Children with early developmental delays are at heightened risk for behavior problems and comorbid psychopathology. This study examined the trajectories of regulatory capabilities and their potentially mediating role in the development of behavior problems for children with and without early developmental delays. A sample of 231 children comprised…

Stagnations of increasing trends in negative pressure with repeated cavitation in water/metal Berthelot tubes as a result of mechanical sealing

International Nuclear Information System (INIS)

Hiro, Kazuki; Ohde, Yoshihito; Tanzawa, Yasutoshi

2003-01-01

To investigate effects of mechanical sealing on negative pressures in water/metal tube Berthelot systems, trends in negative pressure are observed through runs of temperature cycles below 90 deg. C in two systems made of metals having small amounts of gas inclusions. The first system is a pre-degassed all-stainless-steel tube/plug system. The steel is a special product for vacuum engineering. The second is the same tube sealed with plugs made of silver solidified one-dimensionally in a vacuum furnace. A new type of trend, stagnation for intermediate cycles is found in both systems so long as sealing distortion of each plug is small in amount. The stagnation period for the first system is longer than that for the second one. A metallurgical mechanism of a gas-being-replenished crevice model is proposed: distorted parts of metals undergo heat-treatment during runs of temperature cycles, and the heat-treatment enhances the rates of impurity gas transports to crevices on the metal surface where cavitation occurs, and the transport causes the stagnation for cycles during which the rates are still high

Relations of Early Motor Skills on Age and Socialization, Communication, and Daily Living in Young Children With Developmental Disabilities.

Science.gov (United States)

MacDonald, Megan; Ross, Samantha; McIntyre, Laura Lee; Tepfer, Amanda

2017-04-01

Young children with developmental disabilities experience known deficits in salient child behaviors, such as social behaviors, communication, and aspects of daily living, behaviors that generally improve with chronological age. The purpose of this study was to examine the mediating effects of motor skills on relations of age and salient child behaviors in a group of young children with developmental disabilities, thus tapping into the potential influences of motor skills in the development of salient child behaviors. One hundred thirteen young children with developmental disabilities participated in this study. Independent mediation analysis, with gender as a moderator between the mediating and outcome variable, indicated that motor skills meditated relations between age and socialization, communication, and daily living skills in young male children with developmental disabilities, but not female participants. Findings suggest motor skill content needs to be considered in combination with other child behaviors commonly focused on in early intervention.

Expansionary economic effects of energy conversion under stagnation

International Nuclear Information System (INIS)

Ono, Yoshiyasu

2013-01-01

After the Fukushima disaster, energy conversion such as nuclear power phaseout and deployment of renewable energy or survival of nuclear power had been actively argued pro and con. Both sides admitted extra costs were needed but their economic effects would be contrary dependent on business state. Under better economy, extra costs would be actual burden of total economy. Under stagnation as was long in Japan at present, extra costs brought about expansion of employment and economy with simulated consumption increase. Industry conversion would occur such industry intensively using power would depreciate and energy conserved industry would grow. Difference of power use intensity between industries made difficult in energy conversion because present Japanese industry constitution was mostly formed based on cheap power cost for industry use. Even taking account of international competition, the same would be true by adjusting finance balance sheet and currency exchange rate. (T. Tanaka)

Characteristics of buoyancy force on stagnation point flow with magneto-nanoparticles and zero mass flux condition

Directory of Open Access Journals (Sweden)

Iftikhar Uddin

2018-03-01

Full Text Available This attempt dedicated to the solution of buoyancy effect over a stretching sheet in existence of MHD stagnation point flow with convective boundary conditions. Thermophoresis and Brownian motion aspects are included. Incompressible fluid is electrically conducted in the presence of varying magnetic field. Boundary layer analysis is used to develop the mathematical formulation. Zero mass flux condition is considered at the boundary. Non-linear ordinary differential system of equations is constructed by means of proper transformations. Interval of convergence via numerical data and plots are developed. Characteristics of involved variables on the velocity, temperature and concentration distributions are sketched and discussed. Features of correlated parameters on Cf and Nu are examined by means of tables. It is found that buoyancy ratio and magnetic parameters increase and reduce the velocity field. Further opposite feature is noticed for higher values of thermophoresis and Brownian motion parameters on concentration distribution. Keywords: Stagnation point, MHD, Nanoparticles, Zero mass flux condition

Local similar solution of MHD stagnation point flow in Carreau fluid over a non-linear stretched surface with double stratified medium

Directory of Open Access Journals (Sweden)

M. Farooq

Full Text Available This article studies MHD double stratified stagnation point flow of Carreau fluid towards a non linear stretchable surface with radiation. Features of heat and mass transfer are evaluated by using convective boundary conditions. Resulting nonlinear problems are solved and studied for the velocity, temperature and concentration fields. Heat and mass transfer rates in addition to skin friction are discussed. Besides this for the verification of the present findings, the results of presented analysis have been compared with the available works in particular situations and reasonable agreement is noted. Keywords: Convective boundary condition, Thermal radiation, Double stratification, Stagnation point flow

Male-mediated developmental toxicity

International Nuclear Information System (INIS)

Anderson, Diana

2005-01-01

In recent years, the public has become more aware that exposure of males to certain agents can adversely affect their offspring and cause infertility and cancer. The hazards associated with exposure to ionising radiation have been recognised for nearly a century, but interest was aroused when a cluster of leukaemia cases was identified in young children living in Seascale, close to the nuclear processing plant at Sellafield in West Cumbria. There was a civil court case on behalf of two of the alleged victims of paternal irradiation at Seascale against British Nuclear Fuels. The case foundered on 'the balance of probabilities'. Nevertheless, there was support for paternal exposure from Japanese experimental X-ray studies in mice. The tumours were clearly heritable as shown by F2 transmission. Also, effects of a relatively non-toxic dose of radiation (1Gy) on cell proliferation transmitted to the embryo were manifested in the germ line of adult male mice even after two generations. In addition in humans, smoking fathers appear to give rise to tumours in the F 1 generation. Using rodent models, developmental abnormalities/congenital malformations and tumours can be studied after exposure of males in an extended dominant lethal assay and congenital malformations can be determined which have similar manifestations in humans. The foetuses can also be investigated for skeletal malformations and litters can be allowed to develop to adulthood when tumours, if present, can be observed. Karyotype analysis can be performed on foetuses and adult offspring to determine if induced genetic damage can be transmitted. Using this study design, cyclophosphamide, 1,3-butadiene and urethane have been examined and each compound produced positive responses: cyclophosphamide in all endpoints examined, 1,3-butadiene in some and urethane only produced liver tumours in F 1 male offspring. This suggests the endpoints are determined by independent genetic events. The results from heritable

Developmental immunotoxicity testing of 4-methyl anisole.

Science.gov (United States)

Tonk, Elisa C M; Verhoef, Aart; Gremmer, Eric R; van Loveren, Henk; Piersma, Aldert H

2015-07-01

The developmental immunotoxicity of 4-methyl anisole (4MA) was investigated in the rat. Four study designs were used, with either premating or post-weaning onset of exposure, continued to postnatal day 50, and with or without additional oral gavage of pups from postnatal day 10 onward. Reduced litter size (benchmark dose lower confidence limit (BMDL) 80mg/kg bw/day) was the most sensitive developmental parameter, with pup relative organ weight effects observed at similar BMDLs, in the absence of maternal toxicity. Eosinophil numbers were reduced at lower doses (BMDL 16mg/kg bw/day). KLH challenge resulted in increased IL-13 and TNF-α responses, and variably reduced IgG production (BMDL 27mg/kg bw/day). T4 levels were reduced by 11% at maximum with a BMDL of 73mg/kg bw/day. Differences between exposure cohorts were limited and were considered to be without biological significance. This study shows that 4MA induces developmental immunotoxicity at doses below those inducing developmental and general toxicity. These observations being independent of the study designs applied suggest that the post-weaning period, included in all designs, is the most relevant sensitive period for inducing 4MA mediated developmental immunotoxicity. Moreover, this study stresses the importance of including developmental immunotoxicity testing by default in regulatory toxicology. Copyright © 2015 Elsevier Inc. All rights reserved.

Expectations from different perspectives on future work outcome of young adults with intellectual and developmental disabilities

NARCIS (Netherlands)

Holwerda, Anja; Brouwer, Sandra; de Boer, Michiel R.; Groothoff, Johan W.; van der Klink, Jac J. L.

2015-01-01

Purpose Expectations strongly influence future employment outcomes and social networks seem to mediate employment success of young adults with intellectual and developmental disabilities. The aim of this study is to examine the expectations of young adults with intellectual and developmental

Expectations from Different Perspectives on Future Work Outcome of Young Adults with Intellectual and Developmental Disabilities

NARCIS (Netherlands)

Holwerda, A.; Brouwer, S.; de Boer, M.R.; Groothoff, J.W.; van der Klink, J.J.L.

2015-01-01

Purpose Expectations strongly influence future employment outcomes and social networks seem to mediate employment success of young adults with intellectual and developmental disabilities. The aim of this study is to examine the expectations of young adults with intellectual and developmental

Expectations from Different Perspectives on Future Work Outcome of Young Adults with Intellectual and Developmental Disabilities

NARCIS (Netherlands)

Holwerda, Anja; Brouwer, Sandra; de Boer, Michiel R.; Groothoff, Johan W.; van der Klink, Jac J. L.

Purpose Expectations strongly influence future employment outcomes and social networks seem to mediate employment success of young adults with intellectual and developmental disabilities. The aim of this study is to examine the expectations of young adults with intellectual and developmental

DAF-16/FOXO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage.

Science.gov (United States)

Mueller, Michael M; Castells-Roca, Laia; Babu, Vipin; Ermolaeva, Maria A; Müller, Roman-Ulrich; Frommolt, Peter; Williams, Ashley B; Greiss, Sebastian; Schneider, Jennifer I; Benzing, Thomas; Schermer, Bernhard; Schumacher, Björn

2014-12-01

Genome maintenance defects cause complex disease phenotypes characterized by developmental failure, cancer susceptibility and premature ageing. It remains poorly understood how DNA damage responses function during organismal development and maintain tissue functionality when DNA damage accumulates with ageing. Here we show that the FOXO transcription factor DAF-16 is activated in response to DNA damage during development, whereas the DNA damage responsiveness of DAF-16 declines with ageing. We find that in contrast to its established role in mediating starvation arrest, DAF-16 alleviates DNA-damage-induced developmental arrest and even in the absence of DNA repair promotes developmental growth and enhances somatic tissue functionality. We demonstrate that the GATA transcription factor EGL-27 co-regulates DAF-16 target genes in response to DNA damage and together with DAF-16 promotes developmental growth. We propose that EGL-27/GATA activity specifies DAF-16-mediated DNA damage responses to enable developmental progression and to prolong tissue functioning when DNA damage persists.

Maternal Immune-Mediated Conditions, Autism Spectrum Disorders, and Developmental Delay

Science.gov (United States)

Lyall, Kristen; Ashwood, Paul; Van de Water, Judy; Hertz-Picciotto, Irva

2014-01-01

The maternal immune system may play a role in offspring neurodevelopment. We examined whether maternal autoimmune disease, asthma, and allergy were associated with child autism spectrum disorder (ASD) and developmental delay without autism (DD) using 560 ASD cases, 391 typically developing controls, and 168 DD cases from the CHildhood Autism Risk…

Teen Dating Violence, Sexual Harassment, and Bullying Among Middle School Students: Examining Mediation and Moderated Mediation by Gender.

Science.gov (United States)

Cutbush, Stacey; Williams, Jason; Miller, Shari

2016-11-01

This longitudinal study tested whether sexual harassment perpetration mediates the relationship between bullying perpetration and teen dating violence (TDV) perpetration and tested moderated mediation by assessing whether the developmental pathway varies by gender among middle school-aged youth. Although TDV has been associated with bullying and sexual harassment, the developmental relationship among all three behaviors has rarely been examined, especially by gender. The data were collected from one cohort of seventh grade middle school students (N = 612) from four schools. Students were surveyed every 6 months during seventh and eighth grades for a total of four waves of data collection. Structural equation modeling (SEM) was conducted to address the study aims, consisting of three stages: measurement models, mediation, and moderated mediation (otherwise known as Contrast of Mediated Effects). Results indicate no evidence of mediation. However, in the overall model, bullying and sexual harassment both emerged as significant predictors of TDV at a later time point. Among girls, only bullying significantly predicted TDV at a later time point, and, among boys, only sexual harassment significantly predicted TDV at a later time point. Prevention programs that target bullying and sexual harassment perpetration may reduce later perpetration of TDV. Further research is needed to disentangle the temporal relationships between these aggressive behaviors among youth.

Letter and Colour Matching Tasks: Parametric Measures of Developmental Working Memory Capacity

OpenAIRE

Powell, Tamara L.; Arsalidou, Marie; Vogan, Vanessa M.; Taylor, Margot J.

2014-01-01

We investigated the mediating role of interference in developmental assessments of working memory (WM) capacity across childhood, adolescence, and young adulthood. One hundred and forty-two participants completed two versions of visuospatial (colour matching task, CMT) and verbal (letter matching task, LMT) WM tasks, which systematically varied cognitive load in a high and low interference condition. Results showed similar developmental trajectories across high interference contexts (CMT- and...

Rise, stagnation, and rise of Danish women's life expectancy

DEFF Research Database (Denmark)

Lindahl-Jacobsen, Rune; Rau, Roland; Jeune, Bernard

2016-01-01

Health conditions change from year to year, with a general tendency in many countries for improvement. These conditions also change from one birth cohort to another: some generations suffer more adverse events in childhood, smoke more heavily, eat poorer diets, etc., than generations born earlier...... favor forecasts that hinge on cohort differences. We use a combination of age decomposition and exchange of survival probabilities between countries to study the remarkable recent history of female life expectancy in Denmark, a saga of rising, stagnating, and now again rising lifespans. The gap between...... female life expectancy in Denmark vs. Sweden grew to 3.5 y in the period 1975-2000. When we assumed that Danish women born 1915-1945 had the same survival probabilities as Swedish women, the gap remained small and roughly constant. Hence, the lower Danish life expectancy is caused by these cohorts...

Enhanced excitatory input to MCH neurons during developmental period of high food intake is mediated by GABA

Science.gov (United States)

Li, Ying; van den Pol, Anthony N.

2010-01-01

In contrast to the local axons of GABA neurons of the cortex and hippocampus, lateral hypothalamic neurons containing melanin concentrating hormone (MCH) and GABA send long axons throughout the brain and play key roles in energy homeostasis and mental status. In adults, MCH neurons maintain a hyperpolarized membrane potential and most of the synaptic input is inhibitory. In contrast, we found that developing MCH neurons received substantially more excitatory synaptic input. Based on gramicidicin-perforated patch recordings in hypothalamic slices from MCH-GFP transgenic mice, we found that GABA was the primary excitatory synaptic transmitter in embryonic and neonatal ages up to postnatal day 10. Surprisingly, glutamate assumed only a minor excitatory role, if any. GABA plays a complex role in developing MCH neurons, with its actions conditionally dependent on a number of factors. GABA depolarization could lead to an increase in spikes either independently or in summation with other depolarizing stimuli, or alternately, depending on the relative timing of other depolarizing events, could lead to shunting inhibition. The developmental shift from depolarizing to hyperpolarizing occurred later in the dendrites than in the cell body. Early GABA depolarization was based on a Cl− dependent inward current. An interesting secondary depolarization in mature neurons that followed an initial hyperpolarization was based on a bicarbonate mechanism. Thus during the early developmental period when food consumption is high, MCH neurons are more depolarized than in the adult, and an increased level of excitatory synaptic input to these orexigenic cells is mediated by GABA. PMID:19955372

Defining the Locus of Developmental Differences in Children's Causal Reasoning

Science.gov (United States)

Siegler, Robert S.

1975-01-01

Five experiments were performed in the area of children's causal reasoning to validate a previously reported developmental difference, to examine the role of a possible mediating mechanism, and to test a number of competing theoretical interpretations. (GO)

Economics of thinning stagnated ponderosa pine sapling stands in the pine-grass areas of central Washington.

Science.gov (United States)

Robert W. Sassaman; James W. Barrett; Justin G. Smith

1972-01-01

Present net worth values earned by investments in precommercial thinning of stagnated ponderosa pine sapling stands are reported for three stocking levels. Thirteen timber management regimes are ranked by their returns from timber only, and 22 regimes are ranked according to their returns from timber and forage, with and without the allowable cut effect.

MEDIATOR18 and MEDIATOR20 confer susceptibility to Fusarium oxysporum in Arabidopsis thaliana

Science.gov (United States)

Stiller, Jiri; Davoine, Celine; Björklund, Stefan; Manners, John M.; Kazan, Kemal; Schenk, Peer M.

2017-01-01

The conserved protein complex known as Mediator conveys transcriptional signals by acting as an intermediary between transcription factors and RNA polymerase II. As a result, Mediator subunits play multiple roles in regulating developmental as well as abiotic and biotic stress pathways. In this report we identify the head domain subunits MEDIATOR18 and MEDIATOR20 as important susceptibility factors for Fusarium oxysporum infection in Arabidopsis thaliana. Mutants of MED18 and MED20 display down-regulation of genes associated with jasmonate signaling and biosynthesis while up-regulation of salicylic acid associated pathogenesis related genes and reactive oxygen producing and scavenging genes. We propose that MED18 and MED20 form a sub-domain within Mediator that controls the balance of salicylic acid and jasmonate associated defense pathways. PMID:28441405

Developmental endothelial locus-1 modulates platelet-monocyte interactions and instant blood-mediated inflammatory reaction in islet transplantation.

Science.gov (United States)

Kourtzelis, Ioannis; Kotlabova, Klara; Lim, Jong-Hyung; Mitroulis, Ioannis; Ferreira, Anaisa; Chen, Lan-Sun; Gercken, Bettina; Steffen, Anja; Kemter, Elisabeth; Klotzsche-von Ameln, Anne; Waskow, Claudia; Hosur, Kavita; Chatzigeorgiou, Antonios; Ludwig, Barbara; Wolf, Eckhard; Hajishengallis, George; Chavakis, Triantafyllos

2016-04-01

Platelet-monocyte interactions are strongly implicated in thrombo-inflammatory injury by actively contributing to intravascular inflammation, leukocyte recruitment to inflamed sites, and the amplification of the procoagulant response. Instant blood-mediated inflammatory reaction (IBMIR) represents thrombo-inflammatory injury elicited upon pancreatic islet transplantation (islet-Tx), thereby dramatically affecting transplant survival and function. Developmental endothelial locus-1 (Del-1) is a functionally versatile endothelial cell-derived homeostatic factor with anti-inflammatory properties, but its potential role in IBMIR has not been previously addressed. Here, we establish Del-1 as a novel inhibitor of IBMIR using a whole blood-islet model and a syngeneic murine transplantation model. Indeed, Del-1 pre-treatment of blood before addition of islets diminished coagulation activation and islet damage as assessed by C-peptide release. Consistently, intraportal islet-Tx in transgenic mice with endothelial cell-specific overexpression of Del-1 resulted in a marked decrease of monocytes and platelet-monocyte aggregates in the transplanted tissues, relative to those in wild-type recipients. Mechanistically, Del-1 decreased platelet-monocyte aggregate formation, by specifically blocking the interaction between monocyte Mac-1-integrin and platelet GPIb. Our findings reveal a hitherto unknown role of Del-1 in the regulation of platelet-monocyte interplay and the subsequent heterotypic aggregate formation in the context of IBMIR. Therefore, Del-1 may represent a novel approach to prevent or mitigate the adverse reactions mediated through thrombo-inflammatory pathways in islet-Tx and perhaps other inflammatory disorders involving platelet-leukocyte aggregate formation.

Slab Penetration vs. Slab Stagnation: Mantle Reflectors as an Indicator

Science.gov (United States)

Okeler, A.; Gu, Y. J.; Schultz, R.; Contenti, S. M.

2011-12-01

Subducting oceanic lithosphere along convergent margins may stagnate near the base of the upper mantle or penetrate into the lower mantle. These dynamic processes cause extensive thermal and compositional variations, which can be observed in terms of impedance contrast (reflectivity) and topography of mantle transition zone (MTZ) discontinuities, i.e., 410- and 660-km discontinuities. In this study, we utilize ~ 15000 surface-reflected shear waves (SS) and their precursory arrivals (S410S and S660S) to analyze subduction related deformations on mantle reflectivity structure. We apply pre-stack, time-to-depth migration technique to SS precursors, and move weak underside reflections using PREM-predicted travel-time curves. Common Mid-point gathers are formed to investigate structure under the western Pacific, south America, and Mediterranean convergent boundaries. In general, mantle reflectivity structures are consistent with previous seismic tomography models. In regions of slab penetration (e.g., southern Kurile arc, Aegean Sea), our results show 1) a substantial decrease in S660S amplitude, and 2) strong lower mantle reflector(s) at ~ 900 km depth. These reflective structures are supported by zones of high P and S velocities extending into the lower mantle. Our 1-D synthetic simulations suggest that the decreasing S660S amplitudes are, at least partially, associated with shear wave defocusing due to changes in reflector depth (by ±20 km) within averaging bin. Assuming a ~500 km wide averaging area, a dipping reflector with 6-8 % slope can reduce the amplitude of a SS precursor by ~50%. On the other hand, broad depressions with strong impedance contrast at the base of the MTZ characterize the regions of slab stagnation, such as beneath the Tyrrhenian Sea and northeastern China. For the latter region, substantial topography on the 660-km discontinuity west of the Wadati-Benioff zone suggests that the stagnant part of the Pacific plate across Honshu arc is not

Developmental expression of Manduca shade, the P450 mediating the final step in molting hormone synthesis

DEFF Research Database (Denmark)

Rewitz, Kim; Rybczynski, Robert; Warren, James T.

2006-01-01

body and epidermis with very low expression in the prothoracic gland and nervous system. Developmental variations in E20MO enzymatic activity are almost perfectly correlated with comparable changes in the gene expression of Msshd in the fat body and midgut during the fifth instar and the beginning...... gene shade (shd; CYP314A1) that encodes the E20MO in the tobacco hornworm, Manduca sexta. Manduca Shd (MsShd) mediates the conversion of E to 20E when expressed in Drosophila S2 cells. In accord with the central dogma, the data show that Msshd is expressed mainly in the midgut, Malpighian tubules, fat...... of pupal-adult development. The results indicate three successive and overlapping peaks of expression in the fat body, midgut and Malpighian tubules, respectively, during the fifth larval instar. The data suggest that precise tissue-specific transcriptional regulation controls the levels, and thereby...

On the freestream matching condition for stagnation point turbulent flows

Science.gov (United States)

Speziale, C. G.

1989-01-01

The problem of plane stagnation point flow with freestream turbulence is examined from a basic theoretical standpoint. It is argued that the singularity which arises from the standard kappa-epsilon model is not due to a defect in the model but results from the use of an inconsistent freestream boundary condition. The inconsistency lies in the implementation of a production equals dissipation equilibrium hypothesis in conjunction with a freestream mean velocity field that corresponds to homogeneous plane strain - a turbulent flow which does not reach such a simple equilibrium. Consequently, the adjustment that has been made in the constants of the epsilon-transport equation to eliminate this singularity is not self-consistent since it is tantamount to artificially imposing an equilibrium structure on a turbulent flow which is known not to have one.

Demographic stagnation and decline in Spain: A cause for concern?

Directory of Open Access Journals (Sweden)

Serrano-Martínez José-María

2018-03-01

Full Text Available For years, the Spanish population has been rapidly ageing, showing signs of atony and stagnation. Between 1996 and 2007, in a phase of economic growth, the entry of foreign immigrants drove a global increase in population. But after the economic recession migratory flows show negative net balances. Our objective is to explain and confirm the demographic regression suffered by Spain. We are also interested in showing how the recent and intense immigration process has failed to generate significant changes in natural demographic characteristics and trends. National censuses, published by the National Institute of Statistics (INE, are our main source of demographic data. The analysis of the most recent relevant scientific literature has allowed us to compare opinions and discuss results. The data confirm an uncertain and worrying future for the Spanish population.

Is Season of Birth Related to Developmental Dyslexia?

Science.gov (United States)

Donfrancesco, Renato; Iozzino, Roberto; Caruso, Barbara; Ferrante, Laura; Mugnaini, Daniele; Talamo, Alessandra; Miano, Silvia; Dimitri, Andrea; Masi, Gabriele

2010-01-01

Different moderators/mediators of risk are involved in developmental dyslexia (DD), but data are inconsistent. We explored the prevalence of season of birth and its association with gender and age of school entry in an Italian sample of dyslexic children compared to an Italian normal control group. The clinical sample included 498 children (345…

The developmental outcomes of P0-mediated ARGONAUTE destabilization in tomato.

Science.gov (United States)

Hendelman, Anat; Kravchik, Michael; Stav, Ran; Zik, Moriyah; Lugassi, Nitsan; Arazi, Tzahi

2013-01-01

The plant protein ARGONAUTE1 (AGO1) functions in multiple RNA-silencing pathways, including those of microRNAs, key regulators of growth and development. Genetic analysis of ago1 mutants with informative defects has provided valuable insights into AGO1's biological functions. Tomato encodes two AGO1 homologs (SlAGO1s), but mutants have not been described to date. To analyze SlAGO1s' involvement in development, we confirmed that both undergo decay in the presence of the Polerovirus silencing suppressor P0 and produce a transgenic responder line (OP:P0HA) that, upon transactivation, expresses P0 C-terminally fused to a hemagglutinin (HA) tag (P0HA) and destabilizes SlAGO1s at the site of expression. By crossing OP:P0HA with a battery of driver lines, constitutive as well as organ- and stage-specific SlAGO1 downregulation was induced in the F1 progeny. Activated plants exhibited various developmental phenotypes that partially overlapped with those of Arabidopsis ago1 mutants. Plants that constitutively expressed P0HA had reduced SlAGO1 levels and increased accumulation of miRNA targets, indicating compromised SlAGO1-mediated silencing. Consistent with this, they exhibited pleiotropic morphological defects and their growth was arrested post-germination. Transactivation of P0HA in young leaf and floral organ primordia dramatically modified corresponding organ morphology, including the radialization of leaflets, petals and anthers, suggesting that SlAGO1s' activities are required for normal lateral organ development and polarity. Overall, our results suggest that the OP:P0HA responder line can serve as a valuable tool to suppress SlAGO1 silencing pathways in tomato. The suppression of additional SlAGOs by P0HA and its contribution to the observed phenotypes awaits investigation.

The role of atmospheric nuclear explosions on the stagnation of global warming in the mid 20th century

Science.gov (United States)

Fujii, Yoshiaki

2011-04-01

This study suggests that the cause of the stagnation in global warming in the mid 20th century was the atmospheric nuclear explosions detonated between 1945 and 1980. The estimated GST drop due to fine dust from the actual atmospheric nuclear explosions based on the published simulation results by other researchers (a single column model and Atmosphere-Ocean General Circulation Model) has served to explain the stagnation in global warming. Atmospheric nuclear explosions can be regarded as full-scale in situ tests for nuclear winter. The non-negligible amount of GST drop from the actual atmospheric explosions suggests that nuclear winter is not just a theory but has actually occurred, albeit on a small scale. The accuracy of the simulations of GST by IPCC would also be improved significantly by introducing the influence of fine dust from the actual atmospheric nuclear explosions into their climate models; thus, global warming behavior could be more accurately predicted.

Heat transfer in an axisymmetric stagnation flow at high Reynolds numbers on a cylinder using perturbation techniques

International Nuclear Information System (INIS)

Rahimi, A. B.

2003-01-01

Although there are many papers on the subject of heat transfer in an axisymmetric stagnation flow on a cylinder, the available knowledge is mainly for low Reynolds numbers and not much information exists for the same problem at large Reynolds numbers. In this work, the problem of heat transfer in an axisymmetric stagnation flow on a cylinder is solved at large Reynolds numbers using perturbation techniques. Starting from Navier-Stokes equations within a boundary layer approximation and using similarity transformations, the governing equations are obtained in the form of differential equations. The inverse of the Reynolds number is introduced as the perturbation parameter. This parameter appears in front of the highest-order terms and, as it tends to zero, reduces the order of the governing equations and produces singularities. In this paper, the flow field is divided into two regions; rapid changes in the region near wall and slow changes away from the wall. Thus, the flow is found to have dual-layer characteristics. Using inner and outer expansion produces uniform values of the relevant quantities

Standard Practice for Exposure of Solar Collector Cover Materials to Natural Weathering Under Conditions Simulating Stagnation Mode

CERN Document Server

American Society for Testing and Materials. Philadelphia

1992-01-01

1.1 This practice covers a procedure for the exposure of solar collector cover materials to the natural weather environment at elevated temperatures that approximate stagnation conditions in solar collectors having a combined back and edge loss coefficient of less than 1.5 W/(m2 · °C). 1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials. 1.3 This practice does not apply to cover materials for evacuated collectors, photovoltaic cells, flat-plate collectors having a combined back and edge loss coefficient greater than 1.5 W/(m2 ·° C), or flat-plate collectors whose design incorporates means for limiting temperatures during stagnation. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard t...

Letter and Colour Matching Tasks: Parametric Measures of Developmental Working Memory Capacity

Directory of Open Access Journals (Sweden)

Tamara L. Powell

2014-01-01

Full Text Available We investigated the mediating role of interference in developmental assessments of working memory (WM capacity across childhood, adolescence, and young adulthood. One hundred and forty-two participants completed two versions of visuospatial (colour matching task, CMT and verbal (letter matching task, LMT WM tasks, which systematically varied cognitive load in a high and low interference condition. Results showed similar developmental trajectories across high interference contexts (CMT- and LMT-Complex and divergent developmental growth patterns across low interference contexts (CMT- and LMT-Simple. Performance on tasks requiring greater cognitive control was in closer agreement with developmental predictions relative to simple recall guided tasks that rely solely on the storage components of WM. These findings suggest that developmental WM capacity, as measured by the CMT and LMT paradigms, can be better quantified using high interference contexts, in both content domains, and demonstrate steady increases in WM through to mid-adolescence.

Flow stagnation volume and abdominal aortic aneurysm growth: Insights from patient-specific computational flow dynamics of Lagrangian-coherent structures.

Science.gov (United States)

Joly, Florian; Soulez, Gilles; Garcia, Damien; Lessard, Simon; Kauffmann, Claude

2018-01-01

Abdominal aortic aneurysms (AAA) are localized, commonly-occurring dilations of the aorta. When equilibrium between blood pressure (loading) and wall mechanical resistance is lost, rupture ensues, and patient death follows, if not treated immediately. Experimental and numerical analyses of flow patterns in arteries show direct correlations between wall shear stress and wall mechano-adaptation with the development of zones prone to thrombus formation. For further insights into AAA flow topology/growth interaction, a workout of patient-specific computational flow dynamics (CFD) is proposed to compute finite-time Lyapunov exponents and extract Lagrangian-coherent structures (LCS). This computational model was first compared with 4-D phase-contrast magnetic resonance imaging (MRI) in 5 patients. To better understand the impact of flow topology and transport on AAA growth, hyperbolic, repelling LCS were computed in 1 patient during 8-year follow-up, including 9 volumetric morphologic AAA measures by computed tomography-angiography (CTA). LCS defined barriers to Lagrangian jet cores entering AAA. Domains enclosed between LCS and the aortic wall were considered to be stagnation zones. Their evolution was studied during AAA growth. Good correlation - 2-D cross-correlation coefficients of 0.65, 0.86 and 0.082 (min, max, SD) - was obtained between numerical simulations and 4-D MRI acquisitions in 6 specific cross-sections from 4 patients. In follow-up study, LCS divided AAA lumens into 3 dynamically-isolated zones: 2 stagnation volumes lying in dilated portions of the AAA, and circulating volume connecting the inlet to the outlet. The volume of each zone was tracked over time. Although circulating volume remained unchanged during 8-year follow-up, the AAA lumen and main stagnation zones grew significantly (8 cm 3 /year and 6 cm 3 /year, respectively). This study reveals that transient transport topology can be quantified in patient-specific AAA during disease progression

Stagnation point flow towards nonlinear stretching surface with Cattaneo-Christov heat flux

Science.gov (United States)

Hayat, T.; Zubair, M.; Ayub, M.; Waqas, M.; Alsaedi, A.

2016-10-01

Here the influence of the non-Fourier heat flux in a two-dimensional (2D) stagnation point flow of Eyring-Powell liquid towards a nonlinear stretched surface is reported. The stretching surface is of variable thickness. Thermal conductivity of fluid is taken temperature-dependent. Ordinary differential systems are obtained through the implementation of meaningful transformations. The reduced non-dimensional expressions are solved for the convergent series solutions. Convergence interval is obtained for the computed solutions. Graphical results are displayed and analyzed in detail for the velocity, temperature and skin friction coefficient. The obtained results reveal that the temperature gradient enhances when the thermal relaxation parameter is increased.

Exposure of children with developmental delay to social determinants of poor health: cross-sectional case record review study.

Science.gov (United States)

Emerson, E; Brigham, P

2015-03-01

Research on child development in general has highlighted the importance that the family environment plays in mediating the pathway between exposure to low socio-economic position (SEP) and child well-being. While child developmental models in intellectual disability have highlighted the interplay between social context, family environment and child development, little empirical work has attempted to formally evaluate the evidence in support of specific mediating pathways between low SEP and child outcomes. Secondary analysis of cross-sectional confidentialized needs analysis data collected in three Primary Care Trusts in England covering a total population of 1.25 million people. Case record reviews were undertaken for 46 023 households, 2236 (4.9%) of which contained a child in the target age range with developmental delay. Children with developmental delay, when compared with their non-disabled peers, were at significantly increased risk of poorer health outcomes and of being exposed to a wide range of social determinants of poor health. Controlling for between-group differences in exposure to social determinants of poor health reduced the risk of developmental delay being associated with poorer health outcomes by 45% for behaviour problems and 89% for risk of significant harm. For children with developmental delay, parenting difficulties appears to play a particularly significant role in partially mediating the effects of low SEP. The findings of the present study point to the potential effectiveness of family-focused early intervention to prevent the emergence and escalation of behavioural difficulties and health problems in children with developmental delay. © 2014 John Wiley & Sons Ltd.

The role of developmental plasticity and epigenetics in human health.

Science.gov (United States)

Gluckman, Peter D; Hanson, Mark A; Low, Felicia M

2011-03-01

Considerable epidemiological, experimental and clinical data have amassed showing that the risk of developing disease in later life is dependent on early life conditions, mainly operating within the normative range of developmental exposures. This relationship reflects plastic responses made by the developing organism as an evolved strategy to cope with immediate or predicted circumstances, to maximize fitness in the context of the range of environments potentially faced. There is now increasing evidence, both in animals and humans, that such developmental plasticity is mediated in part by epigenetic mechanisms. However, recognition of the importance of developmental plasticity as an important factor in influencing later life health-particularly within the medical and public health communities-is low, and we argue that this indifference cannot be sustained in light of the growing understanding of developmental processes and the rapid rise in the prevalence of obesity and metabolic disease globally. Copyright © 2011 Wiley-Liss, Inc.

Mediator subunit18 controls flowering time and floral organ identity in Arabidopsis.

Directory of Open Access Journals (Sweden)

Zhengui Zheng

Full Text Available Mediator is a conserved multi-protein complex that plays an important role in regulating transcription by mediating interactions between transcriptional activator proteins and RNA polymerase II. Much evidence exists that Mediator plays a constitutive role in the transcription of all genes transcribed by RNA polymerase II. However, evidence is mounting that specific Mediator subunits may control the developmental regulation of specific subsets of RNA polymerase II-dependent genes. Although the Mediator complex has been extensively studied in yeast and mammals, only a few reports on Mediator function in flowering time control of plants, little is known about Mediator function in floral organ identity. Here we show that in Arabidopsis thaliana, MEDIATOR SUBUNIT 18 (MED18 affects flowering time and floral organ formation through FLOWERING LOCUS C (FLC and AGAMOUS (AG. A MED18 loss-of-function mutant showed a remarkable syndrome of later flowering and altered floral organ number. We show that FLC and AG mRNA levels and AG expression patterns are altered in the mutant. Our results support parallels between the regulation of FLC and AG and demonstrate a developmental role for Mediator in plants.

Parental Bonds, Attachment Anxiety, Media Susceptibility, and Body Dissatisfaction: A Mediation Model

Science.gov (United States)

Patton, Sarah C.; Beaujean, A. Alexander; Benedict, Helen E.

2014-01-01

The developmental trajectory of body image dissatisfaction is unclear. Researchers have investigated sociocultural and developmental risk factors; however, the literature needs an integrative etiological model. In 2009, Cheng and Mallinckrodt proposed a dual mediation model, positing that poor-quality parental bonds, via the mechanisms of…

3D Stagnation instabilities in MagLIF loads on the Z Generator

Science.gov (United States)

Jennings, Christopher

2017-10-01

Experiments with Magnetized Liner Inertial Fusion (MagLIF) loads have successfully demonstrated the premise of magnetized fusion. While these experiments are increasingly well diagnosed, many of the measurements (particularly during stagnation) are time integrated, limited in spatial resolution or require additional assumptions to interpret in the context of a structured, rapidly evolving system. As such, there is some ambiguity over what may be limiting performance. Poor laser coupling in preheating the fuel prior to implosion has been suggested as a mechanism. Mix of high Z contaminants that cool the fuel is also a significant concern. In addition, time integrated crystal imaging has shown significant structure in the final fuel assembly indicating potential disruption from instabilities. Understanding the balance between these degradation mechanisms is vital to progress with MagLif. We compare several sets of experimental data with synthetically generated data from systematically varied 3D resistive-MHD simulations to gain insight into the relative contributions of different degradation mechanisms. We demonstrate how some measurements strongly indicate disruption from liner material penetrating into the fuel at stagnation, and discuss the implications this has for how MagLif targets work and scale to larger drive currents. We then explore the extent to which different combinations of instability development, current delivery, high-Z mix into the fuel and initial laser deposition can be differentiated in our existing measurements. Better determining the dominant degradation mechanisms can directly influence the direction we take to improve performance, or our confidence in scaling these targets to higher currents. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. DoE's NNSA under contract DE-NA0003525.

On the Analytical Solution of Non-Orthogonal Stagnation Point Flow towards a Stretching Sheet

DEFF Research Database (Denmark)

Kimiaeifar, Amin; Bagheri, G. H.; Barari, Amin

2011-01-01

An analytical solution for non-orthogonal stagnation point for the steady flow of a viscous and incompressible fluid is presented. The governing nonlinear partial differential equations for the flow field are reduced to ordinary differential equations by using similarity transformations existed...... in the literature and are solved analytically by means of the Homotopy Analysis Method (HAM). The comparison of results from this paper and those published in the literature confirms the precise accuracy of the HAM. The resulting analytical equation from HAM is valid for entire physical domain and effective...

Enhanced excitatory input to melanin concentrating hormone neurons during developmental period of high food intake is mediated by GABA.

Science.gov (United States)

Li, Ying; van den Pol, Anthony N

2009-12-02

In contrast to the local axons of GABA neurons of the cortex and hippocampus, lateral hypothalamic neurons containing melanin concentrating hormone (MCH) and GABA send long axons throughout the brain and play key roles in energy homeostasis and mental status. In adults, MCH neurons maintain a hyperpolarized membrane potential and most of the synaptic input is inhibitory. In contrast, we found that developing MCH neurons received substantially more excitatory synaptic input. Based on gramicidin-perforated patch recordings in hypothalamic slices from MCH-green fluorescent protein transgenic mice, we found that GABA was the primary excitatory synaptic transmitter in embryonic and neonatal ages up to postnatal day 10. Surprisingly, glutamate assumed only a minor excitatory role, if any. GABA plays a complex role in developing MCH neurons, with its actions conditionally dependent on a number of factors. GABA depolarization could lead to an increase in spikes either independently or in summation with other depolarizing stimuli, or alternately, depending on the relative timing of other depolarizing events, could lead to shunting inhibition. The developmental shift from depolarizing to hyperpolarizing occurred later in the dendrites than in the cell body. Early GABA depolarization was based on a Cl(-)-dependent inward current. An interesting secondary depolarization in mature neurons that followed an initial hyperpolarization was based on a bicarbonate mechanism. Thus during the early developmental period when food consumption is high, MCH neurons are more depolarized than in the adult, and an increased level of excitatory synaptic input to these orexigenic cells is mediated by GABA.

Early developmental responses to seedling environment modulate later plasticity to light spectral quality.

Directory of Open Access Journals (Sweden)

Eric J B von Wettberg

Full Text Available Correlations between developmentally plastic traits may constrain the joint evolution of traits. In plants, both seedling de-etiolation and shade avoidance elongation responses to crowding and foliage shade are mediated by partially overlapping developmental pathways, suggesting the possibility of pleiotropic constraints. To test for such constraints, we exposed inbred lines of Impatiens capensis to factorial combinations of leaf litter (which affects de-etiolation and simulated foliage shade (which affects phytochrome-mediated shade avoidance. Increased elongation of hypocotyls caused by leaf litter phenotypically enhanced subsequent elongation of the first internode in response to low red:far red (R:FR. Trait expression was correlated across litter and shade conditions, suggesting that phenotypic effects of early plasticity on later plasticity may affect variation in elongation traits available to selection in different light environments.

Hall effect on magnetohydrodynamic instabilities at an elliptic magnetic stagnation line

Science.gov (United States)

Spies, Günther O.; Faghihi, Mustafa

1987-06-01

To answer the question whether the Hall effect removes the unphysical feature of ideal magnetohydrodynamics of predicting small wavelength kink instabilities at any elliptic magnetic stagnation line, a normal mode analysis is performed of the motion of an incompressible Hall fluid about cylindrical Z-pinch equilibria with circular cross sections. The eigenvalue loci in the complex frequency plane are derived for the equilibrium with constant current density. Every particular mode becomes stable as the Hall parameter exceeds a critical value. This value, however, depends on the mode such that it increases to infinity as the ideal growth rate decreases to zero, implying that there always remains an infinite number of slowly growing instabilities. Correspondingly, the stability criterion for equilibria with arbitrary current distributions is independent of the Hall parameter.

Hall effect on magnetohydrodynamic instabilities at an elliptic magnetic stagnation line

International Nuclear Information System (INIS)

Spies, G.O.; Faghihi, M.

1987-01-01

To answer the question whether the Hall effect removes the unphysical feature of ideal magnetohydrodynamics of predicting small wavelength kink instabilities at any elliptic magnetic stagnation line, a normal mode analysis is performed of the motion of an incompressible Hall fluid about cylindrical Z-pinch equilibria with circular cross sections. The eigenvalue loci in the complex frequency plane are derived for the equilibrium with constant current density. Every particular mode becomes stable as the Hall parameter exceeds a critical value. This value, however, depends on the mode such that it increases to infinity as the ideal growth rate decreases to zero, implying that there always remains an infinite number of slowly growing instabilities. Correspondingly, the stability criterion for equilibria with arbitrary current distributions is independent of the Hall parameter

Testing inferences in developmental evolution: the forensic evidence principle.

Science.gov (United States)

Larsson, Hans C E; Wagner, Günter P

2012-09-01

Developmental evolution (DE) examines the influence of developmental mechanisms on biological evolution. Here we consider the question: "what is the evidence that allows us to decide whether a certain developmental scenario for an evolutionary change is in fact "correct" or at least falsifiable?" We argue that the comparative method linked with what we call the "forensic evidence principle" (FEP) is sufficient to conduct rigorous tests of DE scenarios. The FEP states that different genetically mediated developmental causes of an evolutionary transformation will leave different signatures in the development of the derived character. Although similar inference rules have been used in practically every empirical science, we expand this approach here in two ways: (1) we justify the validity of this principle with reference to a well-known result from mathematical physics, known as the symmetry principle, and (2) propose a specific form of the FEP for DE: given two or more developmental explanations for a certain evolutionary event, say an evolutionary novelty, then the evidence discriminating between these hypotheses will be found in the most proximal internal drivers of the derived character. Hence, a detailed description of the ancestral and derived states, and their most proximal developmental drivers are necessary to discriminate between various evolutionary developmental hypotheses. We discuss how this stepwise order of testing is necessary, establishes a formal test, and how skipping this order of examination may violate a more accurate examination of DE. We illustrate the approach with an example from avian digit evolution. © 2012 Wiley Periodicals, Inc.

Bulk damping of sound in superfluid 3He--4He under stagnation of the normal component

International Nuclear Information System (INIS)

Karchava, T.A.; Sanikidze, D.G.; Chkhaidze, N.D.

1983-01-01

The propagation of waves in superfluid 3 He-- 4 He solutions is considered under partial stagnation of the normal component. The wave processes in capillaries are presented as a superposition of the first sound, second sound, and viscous and diffusion waves. The damping coefficients are calculated for the modified first sound and for the thermal wave in superfluid 3 He-- 4 He solutions and related to the viscosity, thermal conductivity, diffusion, barodiffusion, and thermodiffusion coefficients

Cultural Mediation. The Usefulness of Selected Concepts of Developmental Psychology for Coaching and Mentoring Relations

OpenAIRE

Smorczewska, Barbara

2013-01-01

Some developmental psychological concepts, such as L. S. Vygotsky’s zone of proximal development or H. R. Schaffer’s joint involvement episodes, gave a new perspective in perceiving the process of teaching and development, by providing very detailed characteristics of the situation of acquiring competence in social relations. The mentioned concepts are based on a belief in the developmental potential of humans, and they perceive teaching as future-oriented. These assumptions are also characte...

Analysis of stagnation point flow of an upper-convected Maxwell fluid

Directory of Open Access Journals (Sweden)

Joseph E. Paullet

2017-12-01

Full Text Available Several recent papers have investigated the two-dimensional stagnation point flow of an upper-convected Maxwell fluid by employing a similarity change of variable to reduce the governing PDEs to a nonlinear third order ODE boundary value problem (BVP. In these previous works, the BVP was studied numerically and several conjectures regarding the existence and behavior of the solutions were made. The purpose of this article is to mathematically verify these conjectures. We prove the existence of a solution to the BVP for all relevant values of the elasticity parameter. We also prove that this solution has monotonically increasing first derivative, thus verifying the conjecture that no ``overshoot'' of the boundary condition occurs. Uniqueness results are presented for a large range of parameter space and bounds on the skin friction coefficient are calculated.

An Examination of Specific Child Behavior Problems as Predictors of Parenting Stress among Families of Children with Pervasive Developmental Disorders

Science.gov (United States)

Davis, Allyson L.; Neece, Cameron L.

2017-01-01

Introduction: Studies have shown that parents of children with pervasive developmental disorders (PDD) exhibit higher levels of stress than parents of typically developing children or children with other types of developmental delays (DD). This relationship appears to be mediated by elevated levels of behavior problems observed in children with…

Inertioelastic Flow Instability at a Stagnation Point

Science.gov (United States)

Burshtein, Noa; Zografos, Konstantinos; Shen, Amy Q.; Poole, Robert J.; Haward, Simon J.

2017-10-01

A number of important industrial applications exploit the ability of small quantities of high molecular weight polymer to suppress instabilities that arise in the equivalent flow of Newtonian fluids, a particular example being turbulent drag reduction. However, it can be extremely difficult to probe exactly how the polymer acts to, e.g., modify the streamwise near-wall eddies in a fully turbulent flow. Using a novel cross-slot flow configuration, we exploit a flow instability in order to create and study a single steady-state streamwise vortex. By quantitative experiment, we show how the addition of small quantities (parts per million) of a flexible polymer to a Newtonian solvent dramatically affects both the onset conditions for this instability and the subsequent growth of the axial vorticity. Complementary numerical simulations with a finitely extensible nonlinear elastic dumbbell model show that these modifications are due to the growth of polymeric stress within specific regions of the flow domain. Our data fill a significant gap in the literature between the previously reported purely inertial and purely elastic flow regimes and provide a link between the two by showing how the instability mode is transformed as the fluid elasticity is varied. Our results and novel methods are relevant to understanding the mechanisms underlying industrial uses of weakly elastic fluids and also to understanding inertioelastic instabilities in more confined flows through channels with intersections and stagnation points.

The effect of mixing rates on the formation and growth of condensation aerosols in a model stagnation flow

KAUST Repository

Alshaarawi, Amjad; Bisetti, Fabrizio

2015-01-01

A steady, laminar stagnation flow configuration is adopted to investigate numerically the interaction between condensing aerosol particles and gas-phase transport across a canonical mixing layer. The mixing rates are varied by adjusting the velocity and length scales of the stagnation flow parametrically. The effect of mixing rates on particle concentration, polydispersity, and mean droplet diameter is explored and discussed. This numerical study reveals a complex response of the aerosol to varying flow times. Depending on the flow time, the variation of the particle concentration in response to varying mixing rates falls into one of the two regimes. For fast mixing rates, the number density and volume fraction of the condensing particles increase with residence time (nucleation regime). On the contrary, for low mixing rates, number density decreases with residence time and volume fraction reaches a plateau (condensation regime). It is shown that vapor scavenging by the aerosol phase is key to explaining the transition between these two regimes. The results reported here are general and illustrate genuine features of the evolution of aerosols forming by condensation of supersaturated vapor from heat and mass transport across mixing layers.

The effect of mixing rates on the formation and growth of condensation aerosols in a model stagnation flow

KAUST Repository

Alshaarawi, Amjad

2015-03-01

A steady, laminar stagnation flow configuration is adopted to investigate numerically the interaction between condensing aerosol particles and gas-phase transport across a canonical mixing layer. The mixing rates are varied by adjusting the velocity and length scales of the stagnation flow parametrically. The effect of mixing rates on particle concentration, polydispersity, and mean droplet diameter is explored and discussed. This numerical study reveals a complex response of the aerosol to varying flow times. Depending on the flow time, the variation of the particle concentration in response to varying mixing rates falls into one of the two regimes. For fast mixing rates, the number density and volume fraction of the condensing particles increase with residence time (nucleation regime). On the contrary, for low mixing rates, number density decreases with residence time and volume fraction reaches a plateau (condensation regime). It is shown that vapor scavenging by the aerosol phase is key to explaining the transition between these two regimes. The results reported here are general and illustrate genuine features of the evolution of aerosols forming by condensation of supersaturated vapor from heat and mass transport across mixing layers.

Application of turbulence modeling to predict surface heat transfer in stagnation flow region of circular cylinder

Science.gov (United States)

Wang, Chi R.; Yeh, Frederick C.

1987-01-01

A theoretical analysis and numerical calculations for the turbulent flow field and for the effect of free-stream turbulence on the surface heat transfer rate of a stagnation flow are presented. The emphasis is on the modeling of turbulence and its augmentation of surface heat transfer rate. The flow field considered is the region near the forward stagnation point of a circular cylinder in a uniform turbulent mean flow. The free stream is steady and incompressible with a Reynolds number of the order of 10 to the 5th power and turbulence intensity of less than 5 percent. For this analysis, the flow field is divided into three regions: (1) a uniform free-stream region where the turbulence is homogeneous and isotropic; (2) an external viscid flow region where the turbulence is distorted by the variation of the mean flow velocity; and, (3) an anisotropic turbulent boundary layer region over the cylinder surface. The turbulence modeling techniques used are the kappa-epsilon two-equation model in the external flow region and the time-averaged turbulence transport equation in the boundary layer region. The turbulence double correlations, the mean velocity, and the mean temperature within the boundary layer are solved numerically from the transport equations. The surface heat transfer rate is calculated as functions of the free-stream turbulence longitudinal microlength scale, the turbulence intensity, and the Reynolds number.

IGF-1 deficiency in a critical period early in life influences the vascular aging phenotype in mice by altering miRNA-mediated post-transcriptional gene regulation: implications for the developmental origins of health and disease hypothesis.

Science.gov (United States)

Tarantini, Stefano; Giles, Cory B; Wren, Jonathan D; Ashpole, Nicole M; Valcarcel-Ares, M Noa; Wei, Jeanne Y; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

2016-08-01

Epidemiological findings support the concept of Developmental Origins of Health and Disease, suggesting that early-life hormonal influences during a sensitive period of development have a fundamental impact on vascular health later in life. The endocrine changes that occur during development are highly conserved across mammalian species and include dramatic increases in circulating IGF-1 levels during adolescence. The present study was designed to characterize the effect of developmental IGF-1 deficiency on the vascular aging phenotype. To achieve that goal, early-onset endocrine IGF-1 deficiency was induced in mice by knockdown of IGF-1 in the liver using Cre-lox technology (Igf1 f/f mice crossed with mice expressing albumin-driven Cre recombinase). This model exhibits low-circulating IGF-1 levels during the peripubertal phase of development, which is critical for the biology of aging. Due to the emergence of miRNAs as important regulators of the vascular aging phenotype, the effect of early-life IGF-1 deficiency on miRNA expression profile in the aorta was examined in animals at 27 months of age. We found that developmental IGF-1 deficiency elicits persisting late-life changes in miRNA expression in the vasculature, which significantly differed from those in mice with adult-onset IGF-1 deficiency (TBG-Cre-AAV8-mediated knockdown of IGF-1 at 5 month of age in Igf1 f/f mice). Using a novel computational approach, we identified miRNA target genes that are co-expressed with IGF-1 and associate with aging and vascular pathophysiology. We found that among the predicted targets, the expression of multiple extracellular matrix-related genes, including collagen-encoding genes, were downregulated in mice with developmental IGF-1 deficiency. Collectively, IGF-1 deficiency during a critical period during early in life results in persistent changes in post-transcriptional miRNA-mediated control of genes critical targets for vascular health, which likely contribute to the

Botulinum Toxin A for Oral Cavity Cancer Patients: In Microsurgical Patients BTX Injections in Major Salivary Glands Temporarily Reduce Salivary Production and the Risk of Local Complications Related to Saliva Stagnation

OpenAIRE

Corradino, Bartolo; Lorenzo, Sara Di; Moschella, Francesco

2012-01-01

In patients suffering from oral cavity cancer surgical treatment is complex because it is necessary to remove carcinoma and lymph node metastasis (through a radical unilateral or bilateral neck dissection) and to reconstruct the affected area by means of free flaps. The saliva stagnation in the post-operative period is a risk factor with regard to local complications. Minor complications related to saliva stagnation (such as tissue maceration and wound dehiscence) could become major complicat...

From Parent-Child Mutuality to Security to Socialization Outcomes: Developmental Cascade toward Positive Adaptation in Preadolescence

Science.gov (United States)

Kim, Sanghag; Boldt, Lea J.; Kochanska, Grazyna

2016-01-01

A developmental cascade from positive early parent-child relationship to child security with the parent to adaptive socialization outcomes, proposed in attachment theory and often implicitly accepted but rarely formally tested, was examined in 100 mothers, fathers, and children followed from toddler age to preadolescence. Parent-child Mutually Responsive Orientation (MRO) was observed in lengthy interactions at 38, 52, 67, and 80 months; children reported their security with parents at age 8. Socialization outcomes (parent- and child-reported cooperation with parental monitoring and teacher-reported school competence) were assessed at age 10. Mediation was tested with PROCESS (Hayes, 2013). The parent-child history of MRO significantly predicted both mother-child and father-child security. For mother-child dyads, security mediated links between history of MRO and cooperation with maternal monitoring and school competence, controlling for developmental continuity of the studied constructs. For father-child dyads, the mediation effect was not evident. PMID:26258443

Stagnation and Storage of Strongly Depleted Melts in Slow-Ultraslow Spreading Oceans: Evidence from the Ligurian Tethys

Science.gov (United States)

Piccardo, Giovanni; Guarnieri, Luisa; Padovano, Matteo

2013-04-01

Our studies of Alpine-Apennine ophiolite massifs (i.e., Lanzo, Voltri, Ligurides, Corsica) show that the Jurassic Ligurian Tethys oceanic basin was a slow-ultraslow spreading basin, characterized by the exposures on the seafloor of mantle peridotites with extreme compositional variability. The large majority of these peridotites are made of depleted spinel harzburgites and plagioclase peridotites. The former are interpreted as reactive peridotites formed by the reactive percolation of under-saturated, strongly trace element depleted asthenospheric melts migrated by porous flow through the mantle lithosphere. The latter are considered as refertilized peridotites formed by peridotite impregnation by percolated silica-saturated, strongly trace element depleted melts. Strongly depleted melts were produced as low-degrees, single melt increments by near fractional melting of the passively upwelling asthenosphere during the rifting stage of the basin. They escaped single melt increment aggregation, migrated isolated through the mantle lithosphere by reactive porous or channeled flow before oceanic opening, and were transformed into silica-saturated derivative liquids that underwent entrapment and stagnation in the shallow mantle lithosphere forming plagioclase-enriched peridotites. Widespread small bodies of strongly depleted gabbro-norites testify for the local coalescence of these derivative liquids. These melts never reached the surface (i.e., the hidden magmatism), since lavas with their composition have never been found in the basin. Subsequently, aggregated MORB melts upwelled within replacive dunite channels (as evidenced by composition of magmatic clinopyroxenes in dunites), intruded at shallow levels as olivine gabbro bodies and extruded as basaltic lavas, to form the crustal rocks of the oceanic lithosphere (i.e., the oceanic magmatism). Km-scale bodies of MORB olivine gabbros were intruded into the plagioclase-enriched peridotites, which were formed in the

New optical method for heat flux measurements in stagnation point laminar methane/air flames and hydrogen/methane/air flames using thermographic phosphors

Energy Technology Data Exchange (ETDEWEB)

Elmnefi, Mohamed Salem

2010-11-24

In the present study, a new optical method was implemented to study the heat transfer from flat stagnation point flames which can be regarded as one-dimensional in the central part. Premixed methane-air flames and hydrogen-methane-air flames were investigated. The effects of burner-to-plate distance and the fresh gas mixture velocity on heat transfer were examined. Experiments were performed using light induced phosphorescence from thermographic phosphors to study the wall temperatures and heat fluxes of nearly one-dimensional flat premixed flames impinging upward normally on a horizontal water cooled circular flat plate. The investigated flames were stoichiometric, lean and rich laminar methane/air flames with different equivalence ratios of {phi} =1, {phi} = 0.75 and {phi} = 1.25 and stoichiometric laminar hydrogen/methane/air flames. Mixtures of air with 10, 25, 50 and 75 % hydrogen in methane (CH{sub 4}) as well as a pure hydrogen flames at ambient pressure were investigated. The central part of this plate was an alumina ceramic plate coated from both sides with chromium doped alumina (ruby) and excited with a Nd:YAG laser or a green light emitting diode (LED) array to measure the wall temperature from both sides and thus the heat flux rate from the flame. The outlet velocity of the gases was varied from 0.1 m/s to 1.2 m/s. The burner to plate distance ranged from 0.5 to 2 times the burner exit diameter (d = 30 mm).The accuracy of the method was evaluated. The measured heat flux indicate the change of the flame stabilization mechanism from a burner stabilized to a stagnation plate stabilized flame. The results were compared to modeling results of a one dimensional stagnation point flow, with a detailed reaction mechanism. In order to prove the model, also measured gas phase temperatures by OH LIF for a stoichiometric stagnation point flame were discussed. It turns out that the flame stabilization mechanism and with it the heat fluxes change from low to high

Linear stability analysis of laminar flow near a stagnation point in the slip flow regime

Science.gov (United States)

Essaghir, E.; Oubarra, A.; Lahjomri, J.

2017-12-01

The aim of the present contribution is to analyze the effect of slip parameter on the stability of a laminar incompressible flow near a stagnation point in the slip flow regime. The analysis is based on the traditional normal mode approach and assumes parallel flow approximation. The Orr-Sommerfeld equation that governs the infinitesimal disturbance of stream function imposed to the steady main flow, which is an exact solution of the Navier-Stokes equation satisfying slip boundary conditions, is obtained by using the powerful spectral Chebyshev collocation method. The results of the effect of slip parameter K on the hydrodynamic characteristics of the base flow, namely the velocity profile, the shear stress profile, the boundary layer, displacement and momentum thicknesses are illustrated and discussed. The numerical data for these characteristics, as well as those of the eigenvalues and the corresponding wave numbers recover the results of the special case of no-slip boundary conditions. They are found to be in good agreement with previous numerical calculations. The effects of slip parameter on the neutral curves of stability, for two-dimensional disturbances in the Reynolds-wave number plane, are then obtained for the first time in the slip flow regime for stagnation point flow. Furthermore, the evolution of the critical Reynolds number against the slip parameter is established. The results show that the critical Reynolds number for instability is significantly increased with the slip parameter and the flow turn out to be more stable when the effect of rarefaction becomes important.

[Comparative analysis on the biological basis of blood stasis syndrome induced by qi-stagnation and qi-deficiency in patients with unstable angina pectoris].

Science.gov (United States)

Ren, Jian-xun; Liu, Jian-xun; Lin, Cheng-ren

2010-04-01

To comparatively analyse the objective characteristics of different syndrome types of qi-disturbance-induced blood stasis syndrome (QDBS) in the pathogenetic evolution of unstable angina coronary heart disease (UA-CHD). Seventy-eight patients with UA-CHD of QDBS were differentiated into 2 groups: 55 in the qi-deficiency-induced blood-stasis syndrome group (A) and 23 in the qi-stagnation-induced blood-stasis syndrome group (B). The comparative analysis on them was carried out through comparing their blood pressure, glucose and lipid metabolisms, coagulation function, thyroid function and inflammation reaction changes, etc. In the pathogenetic process of qi-disturbance induced blood stasis, the initiating age, levels of HbA1c, TSH, PT and APTT between the two groups were significantly different (P emotional stress is possibly the essence of qi-stagnation induced blood stasis syndrome.

Neurotoxicity of developmental hypothyroxinemia and hypothyroidism in rats: Impairments of long-term potentiation are mediated by phosphatidylinositol 3-kinase signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi; Wei, Wei; Wang, Yuan; Dong, Jing; Song, Binbin; Min, Hui [Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang (China); Teng, Weiping, E-mail: twpendocrine@yahoo.com.cn [Liaoning Provincial Key Laboratory of Endocrine Diseases, the First Hospital of China Medical University, Shenyang (China); Chen, Jie, E-mail: chenjie@mail.cmu.edu.cn [Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang (China)

2013-09-01

Neurotoxicity of iodine deficiency-induced hypothyroidism during developmental period results in serious impairments of brain function, such as learning and memory. These impairments are largely irreversible, and the underlying mechanisms remain unclear. In addition to hypothyroidism, iodine deficiency may cause hypothyroxinemia, a relatively subtle form of thyroid hormone deficiency. Neurotoxicity of developmental hypothyroxinemia also potentially impairs learning and memory. However, more direct evidence of the associations between developmental hypothyroxinemia and impairments of learning and memory should be provided, and the underlying mechanisms remain to be elucidated. Thus, in the present study, we investigated the effects of developmental hypothyroxinemia and hypothyroidism on long-term potentiation (LTP), a widely accepted cellular model of learning and memory, in the hippocampal CA1 region. The activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway – a pathway closely associated with synaptic plasticity and learning and memory – was also investigated. Wistar rats were treated with iodine deficient diet or methimazole (MMZ) to induce developmental hypothyroxinemia or hypothyroidism. The results showed that developmental hypothyroxinemia caused by mild iodine deficiency and developmental hypothyroidism caused by severe iodine deficiency or MMZ significantly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Decreased activation of the PI3K signaling pathway was also observed in rats subjected to developmental hypothyroxinemia or hypothyroidism. Our results may support the hypothesis that neurotoxicity of both developmental hypothyroxinemia and hypothyroidism causes damages to learning and memory. Our results also suggest that decreased activation of the PI3K signaling pathway may contribute to impairments of LTP caused by neurotoxicity of both developmental hypothyroxinemia and

Neurotoxicity of developmental hypothyroxinemia and hypothyroidism in rats: Impairments of long-term potentiation are mediated by phosphatidylinositol 3-kinase signaling pathway

International Nuclear Information System (INIS)

Wang, Yi; Wei, Wei; Wang, Yuan; Dong, Jing; Song, Binbin; Min, Hui; Teng, Weiping; Chen, Jie

2013-01-01

Neurotoxicity of iodine deficiency-induced hypothyroidism during developmental period results in serious impairments of brain function, such as learning and memory. These impairments are largely irreversible, and the underlying mechanisms remain unclear. In addition to hypothyroidism, iodine deficiency may cause hypothyroxinemia, a relatively subtle form of thyroid hormone deficiency. Neurotoxicity of developmental hypothyroxinemia also potentially impairs learning and memory. However, more direct evidence of the associations between developmental hypothyroxinemia and impairments of learning and memory should be provided, and the underlying mechanisms remain to be elucidated. Thus, in the present study, we investigated the effects of developmental hypothyroxinemia and hypothyroidism on long-term potentiation (LTP), a widely accepted cellular model of learning and memory, in the hippocampal CA1 region. The activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway – a pathway closely associated with synaptic plasticity and learning and memory – was also investigated. Wistar rats were treated with iodine deficient diet or methimazole (MMZ) to induce developmental hypothyroxinemia or hypothyroidism. The results showed that developmental hypothyroxinemia caused by mild iodine deficiency and developmental hypothyroidism caused by severe iodine deficiency or MMZ significantly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Decreased activation of the PI3K signaling pathway was also observed in rats subjected to developmental hypothyroxinemia or hypothyroidism. Our results may support the hypothesis that neurotoxicity of both developmental hypothyroxinemia and hypothyroidism causes damages to learning and memory. Our results also suggest that decreased activation of the PI3K signaling pathway may contribute to impairments of LTP caused by neurotoxicity of both developmental hypothyroxinemia and

Constructivist developmental theory is needed in developmental neuroscience

Science.gov (United States)

Arsalidou, Marie; Pascual-Leone, Juan

2016-12-01

Neuroscience techniques provide an open window previously unavailable to the origin of thoughts and actions in children. Developmental cognitive neuroscience is booming, and knowledge from human brain mapping is finding its way into education and pediatric practice. Promises of application in developmental cognitive neuroscience rests however on better theory-guided data interpretation. Massive amounts of neuroimaging data from children are being processed, yet published studies often do not frame their work within developmental models—in detriment, we believe, to progress in this field. Here we describe some core challenges in interpreting the data from developmental cognitive neuroscience, and advocate the use of constructivist developmental theories of human cognition with a neuroscience interpretation.

Thermophysical analysis for three-dimensional MHD stagnation-point flow of nano-material influenced by an exponential stretching surface

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Fiaz Ur Rehman

2018-03-01

Full Text Available In the present paper a theoretical investigation is performed to analyze heat and mass transport enhancement of water-based nanofluid for three dimensional (3D MHD stagnation-point flow caused by an exponentially stretched surface. Water is considered as a base fluid. There are three (3 types of nanoparticles considered in this study namely, CuO (Copper oxide, Fe3O4 (Magnetite, and Al2O3 (Alumina are considered along with water. In this problem we invoked the boundary layer phenomena and suitable similarity transformation, as a result our three dimensional non-linear equations of describing current problem are transmuted into nonlinear and non-homogeneous differential equations involving ordinary derivatives. We solved the final equations by applying homotopy analysis technique. Influential outcomes of aggressing parameters involved in this study, effecting profiles of temperature field and velocity are explained in detail. Graphical results of involved parameters appearing in considered nanofluid are presented separately. It is worth mentioning that Skin-friction along x and y-direction is maximum for Copper oxide-water nanofluid and minimum for Alumina-water nanofluid. Result for local Nusselt number is maximum for Copper oxide-water nanofluid and is minimum for magnetite-water nanofluid. Keywords: Heat transfer, Nanofluids, Stagnation-point flow, Three-dimensional flow, Nano particles, Boundary layer

Predator mediated selection and the impact of developmental stage on viability in wood frog tadpoles (Rana sylvatica

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Calsbeek Ryan

2011-12-01

Full Text Available Abstract Background Complex life histories require adaptation of a single organism for multiple ecological niches. Transitions between life stages, however, may expose individuals to an increased risk of mortality, as the process of metamorphosis typically includes developmental stages that function relatively poorly in both the pre- and post-metamorphic habitat. We studied predator-mediated selection on tadpoles of the wood frog, Rana sylvatica, to identify this hypothesized period of differential predation risk and estimate its ontogenetic onset. We reared tadpoles in replicated mesocosms in the presence of the larval odonate Anax junius, a known tadpole predator. Results The probability of tadpole survival increased with increasing age and size, but declined steeply at the point in development where hind limbs began to erupt from the body wall. Selection gradient analyses indicate that natural selection favored tadpoles with short, deep tail fins. Tadpoles resorb their tails as they progress toward metamorphosis, which may have led to the observed decrease in survivorship. Path models revealed that selection acted directly on tail morphology, rather than through its indirect influence on swimming performance. Conclusions This is consistent with the hypothesis that tail morphology influences predation rates by reducing the probability a predator strikes the head or body.

A numerical study for off-centered stagnation flow towards a rotating disc

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M. Heydari

2015-09-01

Full Text Available In this investigation, a semi-numerical method based on Bernstein polynomials for solving off-centered stagnation flow towards a rotating disc is introduced. This method expands the desired solutions in terms of a set of Bernstein polynomials over a closed interval and then makes use of the tau method to determine the expansion coefficients to construct approximate solutions. This method can satisfy boundary conditions at infinity. The properties of Bernstein polynomials are presented and are utilized to reduce the solution of governing nonlinear equations and their associated boundary conditions to the solution of algebraic equations. Graphical results are presented to investigate the influence of the rotation ratio α on the radial velocity, azimuthal velocity and the induced velocities. A comparative study with the previous results of viscous fluid flow in the literature is made.

Mapping Developmental Precursors of Cyber-Aggression: Trajectories of Risk Predict Perpetration and Victimization

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Modecki, Kathryn L.; Barber, Bonnie L.; Vernon, Lynnette

2013-01-01

Technologically mediated contexts are social arenas in which adolescents can be both perpetrators and victims of aggression. Yet, there remains little understanding of the developmental etiology of cyber aggression, itself, as experienced by either perpetrators or victims. The current study examines 3-year latent within-person trajectories of…

Melting heat transfer in boundary layer stagnation-point flow towards a stretching/shrinking sheet

International Nuclear Information System (INIS)

Bachok, Norfifah; Ishak, Anuar; Pop, Ioan

2010-01-01

An analysis is carried out to study the steady two-dimensional stagnation-point flow and heat transfer from a warm, laminar liquid flow to a melting stretching/shrinking sheet. The governing partial differential equations are converted into ordinary differential equations by similarity transformation, before being solved numerically using the Runge-Kutta-Fehlberg method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented for different values of the governing parameters. Effects of the melting parameter, stretching/shrinking parameter and Prandtl number on the flow and heat transfer characteristics are thoroughly examined. Different from a stretching sheet, it is found that the solutions for a shrinking sheet are non-unique.

Assessment of Fuel Analysis Methodology and Fission Product Release for 37-Element Fuel by Using the Latest IST Codes during Stagnation Feeder Break in CANDU

International Nuclear Information System (INIS)

Park, Joo Hwan; Jung, Jong Yeob

2009-09-01

Feeder break accident is regarded as one of the design basis accident in CANDU reactor which results in a fuel failure. For a particular range of inlet feeder break sizes, the flow in the channel is reduced sufficiently that the fuel and fuel channel integrity can be significantly affected to have damage in the affected channel, while the remainder of the core remains adequately cooled. The flow in the downstream channel can be more or less stagnated due to a balance between pressure at the break on the upstream side and the reverse driving pressure between the break and the downstream end. In the extreme, this can lead to rapid fuel heatup and fuel damage and failure of the fuel channel similar to that associated with a severe channel flow blockage. Such an inlet feeder break scenario is called a stagnation break. In this report, the fuel analysis methodology and the assessment results of fission product inventory and release during the stagnation feeder break are described for conservatively assumed limiting channel. The accident was assumed to be occurred in the refurbished Wolsong unit 1 and the latest safety codes were used in the analysis. Fission product inventories during the steady state were calculated by using ELESTRES-IST 1.2 code. The whole analysis process was carried out by a script file which was programmed by Perl language. The perl script file was programmed to make all ELESTRES input files for each bundle and each ring based on the given power-burnup history and thermal-hydraulic conditions of the limiting channel and to perform the fuel analysis automatically. The fission product release during the transient period of stagnation feeder break was evaluated by applying Gehl model. The amounts of each isotope's release are conservatively evaluated for additional 2 seconds after channel failure. The calculated fission product releases are provided to the following dose assessment as a source term

Biological nitrate transport in sediments on the Peruvian margin mitigates benthic sulfide emissions and drives pelagic N loss during stagnation events

Science.gov (United States)

Dale, A. W.; Sommer, S.; Lomnitz, U.; Bourbonnais, A.; Wallmann, K.

2016-06-01

Benthic N cycling in the Peruvian oxygen minimum zone (OMZ) was investigated at ten stations along 12 °S from the middle shelf (74 m) to the upper slope (1024 m) using in situ flux measurements, sediment biogeochemistry and modeling. Middle shelf sediments were covered by mats of the filamentous bacteria Thioploca spp. and contained a large 'hidden' pool of nitrate that was not detectable in the porewater. This was attributed to a biological nitrate reservoir stored within the bacteria to oxidize sulfide during 'dissimilatory nitrate reduction to ammonium' (DNRA). The extremely high rates of DNRA on the shelf (15.6 mmol m-2 d-1 of N), determined using an empirical steady-state model, could easily supply all the ammonium requirements for anammox in the water column. The model further showed that denitrification by foraminifera may account for 90% of N2 production at the lower edge of the OMZ. At the time of sampling, dissolved oxygen was below detection limit down to 400 m and the water body overlying the shelf had stagnated, resulting in complete depletion of nitrate and nitrite. A decrease in the biological nitrate pool was observed on the shelf during fieldwork concomitant with a rise in porewater sulfide levels in surface sediments to 2 mM. Using a non-steady state model to simulate this natural anoxia experiment, these observations were shown to be consistent with Thioploca surviving on a dwindling intracellular nitrate reservoir to survive the stagnation period. The model shows that sediments hosting Thioploca are able to maintain high ammonium fluxes for many weeks following stagnation, potentially sustaining pelagic N loss by anammox. In contrast, sulfide emissions remain low, reducing the economic risk to the Peruvian fishery by toxic sulfide plume development.

Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents.

Science.gov (United States)

Gilbert, Scott F; Bosch, Thomas C G; Ledón-Rettig, Cristina

2015-10-01

The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.

Transcription regulation by the Mediator complex.

Science.gov (United States)

Soutourina, Julie

2018-04-01

Alterations in the regulation of gene expression are frequently associated with developmental diseases or cancer. Transcription activation is a key phenomenon in the regulation of gene expression. In all eukaryotes, mediator of RNA polymerase II transcription (Mediator), a large complex with modular organization, is generally required for transcription by RNA polymerase II, and it regulates various steps of this process. The main function of Mediator is to transduce signals from the transcription activators bound to enhancer regions to the transcription machinery, which is assembled at promoters as the preinitiation complex (PIC) to control transcription initiation. Recent functional studies of Mediator with the use of structural biology approaches and functional genomics have revealed new insights into Mediator activity and its regulation during transcription initiation, including how Mediator is recruited to transcription regulatory regions and how it interacts and cooperates with PIC components to assist in PIC assembly. Novel roles of Mediator in the control of gene expression have also been revealed by showing its connection to the nuclear pore and linking Mediator to the regulation of gene positioning in the nuclear space. Clear links between Mediator subunits and disease have also encouraged studies to explore targeting of this complex as a potential therapeutic approach in cancer and fungal infections.

Role Overload, Role Self Distance, Role Stagnation as Determinants of Job Satisfaction and Turnover Intention in Banking Sector

OpenAIRE

Kunte, Monica; Gupta, Priya; Bhattacharya, Sonali; Neelam, Netra

2017-01-01

Purpose: This study examined the relationship of the organizational role stress: Role overload, role self-distance, and role stagnation with job satisfaction and turnover intention with a sample of banking employees in India. Methodology: In this research, we used the RODS scale developed by Prohit and Pareek (2010) for measuring occupational role scale. The reliability of the scale came out to be 0.71. Findings: The majority of employees of all ranks, in both private and public sector banks,...

Investigation of Three-Dimensional Axisymmetric Unsteady Stagnation-Point Flow and Heat Transfer Impinging on an Accelerated Flat Plate

OpenAIRE

ali shokrgozar abbasi; Asghar Baradaran Rahimi; Hamidreza Mozayeni

2016-01-01

General formulation and solution of Navier-Stokes and energy equations are sought in the study of threedimensional axisymmetric unsteady stagnation-point flow and heat transfer impinging on a flat plate when the plate is moving with variable velocity and acceleration towards the main stream or away from it. As an application, among others, this accelerated plate can be assumed as a solidification front which is being formed with variable velocity. An external fluid, along z - directi...

Hall effect upon small wavelength kink instabilities near an elliptic magnetic stagnation line

International Nuclear Information System (INIS)

Spies, G.O.; Faghihi, M.

1985-12-01

To explore the question whether the Hall effect removes the unphysical feature of ideal magnetohydrodynamics of predicting unstable small wavelenght kinks near any elliptic magnetic stagnation line, a spectral analysis is performed of the motion of an incompressible plasma about cylindrical Z-pinch equilibria with circular sections. The eigenvalue loci in the complex frequency plane are derived for the equilibrium with constant current density. These show that every particular mode becomes stable as the Hall parameter exceeds a critical value. However, this critical value is a decreasing function of the ideal growth rate and has a pole at the origin, implying that there always remains an infinite reservoir of slowly growing instabilities. Correspondingly, for equilibiria with arbitrary current distributions, the stability criterion is unaffected by the Hall term. (author)

Acceptance of Disability and Hwa-Byung among Korean Mothers of Children with Developmental Disabilities

Science.gov (United States)

Kim, Eunha; Hwang, Jowon; Park, Sukyoung

2018-01-01

This study examined how child problem behaviour could be related to maternal Hwa-Byung (HB; Korean culture syndrome, meaning "anger illness") among Korean mothers of children with developmental disabilities. Acceptance of disabilities and parenting stress were tested as mediators for the relationship between child problem behaviour and…

Glucocorticoids as mediators of developmental programming effects.

Science.gov (United States)

Khulan, Batbayar; Drake, Amanda J

2012-10-01

Epidemiological evidence suggests that exposure to an adverse environment in early life is associated with an increased risk of cardio-metabolic and behavioral disorders in adulthood, a phenomenon termed 'early life programming'. One major hypothesis for early life programming is fetal glucocorticoid overexposure. In animal studies, prenatal glucocorticoid excess as a consequence of maternal stress or through exogenous administration to the mother or fetus is associated with programming effects on cardiovascular and metabolic systems and on the brain. These effects can be transmitted to subsequent generations. Studies in humans provide some evidence that prenatal glucocorticoid exposure may exert similar programming effects on glucose/insulin homeostasis, blood pressure and neurodevelopment. The mechanisms by which glucocorticoids mediate these effects are unclear but may include a role for epigenetic modifications. This review discusses the evidence for glucocorticoid programming in animal models and in humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adaptive developmental plasticity: Compartmentalized responses to environmental cues and corresponding internal signals provide phenotypic flexibility

NARCIS (Netherlands)

Mateus, A.R.A.; Marques-Pita, M.; Oostra, V.; Lafuente, E.; Brakefield, P.M.; Zwaan, B.J.; Beldade, P.

2014-01-01

Background The environmental regulation of development can result in the production of distinct phenotypes from the same genotype and provide the means for organisms to cope with environmental heterogeneity. The effect of the environment on developmental outcomes is typically mediated by hormonal

Gender and developmental differences in exercise beliefs among youth and prediction of their exercise behavior.

Science.gov (United States)

Garcia, A W; Broda, M A; Frenn, M; Coviak, C; Pender, N J; Ronis, D L

1995-08-01

This study examined gender and developmental differences in exercise-related beliefs and exercise behaviors of 286 racially diverse youth and explored factors predictive of exercise. Compared to males, females reported less prior and current exercise, lower self-esteem, poorer health status, and lower exercise self-schema. Adolescents, in contrast to pre-adolescents, reported less social support for exercise and fewer exercise role models. In a path model, gender, the benefits/barriers differential, and access to exercise facilities and programs directly predicted exercise. Effects of grade, perceived health status, exercise self-efficacy, social support for exercise, and social norms for exercise on exercise behavior, were mediated through the benefits/barriers differential. Effect of race on exercise was mediated by access to exercise facilities and programs. Continued exploration of gender and developmental differences in variables influencing physical activity can yield valuable information for tailoring exercise promotion interventions to the unique needs of youth.

Stagnating Jatropha Biofuel Development in Southwest China: An Institutional Approach

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Jia Li

2014-05-01

Full Text Available Biodiesel from jatropha has been considered as a promising alternative to fossil fuels for some time. Consequently, China started promoting jatropha as one of the options to meet its ever-increasing energy consumption, and the Chinese biodiesel industry also gained interest. However, the excitement of the biofuel industry in jatropha faded after it did not bring about the expected results. This article investigates the stagnation in jatropha development and production for biodiesel in China, using two detailed case studies of jatropha biofuel production in southeast China. It is found that the underdeveloped biodiesel policy and regulation, such as a rather late formulation of standards for biodiesel (especially the B5 and the absence of mandatory targets, is an important reason for hampering jatropha development. Besides that, lack of financial support undermined sustained jatropha planting at the farm level and lack of sustained commitment from state-owned enterprises or private companies over a long time span further contributed to jatropha project’s failure. Better implementation of the rule of law, mandatory blending requirements, hazard insurance, as well as continuous financial support, might improve the continuation of jatropha plantation schemes.

Stagnation point flow and heat transfer over a nonlinear shrinking sheet with slip effects

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N.F. Fauzi

2015-12-01

Full Text Available In this paper, an investigation is performed to analyze the effects of the slip parameters A and B on the steady stagnation-point flow and heat transfer due to a shrinking sheet in a viscous and incompressible fluid. Using similarity transformations, the governing boundary layer equations are transformed into the nonlinear ordinary (similar differential equations. The transformed equations are solved numerically using the shooting method. The dual solutions for velocity and temperature distribution exist for certain values of the positive constant velocity and temperature slip parameters. Likewise, a stability analysis has been performed to find the nature of the dual solutions. The velocity slip will delay the boundary layer separation whereas the temperature slip does not affect the boundary layer separation.

Mediator: A key regulator of plant development.

Science.gov (United States)

Buendía-Monreal, Manuel; Gillmor, C Stewart

2016-11-01

Mediator is a multiprotein complex that regulates transcription at the level of RNA pol II assembly, as well as through regulation of chromatin architecture, RNA processing and recruitment of epigenetic marks. Though its modular structure is conserved in eukaryotes, its subunit composition has diverged during evolution and varies in response to environmental and tissue-specific inputs, suggesting different functions for each subunit and/or Mediator conformation. In animals, Mediator has been implicated in the control of differentiation and morphogenesis through modulation of numerous signaling pathways. In plants, studies have revealed roles for Mediator in regulation of cell division, cell fate and organogenesis, as well as developmental timing and hormone responses. We begin this review with an overview of biochemical mechanisms of yeast and animal Mediator that are likely to be conserved in all eukaryotes, as well as a brief discussion of the role of Mediator in animal development. We then present a comprehensive review of studies of the role of Mediator in plant development. Finally, we point to important questions for future research on the role of Mediator as a master coordinator of development. Copyright © 2016 Elsevier Inc. All rights reserved.

Different AMPA receptor subtypes mediate the distinct kinetic components of a biphasic EPSC in hippocampal interneurons

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Todd eStincic

2015-05-01

Full Text Available CA1 hippocampal interneurons at the border between stratum radiatum and stratum lacunosum-moleculare have AMPA receptor (AMPAR-mediated excitatory postsynaptic currents (EPSCs that consist of two distinct phases: a typical fast component (FC, and a highly unusual slow component (SC that persists for hundreds of milliseconds. To determine whether these kinetically distinct components of the EPSC are mediated by distinct AMPAR subpopulations, we examined the relative contributions of GluA2-containing and –lacking AMPARs to the SC. GluA2-containing AMPARs mediated the majority of the FC whereas GluA2-lacking AMPARs preferentially generated the SC. When glutamate uptake through the glial glutamate transporter EAAT1 was inhibited, spill over-mediated AMPAR activation recruited an even slower third kinetic component that persisted for several seconds; however, this spillover-mediated current was mediated predominantly by GluA2-containing AMPARs and therefore was clearly distinct from the SC when uptake is intact. Thus, different AMPAR subpopulations that vary in GluA2 content mediate the distinct components of the AMPAR EPSC. The SC is developmentally downregulated in mice, declining after the second postnatal week. This downregulation affects both GluA2-containing and GluA2-lacking AMPARs mediating the SC, and is not accompanied by developmental changes in the GluA2 content of AMPARs underlying the FC. Thus, the downregulation of the SC appears to be independent of synaptic GluA2 expression, suggesting the involvement of another AMPAR subunit or an auxiliary protein. Our results therefore identify GluA2-dependent and GluA2-independent determinants of the SC: GluA2-lacking AMPARs preferentially contribute to the SC, while the developmental downregulation of the SC is independent of GluA2 content.

Cultural Mediation. The Usefulness of Selected Concepts of Developmental Psychology for Coaching and Mentoring Relations

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Barbara Smorczewska

2013-09-01

Full Text Available Some developmental psychological concepts, such as L. S. Vygotsky’s zone of proximal development or H. R. Schaffer’s joint involvement episodes, gave a new perspective in perceiving the process of teaching and development, by providing very detailed characteristics of the situation of acquiring competence in social relations. The mentioned concepts are based on a belief in the developmental potential of humans, and they perceive teaching as future-oriented. These assumptions are also characteristic for coaching and mentoring which are nowadays becoming more and more popular forms of development in work places; hence an attempt to find some analogy between them. The prepared comparison contributes to extending the theoretical bases of “development cooperation relations,” as coaching and mentoring are jointly referred to.

Optimism and benefit finding in parents of children with developmental disabilities: The role of positive reappraisal and social support.

Science.gov (United States)

Slattery, Éadaoin; McMahon, Jennifer; Gallagher, Stephen

2017-06-01

Researchers have consistently documented the relationship between optimism and benefit finding; however, there is a dearth of research on the psychological mechanisms mediating their association. This cross-sectional study sought to elucidate the mediating role of positive reappraisal and social support in the optimism-benefit finding relationship in parents caring for children with developmental disabilities by testing a parallel multiple mediation model. One hundred and forty-six parents caring for children with developmental disabilities completed an online survey assessing optimism, positive reappraisal, social support and benefit finding. Optimism was not directly related to benefit finding but rather influenced it indirectly through positive reappraisal and social support. Specifically, higher levels of optimism predicted greater positive reappraisal and social support, which in turn led to greater benefit finding in parents. These results underscore the importance of targeting parents' perceptions of benefits through both positive reappraisal and social support in order to help them cope with the demands of the caregiving context. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of developmental factors in hypothalamic function

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Jakob eBiran

2015-04-01

Full Text Available The hypothalamus is a brain region which regulates homeostasis by mediating endocrine, autonomic and behavioral functions. It is comprised of several nuclei containing distinct neuronal populations producing neuropeptides and neurotransmitters that regulate fundamental body functions including temperature and metabolic rate, thirst and hunger, sexual behavior and reproduction, circadian rhythm, and emotional responses. The identity, number and connectivity of these neuronal populations are established during the organism’s development and are of crucial importance for normal hypothalamic function. Studies have suggested that developmental abnormalities in specific hypothalamic circuits can lead to obesity, sleep disorders, anxiety, depression and autism. At the molecular level, the development of the hypothalamus is regulated by transcription factors, secreted growth factors, neuropeptides and their receptors. Recent studies in zebrafish and mouse have demonstrated that some of these molecules maintain their expression in the adult brain and subsequently play a role in the physiological functions that are regulated by hypothalamic neurons. Here, we summarize the involvement of some of the key developmental factors in hypothalamic development and function by focusing on the mouse and zebrafish genetic model organisms.

Overcoming Stagnation in the Levels and Distribution of Child Mortality: The Case of the Philippines.

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Raoul Bermejo

Full Text Available Health-related within-country inequalities continue to be a matter of great interest and concern to both policy makers and researchers. This study aims to assess the level and the distribution of child mortality outcomes in the Philippines across geographical and socioeconomic indicators.Data on 159,130 children ever borne were analysed from five waves of the Philippine Demographic and Health Survey. Direct estimation was used to construct under-five and neonatal mortality rates for the period 1980-2013. Rate differences and ratios, and where possible, slope and relative indices of inequality were calculated to measure disparities on absolute and relative scales. Stratification was undertaken by levels of rural/urban location, island groups and household wealth.National under-five and neonatal mortality rates have shown considerable albeit differential reductions since 1980. Recently released data suggests that neonatal mortality has declined following a period of stagnation. Declines in under-five mortality have been accompanied by decreases in wealth and geography-related absolute inequalities. However, relative inequalities for the same markers have remained stable over time. For neonates, mixed evidence suggests that absolute and relative inequalities have remained stable or may have risen.In addition to continued reductions in under-five mortality, new data suggests that the Philippines have achieved success in addressing the commonly observed stagnated trend in neonatal mortality. This success has been driven by economic improvement since 2006 as well as efforts to implement a nationwide universal health care campaign. Yet, such patterns, nonetheless, accorded with persistent inequalities, particularly on a relative scale. A continued focus on addressing universal coverage, the influence of decentralisation and armed conflict, and issues along the continuum of care is advocated.

THERMOSS: a thermohydraulic model of flow stagnation in a horizontal fuel channel

International Nuclear Information System (INIS)

Gulshani, P.; Caplan, M.Z.; Spinks, N.J.

1984-01-01

Following a postulated inlet-side small break in the CANDU reactor, emergency coolant is injected to refull the horizontal fuel channels and remove the decay heat. As part of the accident analysis, the effects of loss of forced circulation during the accident are predicted. A break size exists for which, at the end of pump rundown, the break force balances the natural circulation force and the channel flow is reduced to near zero. The subcooled, stagnant channel condition is referred to as the standing-start condition. Subsequently, the channel coolant boils and stratifies. Eventually the steam flow from the channel heats up the endfitting to the saturation temperature and reaches the vertical feeder. The resulting buoyancy-induced flow then refills the channel. One dimensional, two-fluid conservation equations are solved in closed form to predict the duration of stagnation. In this calculation the channel water level is an important intermediate variable because it determines the amount of steam production

Categorization of flow conditions using Integral quantities for characterizing stagnation and recirculation

International Nuclear Information System (INIS)

Han, M.H.; Hwang, W.T.; Jeong, H.J.; Kim, E.H.

2008-01-01

This paper describes a method for categorizing an atmospheric flow condition of a site by using integral quantities for characterizing stagnation and recirculation. Authors have devised a method for categorizing flow conditions using distribution curves which represent the flow condition of the whole of Korea. It was found that the flow conditions for four nuclear power plant sites were good enough from a meteorological aspect. Among the four sites, Kori nuclear power plant site which is located at the south-eastern part of the Korean peninsular shows the best condition. Meteorological condition is the key factor for estimating the environmental effects of a nuclear facility. The devised method can be used for assessing the relative environmental risk of a nuclear facility with only meteorological data. And the devised categorization method can be used for choosing a suitable site for an industrial facility such as a nuclear power plant and a chemical complex. (author)

Parental verbal abuse and the mediating role of self-criticism in adult internalizing disorders.

Science.gov (United States)

Sachs-Ericsson, Natalie; Verona, Edelyn; Joiner, Thomas; Preacher, Kristopher J

2006-07-01

Researchers (e.g., [Gibb, B.E., 2002. Childhood maltreatment and negative cognitive styles. A quantitative and qualitative review. Clinical Psychology Review, 22 (2), 223-246]; [Rose, D.T., Abramson, L.Y., 1992. Developmental predictors of depressive cognitive styles: developmental perspectives on depression. In Cicchetti, D., Toth, S.L. (Eds.), Developmental Perspectives on Depression. Rochester symposium on developmental psychopathology, vol. 4, pp. 323-349]) have proposed that when childhood abuse is verbal (rather than sexual or physical), the child is more likely to develop a negative self-schema because the negative self-cognitions are directly supplied to the child by the abuser (e.g., "you are stupid"). In a test of this theory in adult participants, and drawing on the National Comorbidity Survey (NCS) (N=5877), we investigate the mediating role of current levels of self-criticism on the relationship between retrospective reports of parental verbal abuse, as well as sexual and physical abuse, and adult internalizing symptoms. We found self-criticism, but not dependency traits, to fully mediate the relationship between childhood verbal abuse perpetrated by parents and internalizing (depression, anxiety) symptoms. On the other hand, self-criticism was only a partial mediator of the relationship between the other types of abuse and internalizing symptoms. The NCS data is cross-sectional, which limits any firm conclusions regarding causality. While these results are suggestive that self-criticism is a mediator of the relationship between abuse and internalizing symptoms, longitudinal data are necessary to help rule out alternative explanations. Results of this study suggest that childhood abuse experiences, and in particular verbal abuse, may confer risk for internalizing disorders in part because verbal abuse influences the development of a self-critical style.

Self-Generated Magnetic Fields in Stagnation-Phase ICF Implosions

Science.gov (United States)

Walsh, Christopher; Chittenden, Jeremy; McGlinchey, Kristopher; Niasse, Nicolas

2016-10-01

3-D extended-MHD simulations of the stagnation phase of an ICF implosion are presented, showing significant self-generated magnetic fields (1000-5000T) due to the Biermann Battery effect. Perturbed hot-spots generate magnetic fields at their edges, as the extremities of hot bubbles are rapidly cooled by the surrounding low temperature fuel, giving non-parallel electron pressure and density gradients. Larger amplitude and higher mode-number perturbations lead to an increased hot-spot surface area and more heat flow, developing greater non-parallel gradients and therefore larger magnetic fields. Due to this, largely perturbed hot-spots can be affected more by magnetic fields, although the accelerated cooling associated with greater deviations from symmetry lowers magnetisation. The Nernst effect advects magnetic field down temperature gradients towards the outer region of the hot-spot, which can also lower the magnetisation of the plasma. In some regions, however, the Nernst velocity is convergent, magnetising the tips of cold fuel spikes, resulting in anisotropic heat-flow and an improvement in energy containment. Low-mode and multi-high-mode simulations are shown, with magnetisations reaching sufficiently high levels in some regions of the hot-spot to suppress thermal conduction to lower than 50% of the unmagnetised case. A quantitative analysis of how this affects the hot-spot energy balance is included.

Minimising the risk of water hammer and other problems at the beginning of stagnation of solar thermal plants - A theoretical approach

International Nuclear Information System (INIS)

Streicher, W.

2000-01-01

Solar plants are increasingly used not only for hot tap water heating but also for the assistance of space heating. These plants produce much more energy in summer than needed, which often results in stagnation. Because of stagnation-temperatures of todays selective collectors up to 200 deg. C, the collector fluid evaporates. In several plants a high noise level and a vibration of the plant during this evaporation phase is reported. This is due to the occurrence of water hammers in the system, when liquid collector fluid passes areas where the fluid was already evaporated and superheated. The remaining vapor bubbles deflate rapidly and the liquid phases collide with high velocity, which results in a rapid pressure increase. This paper describes the theory of condensate-induced water hammers and conditions of solar plants, under which this can happen. A simulation model for the evaporation phase of the collector is presented to give a deeper understanding about the influences of solar radiation, the size of the tubing, and the size of the expansion device on the process of the evaporation. Three hydraulic layouts of the collector area are discussed for there possibilities producing water hammers. (au)

Advection-diffusion model for normal grain growth and the stagnation of normal grain growth in thin films

International Nuclear Information System (INIS)

Lou, C.

2002-01-01

An advection-diffusion model has been set up to describe normal grain growth. In this model grains are divided into different groups according to their topological classes (number of sides of a grain). Topological transformations are modelled by advective and diffusive flows governed by advective and diffusive coefficients respectively, which are assumed to be proportional to topological classes. The ordinary differential equations governing self-similar time-independent grain size distribution can be derived analytically from continuity equations. It is proved that the time-independent distributions obtained by solving the ordinary differential equations have the same form as the time-dependent distributions obtained by solving the continuity equations. The advection-diffusion model is extended to describe the stagnation of normal grain growth in thin films. Grain boundary grooving prevents grain boundaries from moving, and the correlation between neighbouring grains accelerates the stagnation of normal grain growth. After introducing grain boundary grooving and the correlation between neighbouring grains into the model, the grain size distribution is close to a lognormal distribution, which is usually found in experiments. A vertex computer simulation of normal grain growth has also been carried out to make a cross comparison with the advection-diffusion model. The result from the simulation did not verify the assumption that the advective and diffusive coefficients are proportional to topological classes. Instead, we have observed that topological transformations usually occur on certain topological classes. This suggests that the advection-diffusion model can be improved by making a more realistic assumption on topological transformations. (author)

The Mediator complex and transcription regulation

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Poss, Zachary C.; Ebmeier, Christopher C.

2013-01-01

The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module. PMID:24088064

Intelligence Tests with Higher G-Loadings Show Higher Correlations with Body Symmetry: Evidence for a General Fitness Factor Mediated by Developmental Stability

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Prokosch, M.D.; Yeo, R.A.; Miller, G.F.

2005-01-01

Just as body symmetry reveals developmental stability at the morphological level, general intelligence may reveal developmental stability at the level of brain development and cognitive functioning. These two forms of developmental stability may overlap by tapping into a ''general fitness factor.'' If so, then intellectual tests with higher…

MHD stagnation point flow by a permeable stretching cylinder with Soret-Dufour effects

Institute of Scientific and Technical Information of China (English)

M Ramzan; M Farooq; T Hayat; A Alsaedi; J Cao

2015-01-01

Combined effects of Soret (thermal-diffusion) and Dufour (diffusion-thermo) in MHD stagnation point flow by a permeable stretching cylinder were studied. Analysis was examined in the presence of heat generation/absorption and chemical reaction. The laws of conservation of mass, momentum, energy and concentration are found to lead to the mathematical development of the problem. Suitable transformations were used to convert the nonlinear partial differential equations into the ordinary differential equations. The series solutions of boundary layer equations through momentum, energy and concentration equations were obtained. Convergence of the developed series solutions was discussed via plots and numerical values. The behaviors of different physical parameters on the velocity components, temperature and concentration were obtained. Numerical values of Nusselt number, skin friction and Sherwood number with different parameters were computed and analyzed. It is found that Dufour and Soret numbers result in the enhancement of temperature and concentration distributions, respectively.

I. DEVELOPMENTAL METHODOLOGY AS A CENTRAL SUBDISCIPLINE OF DEVELOPMENTAL SCIENCE.

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Card, Noel A

2017-06-01

This first chapter introduces the main goals of the monograph and previews the remaining chapters. The goals of this monograph are to provide summaries of our current understanding of advanced developmental methodologies, provide information that can advance our understanding of human development, identify shortcomings in our understanding of developmental methodology, and serve as a flagpost for organizing developmental methodology as a subdiscipline within the broader field of developmental science. The remaining chapters in this monograph address issues in design (sampling and big data), longitudinal data analysis, and issues of replication and research accumulation. The final chapter describes the history of developmental methodology, considers how the previous chapters in this monograph fit within this subdiscipline, and offers recommendations for further advancement. © 2017 The Society for Research in Child Development, Inc.

Evolution and developmental genetics of floral display-A review of progress

Institute of Scientific and Technical Information of China (English)

Qing Ma; Wenheng Zhang; Qiu-Yun (Jenny) Xiang

2017-01-01

Angiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color,size,shape,scent,arrangements,and flowering time.The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations,speciation,and angiosperm diversification.Evolutionary developmental biology (evo-devo) seeks to uncover the developmental and genetic basis underlying morphological diversification.Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution.A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g.,Arabidopsis thaliana,Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics.Gene-regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species.Meanwhile,phylogeny-based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification.Here we review the recent progress on evo-devo studies of floral display including floral symmetry,petal fusion,floral color,floral scent,and inflorescences.We also review the molecular genetic approaches applied to plant evo-devo studies and highlight the future directions of evo-devo.

Proton imaging of hohlraum plasma stagnation in inertial-confinement-fusion experiments

International Nuclear Information System (INIS)

Li, C.K.; Séguin, F.H.; Frenje, J.A.; Sinenian, N.; Rosenberg, M.J.; Manuel, M.J.-E; Rinderknecht, H.G.; Zylstra, A.B.; Petrasso, R.D.; Amendt, P.A.; Landen, O.L.; Mackinnon, A.J.; Town, R.P.J.; Wilks, S.C.; Betti, R.; Meyerhofer, D.D.; Soures, J.M.; Hund, J.; Kilkenny, J.D.; Nikroo, A.

2013-01-01

Proton radiography of the spatial structure and temporal evolution of plasma blowing off from a hohlraum wall reveals how the fill gas compresses the wall blow-off, inhibits plasma jet formation and impedes plasma stagnation in the hohlraum interior. The roles of spontaneously generated electric and magnetic fields in hohlraum dynamics and capsule implosions are demonstrated. The heat flux is shown to rapidly convect the magnetic field due to the Nernst effect, which is shown to be ∼10 times faster than convection by the plasma fluid from expanded wall blow-off (v N ∼ 10v). This leads to inhibition of heat transfer from the gas region in the laser beam paths to the surrounding cold gas, resulting in a local plasma temperature increase. The experiments show that interpenetration of the two materials (gas and wall) occurs due to the classical Rayleigh–Taylor instability as the lighter, decelerating ionized fill gas pushes against the heavier, expanding gold wall blow-off. This experiment provides physics insight into the effects of fill gas on x-ray-driven implosions, and would impact the ongoing ignition experiments at the National Ignition Facility. (paper)

Time-based prospective memory in young children-Exploring executive functions as a developmental mechanism.

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Kretschmer, Anett; Voigt, Babett; Friedrich, Sylva; Pfeiffer, Kathrin; Kliegel, Matthias

2014-01-01

The present study investigated time-based prospective memory (PM) during the transition from kindergarten/preschool to school age and applied mediation models to test the impact of executive functions (working memory, inhibitory control) and time monitoring on time-based PM development. Twenty-five preschool (age: M = 5.75, SD = 0.28) and 22 primary school children (age: M = 7.83, SD = 0.39) participated. To examine time-based PM, children had to play a computer-based driving game requiring them to drive a car on a road without hitting others cars (ongoing task) and to refill the car regularly according to a fuel gauge, which serves as clock equivalent (PM task). The level of gas that was still left in the fuel gauge was not displayed on the screen and children had to monitor it via a button press (time monitoring). Results revealed a developmental increase in time-based PM performance from preschool to school age. Applying the mediation models, only working memory was revealed to influence PM development. Neither inhibitory control alone nor the mediation paths leading from both executive functions to time monitoring could explain the link between age and time-based PM. Thus, results of the present study suggest that working memory may be one key cognitive process driving the developmental growth of time-based PM during the transition from preschool to school age.

Characterization of Mediator Complex and its Associated Proteins from Rice.

Science.gov (United States)

Samanta, Subhasis; Thakur, Jitendra Kumar

2017-01-01

The Mediator complex is a multi-protein complex that acts as a molecular bridge conveying transcriptional messages from the cis element-bound transcription factor to the RNA Polymerase II machinery. It is found in all eukaryotes including members of the plant kingdom. Increasing number of reports from plants regarding different Mediator subunits involved in a multitude of processes spanning from plant development to environmental interactions have firmly established it as a central hub of plant regulatory networks. Routine isolation of Mediator complex in a particular species is a necessity because of many reasons. First, composition of the Mediator complex varies from species to species. Second, the composition of the Mediator complex in a particular species is not static under all developmental and environmental conditions. Besides this, at times, Mediator complex is used in in vitro transcription systems. Rice, a staple food crop of the world, is used as a model monocot crop. Realizing the need of a reliable protocol for the isolation of Mediator complex from plants, we describe here the isolation of Mediator complex from rice.

The contribution of mediator-based deficiencies to age differences in associative learning.

Science.gov (United States)

Dunlosky, John; Hertzog, Christopher; Powell-Moman, Amy

2005-03-01

Production, mediational, and utilization deficiencies, which describe how strategy use may contribute to developmental trends in episodic memory, have been intensively investigated. Using a mediator report-and-retrieval method, the authors present evidence concerning the degree to which 2 previously unexplored mediator-based deficits--retrieval and decoding deficiencies--account for age deficits in learning. During study, older and younger adults were instructed to use a strategy (imagery or sentence generation) to associate words within paired associates. They also reported each mediator and later attempted to retrieve each response and the mediator produced at study. Substantial deficits occurred in mediator recall, and small differences were observed in decoding mediators. Mediator recall also accounted for a substantial proportion of the age deficits in criterion recall independently of fluid or crystallized intelligence. Discussion focuses on mediator-based deficiencies and their implications for theories of age deficits in episodic memory. Copyright 2005 APA, all rights reserved.

Thermo-diffusion effects on MHD stagnation point flow towards a stretching sheet in a nanofluid

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Umar Khan

2014-09-01

Full Text Available Thermodiffusion effects on stagnation point flow of a nanofluid towards a stretching surface with applied magnetic field is presented. Similarity transforms are applied to reduce the equations that govern the flow to a system of nonlinear ordinary differential equations. Runge-Kutta-Fehlberg method is applied to solve the system. Results are compared with existing solutions that are special cases to our problem. Concrete graphical analysis is carried out to study the effects of different emerging parameters such as stretching ratio A, magnetic influence parameter M, Prandtl number Pr, Lewis number Le, Brownian motion parameter Nb, thermophoresis parameter Nt, nanofluid Lewis number Ln, modified Dufour parameter Nd and Dufour solutal number Ld coupled with comprehensive discussions. Numerical effects of local Nusselt number, local Sherwood number and nanofluid Sherwood number are also discussed.

Disease: H00996 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H00996 Amish infantile epilepsy syndrome Amish infantile epilepsy syndrome is an a...utosomal recessive, infantile-onset symptomatic epilepsy associated with developmental stagnation and blindn...TD, Platt FM, Crosby AH ... TITLE ... Infantile-onset symptomatic epilepsy syndrome

Impairment of recollection but not familiarity in a case of developmental amnesia.

Science.gov (United States)

Brandt, Karen R; Gardiner, John M; Vargha-Khadem, Faraneh; Baddeley, Alan D; Mishkin, Mortimer

2008-01-01

In a re-examination of the recognition memory of Jon, a young adult with developmental amnesia due to perinatal hippocampal damage, we used a test procedure that provides estimates of the separate contributions to recognition of recollection and familiarity. Comparison between Jon and his controls revealed that, whereas he was unimpaired in the familiarity process, he showed abnormally low levels of recollection, supporting the view that the hippocampus mediates the latter process selectively.

Impairment of recollection but not familiarity in a case of developmental amnesia

Science.gov (United States)

Brandt, Karen R.; Gardiner, John M.; Vargha-Khadem, Faraneh; Baddeley, Alan D.; Mishkin, Mortimer

2010-01-01

In a re-examination of the recognition memory of Jon, a young adult with developmental amnesia due to perinatal hippocampal damage, we used a test procedure that provides estimates of the separate contributions to recognition of recollection and familiarity. Comparison between Jon and his controls revealed that, whereas he was unimpaired in the familiarity process, he showed abnormally low levels of recollection, supporting the view that the hippocampus mediates the latter process selectively. PMID:19090415

The Domain of Developmental Psychopathology.

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Sroufe, L. Alan; Rutter, Michael

1984-01-01

Describes how developmental psychopathology differs from related disciplines, including abnormal psychology, psychiatry, clinical child psychology, and developmental psychology. Points out propositions underlying a developmental perspective and discusses implications for research in developmental psychopathology. (Author/RH)

Excessive apoptosis and defective autophagy contribute to developmental testicular toxicity induced by fluoride

International Nuclear Information System (INIS)

Zhang, Shun; Niu, Qiang; Gao, Hui; Ma, Rulin; Lei, Rongrong; Zhang, Cheng; Xia, Tao; Li, Pei; Xu, Chunyan; Wang, Chao; Chen, Jingwen; Dong, Lixing; Zhao, Qian; Wang, Aiguo

2016-01-01

testicular damage. • The abnormal apoptosis is mediated by both Fas and mitochondrial pathways. • The autophagy defect is caused by impaired degradation but not increased formation. - Both Fas- and mitochondria-mediated apoptosis, and impaired autophagy are involved in testicular damage of rats developmentally exposed to fluoride.

Life Span Developmental Approach

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Ali Eryilmaz

2011-03-01

Full Text Available The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of individuals with respect to developmental stages. This developmental approach suggests that scientific disciplines should not explain developmental facts only with age changes. Along with aging, cognitive, biological, and socioemotional development throughout life should also be considered to provide a reasonable and acceptable context, guideposts, and reasonable expectations for the person. There are three important subjects whom life span developmental approach deals with. These are nature vs nurture, continuity vs discontinuity, and change vs stability. Researchers using life span developmental approach gather and produce knowledge on these three most important domains of individual development with their unique scientific methodology.

The search for evolutionary developmental origins of aging in zebrafish: a novel intersection of developmental and senescence biology in the zebrafish model system.

Science.gov (United States)

Kishi, Shuji

2011-09-01

Senescence may be considered the antithesis of early development, but yet there may be factors and mechanisms in common between these two phenomena during the process of aging. We investigated whether any relationship exists between the regulatory mechanisms that function in early development and in senescence using the zebrafish (Danio rerio), a small freshwater fish and a useful model animal for genetic studies. We conducted experiments to isolate zebrafish mutants expressing an apparent senescence phenotype during embryogenesis (embryonic senescence). Some of the genes we thereby identified had already been associated with cellular senescence and chronological aging in other organisms, but many had not yet been linked to these processes. Complete loss-of-function of developmentally essential genes induce embryonic (or larval) lethality, whereas it seems like their partial loss-of-function (i.e., decrease-of-function by heterozygote or hypomorphic mutations) still remains sufficient to go through the early developmental process because of its adaptive plasticity or rather heterozygote advantage. However, in some cases, such partial loss-of-function of genes compromise normal homeostasis due to haploinsufficiency later in adult life having many environmental stress challenges. By contrast, any heterozygote-advantageous genes might gain a certain benefit(s) (much more fitness) by such partial loss-of-function later in life. Physiological senescence may evolutionarily arise from both genetic and epigenetic drifts as well as from losing adaptive developmental plasticity in face of stress signals from the external environment that interacts with functions of multiple genes rather than effects of only a single gene mutation or defect. Previously uncharacterized developmental genes may thus mediate the aging process and play a pivotal role in senescence. Moreover, unexpected senescence-related genes might also be involved in the early developmental process and

Developmental psychopathology: a paradigm shift or just a relabeling?

Science.gov (United States)

Rutter, Michael

2013-11-01

Developmental psychopathology is described as a conceptual approach that involves a set of research methods that capitalize on developmental and psychopathological variations to ask questions about mechanisms and processes. Achievements are described in relation to attachment and attachment disorders, autism, schizophrenia, childhood antecedents of adult psychopathology, testing for environmental mediation of risk effects, gene-environment interplay, intellectual and language functioning, effects of mentally ill parents on the children, stress and vulnerability to depression, ethnicity and schizophrenia, and drug response. Continuities and discontinuities over the course of development are discussed in relation to attention-deficit/hyperactivity disorder, antisocial behavior, eating disorders, substance abuse and dependency, pharmacological and behavioral addictions, and a range of other disorders. Research challenges are considered in relation to spectrum concepts, the adolescent development of a female preponderance for depression, the mechanisms involved in age differences in response to drugs and to lateralized brain injury, the processing of experiences, the biological embedding of experiences, individual differences in response to environmental hazards, nature-nurture integration, and brain plasticity.

Neuromodulation and developmental contextual influences on neural and cognitive plasticity across the lifespan.

Science.gov (United States)

Li, Shu-Chen

2013-11-01

Behavioral, cognitive, and motivational development entails co-constructive interactions between the environmental and social influences from the developmental context, on the one hand, and the individual's neurobiological inheritance, on the other hand. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines and acetylcholine). Thus, the maturation and senescence of neurotransmitter systems have direct implications for lifespan development. In addition to reviewing evidence on life age differences in dopaminergic modulation and cognitive development, this brief review selectively highlights recent findings on how important influences from the developmental context, such as reward-mediated motivational processes, transgenerational stress transmission, psychosocial stress, and cognitive interventions, may, in part, exert their effects on brain and behavioral development through their effects on neuromodulatory mechanisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

A vortex ring interacting with a vortex filament and its deformation near the two-dimensional stagnation point

International Nuclear Information System (INIS)

Kiya, M.; Sato, T.

1986-01-01

In this paper the interaction between vortex filaments and vortex rings and the deformation of vortex rings near the two-dimensional stagnation point are simulated by a three-dimensional vortex method. The two problems are respectively concerned with the effect of free-stream turbulence on turbulent plane mixing layers and the production of turbulence by the vortex stretching near saddles associated with large-scale coherent structures. The authors assume that the first step to understand the free-stream turbulence effect is to study the interaction between a vortex ring and a vortex filament and that the process of deformation of a vortex ring gives us a clue to understand physical processes occurring near the saddles

Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

Energy Technology Data Exchange (ETDEWEB)

Khan, Masood [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Malik, Rabia, E-mail: rabiamalik.qau@gmail.com [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Department of Mathematics and Statistics, International Islamic University Islamabad 44000 (Pakistan); Hussain, M. [Department of Sciences and Humanities, National University of Computer and Emerging Sciences, Islamabad 44000 (Pakistan)

2016-05-15

In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

Directory of Open Access Journals (Sweden)

Masood Khan

2016-05-01

Full Text Available In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

Effect of Developmental Stimulation Program on the Developmental Measures of Toddlers

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Elahe Ghayebie

2018-04-01

Full Text Available Background: The variability in the developmental skills is reduced after the first three years of life; therefore, it is necessary to identify and manage early developmental delays. Aim: The aim of this study was to investigate the effect of developmental stimulation program on the developmental measures of the toddlers. Method: The present randomized controlled clinical trial was conducted on 31 toddlers aged 1-3 years residing at Ali Asghar Foster Care Center within 2016-2017. Developmental interventions were carried out based on the modified guidelines of West Virginia Early Learning Standards Framework for eight weeks (three 2-hour sessions a week. The interventions included a range of age- and developmental-specific activities described in the given guidelines. Child development age was measured based on motor dimensions (i.e., gross and fine and language development (i.e., receptive and expressive before and after the intervention. The data were analyzed in SPSS software (version 11 using independent t-test and Chi-square test. Results: The mean ages of the participants in the control and intervention groups were 19.9±5.5 and 20±6.02, respectively (P=0.62. The mean ages of receptive language development (P=0.003, expressive language development (P

Stagnation, circulation, and erosion of granular materials through belt conveyor sluice gate

Science.gov (United States)

Pohlman, Nicholas; Moralda, Michael; Dunne, Ryan

2013-11-01

Control of flow rates in conversion reactors for discrete materials like biomass can be achieved in belt conveyors through a combination of belt speed, hopper size, and aperture opening. As material is extracted from the bottom of the storage hopper, other material cannot achieve plug flow and therefore is restricted from exiting through a sluice-gate type opening. The excess material moves vertically from the opening causing a pile up and recirculation back along the free surface of the hopper. Experimental results obtained through high speed imaging show the position of the stagnation point as well as the rate of circulation is dependent on the mass flow rate achieved and instantaneous fill level. The movement of material into the plug flow along the belt allows verification of deposition models on erodible beds rather than rigid surfaces with artificial roughness of glued particles. Similarly, the pile-up at the exit influences the efficiency of the transport affecting the narrow energy return on investment of biomass resources. The laboratory-scale behavior can therefore be translated into industrial performance metrics for increased operational efficiency. This work is supported by the NSF REU Site Operation E-Tank under award number 1156789.

Does anger regulation mediate the discrimination-mental health link among Mexican-origin adolescents? A longitudinal mediation analysis using multilevel modeling.

Science.gov (United States)

Park, Irene J K; Wang, Lijuan; Williams, David R; Alegría, Margarita

2017-02-01

[Correction Notice: An Erratum for this article was reported in Vol 53(2) of Developmental Psychology (see record 2017-04475-001). In the article, there were several typographical errors in the Recruitment and Procedures section. The percentage of mothers who responded to survey items should have been 99.3%. Additionally, the youths surveyed at T2 and T3 should have been n 246. Accordingly, the percentage of youths surveyed in T2 and T3 should have been 91.4% and the percentage of mothers surveyed at T2 and T3 should have been 90.7%. Finally, the youths missing at T2 should have been n 23, and therefore the attrition rate for youth participants should have been 8.6. All versions of this article have been corrected.] Although prior research has consistently documented the association between racial/ethnic discrimination and poor mental health outcomes, the mechanisms that underlie this link are still unclear. The present 3-wave longitudinal study tested the mediating role of anger regulation in the discrimination-mental health link among 269 Mexican-origin adolescents ( M age = 14.1 years, SD = 1.6; 57% girls), 12 to 17 years old. Three competing anger regulation variables were tested as potential mediators: outward anger expression, anger suppression, and anger control. Longitudinal mediation analyses were conducted using multilevel modeling that disaggregated within-person effects from between-person effects. Results indicated that outward anger expression was a significant mediator; anger suppression and anger control were not significant mediators. Within a given individual, greater racial/ethnic discrimination was associated with more frequent outward anger expression. In turn, more frequent outward anger expression was associated with higher levels of anxiety and depression at a given time point. Gender, age, and nativity status were not significant moderators of the hypothesized mediation models. By identifying outward anger expression as an explanatory

Melting heat transfer in stagnation point flow of carbon nanotubes towards variable thickness surface

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T. Hayat

2016-01-01

Full Text Available This work concentrates on the mathematical modeling for stagnation point flow of nanofluids over an impermeable stretching sheet with variable thickness. Carbon nanotubes [single-wall carbon nanotubes (SWCNTs and multi-wall carbon nanotubes (MWCNTs] as the nanoparticles are utilized. Water and kerosene oil are taken as the base fluids. Heat transfer through melting effect is discussed. Transformation procedure is adapted to obtain the non-linear ordinary differential equations from the fundamental laws of mass, linear momentum and energy. The optimal values of convergence control parameters and corresponding individual and total residual errors for SWCNTs and MWCNTs are computed by means of homotopy analysis method (HAM based BVPh 2.0. Characteristics of different involved parameters on the velocity, temperature, skin friction coefficient and Nusselt number are discussed. Higher velocity profile is observed for wall thickness parameter in case of water carbon nanotubes when compared with the kerosene oil carbon nanotubes.

Diagnosing the Stagnation Conditions of MagLIF Implosions Using Co and Kr dopants

Science.gov (United States)

Harding, E. C.; Hansen, S. B.; Harvey-Thompson, A. J.; Weis, M. R.; Hahn, K. D.; Gomez, M. R.; Knapp, P. F.; Slutz, S. A.; Geissel, M.; Ampleford, D. J.; Jennings, C. A.; Peterson, K.; Rochau, G. A.; Doron, R.; Stambulchik, E.; Nedostup, O.; Maron, Y.; Golovkin, I.

2017-10-01

Recent experiments on the Z-machine tested several new diagnostic techniques for investigating the stagnation conditions and the origins of the mix present in a Magnetized Liner Inertial Fusion (MagLIF) target. For the first time we have collected K-shell spectra from a low-concentration, Kr dopant placed in the gaseous D2 fuel. In addition, thin Co coatings were strategically applied to three different internal surfaces of the target in order to assess which surfaces actively contribute to the contamination of the fuel. Both imaging spectroscopy and narrow-band crystal imaging were used to identify the location of He-like Co ions. The Te and ne of the Co is inferred by fitting the He-alpha lines and the near-by Li-like satellites. The experimental measurements and the challenges associated with the analysis will be discussed. Sandia Natl Lab is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE NNSA under contract DE-NA-0003525.

An automatic, stagnation point based algorithm for the delineation of Wellhead Protection Areas

Science.gov (United States)

Tosco, Tiziana; Sethi, Rajandrea; di Molfetta, Antonio

2008-07-01

Time-related capture areas are usually delineated using the backward particle tracking method, releasing circles of equally spaced particles around each well. In this way, an accurate delineation often requires both a very high number of particles and a manual capture zone encirclement. The aim of this work was to propose an Automatic Protection Area (APA) delineation algorithm, which can be coupled with any model of flow and particle tracking. The computational time is here reduced, thanks to the use of a limited number of nonequally spaced particles. The particle starting positions are determined coupling forward particle tracking from the stagnation point, and backward particle tracking from the pumping well. The pathlines are postprocessed for a completely automatic delineation of closed perimeters of time-related capture zones. The APA algorithm was tested for a two-dimensional geometry, in homogeneous and nonhomogeneous aquifers, steady state flow conditions, single and multiple wells. Results show that the APA algorithm is robust and able to automatically and accurately reconstruct protection areas with a very small number of particles, also in complex scenarios.

New Stagnation Arc Jet Model Design for Testing ADEPT 3-D Carbon Cloth

Science.gov (United States)

Beck, R.; Chen, Y.-K.; Wercinski, P.; Agrawal, P.; Chavez-Garcia, J.

2017-01-01

The ADEPT concept has been considered as an entry, descent and landing system to enable Human Mars class missions. Ground rules for the Mars studies required aerocapture, orbit, and then entry. The design utilizes a 3-D woven carbon cloth fabric as both heatshield and primary structure and design guidelines required 6 layers remaining after all entry events. The peak heating predicted for the ADEPT carbon cloth was 35 Wcm2 and resulting temperatures were predicted to be 1400K. Predictions for carbon mass loss were performed using equilibrium thermochemistry, which is only accurate for T2000K. Carbon oxidation is kinetically controlled at T2000K, and mass loss drops off considerably from equilibrium values. Design of the cloth thickness and mass would be significantly reduced if kinetics were considered. This effort was to design a stagnation test article design that could be used in the AHF with varying levels of oxygen where the results could be used to develop an engineering model to describe the recession rate of the carbon as a function of the partial pressure of monotomic oxygen.

Longitudinal associations between marital stress and externalizing behavior: Does parental sense of competence mediate processes?

NARCIS (Netherlands)

Eldik, W.M. van; Prinzie, P.; Dekoviç, M.; Haan, A.D. de

2017-01-01

Ecological theories emphasize associations between children and elements within their family system, such as the marital relationship. Within a developmental perspective, we longitudinally examined (a) dynamic associations between marital stress and children's externalizing behavior, (b) mediation

How accurate is the phenotype? – An analysis of developmental noise in a cotton aphid clone

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Babbitt Gregory A

2008-02-01

Full Text Available Abstract Background The accuracy by which phenotype can be reproduced by genotype potentially is important in determining the stability, environmental sensitivity, and evolvability of morphology and other phenotypic traits. Because two sides of an individual represent independent development of the phenotype under identical genetic and environmental conditions, average body asymmetry (or "fluctuating asymmetry" can estimate the developmental instability of the population. The component of developmental instability not explained by intrapopulational differences in gene or environment (or their interaction can be further defined as internal developmental noise. Surprisingly, developmental noise remains largely unexplored despite its potential influence on our interpretations of developmental stability, canalization, and evolvability. Proponents of fluctuating asymmetry as a bioindicator of environmental or genetic stress, often make the assumption that developmental noise is minimal and, therefore, that phenotype can respond sensitively to the environment. However, biologists still have not measured whether developmental noise actually comprises a significant fraction of the overall environmental response of fluctuating asymmetry observed within a population. Results In a morphometric study designed to partition developmental noise from fluctuating asymmetry in the wing morphology of a monoclonal culture of cotton aphid, Aphis gossipyii, it was discovered that fluctuating asymmetry in the aphid wing was nearly four times higher than in other insect species. Also, developmental noise comprised a surprisingly large fraction (≈ 50% of the overall response of fluctuating asymmetry to a controlled graded temperature environment. Fluctuating asymmetry also correlated negatively with temperature, indicating that environmentally-stimulated changes in developmental instability are mediated mostly by changes in the development time of individuals

Parental Depression and Child Outcomes: The Mediating Effects of Abuse and Neglect

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Mustillo, Sarah A.; Dorsey, Shannon; Conover, Kate; Burns, Barbara J.

2011-01-01

Using longitudinal data on 1,813 children and parents from a nationally representative child-welfare sample, National Survey of Child and Adolescent Well-Being (NSCAW), this study investigated physically abusive and neglectful parenting as mediating the effects of parent depression on child mental health by developmental stage. Findings from…

New drugs and indications in 2011. France is better focused on patients' interests after the Mediator scandal, but stagnation elsewhere.

Science.gov (United States)

2012-04-01

Progress in the pharmaceutical sector accounted for only a tiny proportion of the hundred or so new products and indications analysed by Prescrire in 2011. About 1 in 6 new products had more harms than benefits, while more than half of all new products provided no advantages over existing options. One worrisome trend was the expansion of "umbrella" ranges for self-medication. As in previous years, drug regulatory agencies continued to grant marketing authorisation prematurely or on the basis of inadequate evaluation. This was especially true for paediatric medicines, despite some limited progress. In the wake of the Mediator disaster, the French health authorities in charge of patient protection, including the drug regulatory agency, finally reacted by withdrawing many old drugs with negative harm-benefit balances and made an effort to increase transparency and to provide better information on drug-related harms. European authorities showed no signs of similar improvements in early 2012. Drug companies continue to promote their products aggressively, which is not in patients' best interests. The medicalisation of life continues apace, with more and more direct-to-consumer advertising. The Mediator disaster was a wake-up call for French policy makers. In late 2011, several new regulations serving patients' interests were adopted, including greater transparency and better management of conflicts of interest, but as yet, with no major breakthrough in attitudes and procedures.

Longitudinal associations between marital stress and externalizing behavior : Does Parental Sense of Competence Mediate Processes?

NARCIS (Netherlands)

van Eldik, W. M.; Prinzie, Peter; Dekovic, M.; de Haan, A.D.

2017-01-01

Ecological theories emphasize associations between children and elements within their family system, such as the marital relationship. Within a developmental perspective, we longitudinally examined (a) dynamic associations between marital stress and children’s externalizing behavior, (b) mediation

[Influence of home nurture environment on language development and social emotion in children with developmental language disorder].

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Li, Guo-Kai; Liu, Gui-Hua; Qian, Qin-Fang; Ge, Pin; Xie, Yan-Qin; Yang, Min-Yan; Wang, Zhang-Qiong; Ou, Ping

2017-05-01

To investigate the influence of home nurture environment on language development and social emotion in children with developmental language disorder (DLD). The 1-3 Years Child Home Nurture Environment Scale, Gesell Developmental Scale, and Infant-Toddler Social and Emotional Assessment Scale were used for the evaluation of 125 children with DLD. A total of 130 children with normal language development matched for age and sex were enrolled as control group. Compared with the control group, the DLD group had a significantly higher proportion of children in a bad home nurture environment and significantly lower scores of all domains of home nurture environment (Pnurture environment score was positively correlated with the level of language development (r=0.536, Pnurture environment had direct influence on language development in children with DLD and affected their language development via the mediating effect of social emotion. Home nurture environment influences language development and social emotion in children with DLD, and social emotion has a partial mediating effect between home nurture environment and language development.

Building a developmental toxicity ontology.

Science.gov (United States)

Baker, Nancy; Boobis, Alan; Burgoon, Lyle; Carney, Edward; Currie, Richard; Fritsche, Ellen; Knudsen, Thomas; Laffont, Madeleine; Piersma, Aldert H; Poole, Alan; Schneider, Steffen; Daston, George

2018-04-03

As more information is generated about modes of action for developmental toxicity and more data are generated using high-throughput and high-content technologies, it is becoming necessary to organize that information. This report discussed the need for a systematic representation of knowledge about developmental toxicity (i.e., an ontology) and proposes a method to build one based on knowledge of developmental biology and mode of action/ adverse outcome pathways in developmental toxicity. This report is the result of a consensus working group developing a plan to create an ontology for developmental toxicity that spans multiple levels of biological organization. This report provide a description of some of the challenges in building a developmental toxicity ontology and outlines a proposed methodology to meet those challenges. As the ontology is built on currently available web-based resources, a review of these resources is provided. Case studies on one of the most well-understood morphogens and developmental toxicants, retinoic acid, are presented as examples of how such an ontology might be developed. This report outlines an approach to construct a developmental toxicity ontology. Such an ontology will facilitate computer-based prediction of substances likely to induce human developmental toxicity. © 2018 Wiley Periodicals, Inc.

Midlife Eriksonian Psychosocial Development: Setting the Stage for Late-Life Cognitive and Emotional Health

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Malone, Johanna C.; Liu, Sabrina R.; Vaillant, George E.; Rentz, Dorene M.; Waldinger, Robert J.

2016-01-01

Erikson's (1950) model of adult psychosocial development outlines the significance of successful involvement within one's relationships, work, and community for healthy aging. He theorized that the consequences of not meeting developmental challenges included stagnation and emotional despair. Drawing on this model, the present study uses…

Transgenerational developmental programming.

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Aiken, Catherine E; Ozanne, Susan E

2014-01-01

The concept of developmental programming suggests that the early life environment influences offspring characteristics in later life, including the propensity to develop diseases such as the metabolic syndrome. There is now growing evidence that the effects of developmental programming may also manifest in further generations without further suboptimal exposure. This review considers the evidence, primarily from rodent models, for effects persisting to subsequent generations, and evaluates the mechanisms by which developmental programming may be transmitted to further generations. In particular, we focus on the potential role of the intrauterine environment in contributing to a developmentally programmed phenotype in subsequent generations. The literature was systematically searched at http://pubmed.org and http://scholar.google.com to identify published findings regarding transgenerational (F2 and beyond) developmental programming effects in human populations and animal models. Transmission of programming effects is often viewed as a form of epigenetic inheritance, either via the maternal or paternal line. Evidence exists for both germline and somatic inheritance of epigenetic modifications which may be responsible for phenotypic changes in further generations. However, there is increasing evidence for the role of both extra-genomic components of the zygote and the interaction of the developing conceptus with the intrauterine environment in propagating programming effects. The contribution of a suboptimal reproductive tract environment or maternal adaptations to pregnancy may be critical to inheritance of programming effects via the maternal line. As the effects of age exacerbate the programmed metabolic phenotype, advancing maternal age may increase the likelihood of developmental programming effects being transmitted to further generations. We suggest that developmental programming effects could be propagated through the maternal line de novo in generations

Perceptions of Services and Resources as Mediators of Depression among Parents of Children with Developmental Disabilities.

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Herman, Sandra E.; Marcenko, Maureen O.

1997-01-01

This study examined effects of resource perceptions and respite use in a theoretical model of adaptation with 72 parents of children with developmental disabilities. Amount and quality of respite services indirectly affected parental depression. Both quality and respite use were related to helpfulness of the parent's social network. The strongest…

Developmental Pathways to Depressive Symptoms in Adolescence: A Multi-Wave Prospective Study of Negative Emotionality, Stressors, and Anxiety

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Barrocas, Andrea L.; Hankin, Benjamin L.

2011-01-01

This study examined two potential developmental pathways through which the temperament risk factor of negative emotionality (NE) leads to prospective increases in depressive symptoms through the mediating role of stressors and anxious symptoms in a sample of early to middle adolescents (N = 350, 6th-10th graders). The primary hypothesized model…

Preschool Interactive Peer Play Mediates Problem Behavior and Learning for Low-Income Children

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Bulotsky-Shearer, Rebecca J.; Bell, Elizabeth R.; Romero, Sandy L.; Carter, Tracy M.

2012-01-01

The study employed a developmental, ecological, and resiliency framework to examine whether interactive peer play competencies mediated associations between teacher reported problem behavior and learning outcomes for a representative sample of urban low-income children (N = 507 across 46 Head Start classrooms). Structural equation models provided…

Social Control of Hypothalamus-Mediated Male Aggression.

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Yang, Taehong; Yang, Cindy F; Chizari, M Delara; Maheswaranathan, Niru; Burke, Kenneth J; Borius, Maxim; Inoue, Sayaka; Chiang, Michael C; Bender, Kevin J; Ganguli, Surya; Shah, Nirao M

2017-08-16

How environmental and physiological signals interact to influence neural circuits underlying developmentally programmed social interactions such as male territorial aggression is poorly understood. We have tested the influence of sensory cues, social context, and sex hormones on progesterone receptor (PR)-expressing neurons in the ventromedial hypothalamus (VMH) that are critical for male territorial aggression. We find that these neurons can drive aggressive displays in solitary males independent of pheromonal input, gonadal hormones, opponents, or social context. By contrast, these neurons cannot elicit aggression in socially housed males that intrude in another male's territory unless their pheromone-sensing is disabled. This modulation of aggression cannot be accounted for by linear integration of environmental and physiological signals. Together, our studies suggest that fundamentally non-linear computations enable social context to exert a dominant influence on developmentally hard-wired hypothalamus-mediated male territorial aggression. Copyright © 2017 Elsevier Inc. All rights reserved.

Intraspecific variation in social organization by genetic variation, developmental plasticity, social flexibility or entirely extrinsic factors.

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Schradin, Carsten

2013-05-19

Previously, it was widely believed that each species has a specific social organization, but we know now that many species show intraspecific variation in their social organization. Four different processes can lead to intraspecific variation in social organization: (i) genetic variation between individuals owing to local adaptation (between populations) or evolutionarily stable strategies within populations; (ii) developmental plasticity evolved in long-term (more than one generation) unpredictable and short-term (one generation) predictable environments, which is mediated by organizational physiological effects during early ontogeny; (iii) social flexibility evolved in highly unpredictable environments, which is mediated by activational physiological effects in adults; (iv) entirely extrinsic factors such as the death of a dominant breeder. Variation in social behaviour occurs between individuals in the case of genetic variation and developmental plasticity, but within individuals in the case of social flexibility. It is important to study intraspecific variation in social organization to understand the social systems of species because it reveals the mechanisms by which species can adapt to changing environments, offers a useful tool to study the ultimate and proximate causes of sociality, and is an interesting phenomenon by itself that needs scientific explanation.

Developmental trajectories of brain maturation and behavior: Relevance to major mental illnesses

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Sedona Lockhart

2018-05-01

Full Text Available Adverse events in childhood and adolescence, such as social neglect or drug abuse, are known to lead to behavioral changes in young adulthood. This is particularly true for the subset of people who are intrinsically more vulnerable to stressful conditions. Yet the underlying mechanisms for such developmental trajectory from early life insult to aberrant adult behavior remains elusive. Adolescence is a period of dynamic physiological, psychological, and behavioral changes, encompassing a distinct neurodevelopmental stage called the ‘critical period’. During adolescence, the brain is uniquely susceptible to stress. Stress mediators may lead to disturbances to biological processes that can cause permanent alterations in the adult stage, even as severe as the onset of mental illness when paired with genetic risk and environmental factors. Understanding the molecular factors governing the critical period and how stress can disturb the maturation processes will allow for better treatment and prevention of late adolescent/young adult onset psychiatric disorders. Keywords: Adolescence, Critical period, Developmental trajectory, Brain maturation, Adult behavior

Atrial natriuretic peptide regulates Ca channel in early developmental cardiomyocytes.

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Lin Miao

Full Text Available BACKGROUND: Cardiomyocytes derived from murine embryonic stem (ES cells possess various membrane currents and signaling cascades link to that of embryonic hearts. The role of atrial natriuretic peptide (ANP in regulation of membrane potentials and Ca(2+ currents has not been investigated in developmental cardiomyocytes. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the role of ANP in regulating L-type Ca(2+ channel current (I(CaL in different developmental stages of cardiomyocytes derived from ES cells. ANP decreased the frequency of action potentials (APs in early developmental stage (EDS cardiomyocytes, embryonic bodies (EB as well as whole embryo hearts. ANP exerted an inhibitory effect on basal I(CaL in about 70% EDS cardiomyocytes tested but only in about 30% late developmental stage (LDS cells. However, after stimulation of I(CaL by isoproterenol (ISO in LDS cells, ANP inhibited the response in about 70% cells. The depression of I(CaL induced by ANP was not affected by either Nomega, Nitro-L-Arginine methyl ester (L-NAME, a nitric oxide synthetase (NOS inhibitor, or KT5823, a cGMP-dependent protein kinase (PKG selective inhibitor, in either EDS and LDS cells; whereas depression of I(CaL by ANP was entirely abolished by erythro-9-(2-Hydroxy-3-nonyl adenine (EHNA, a selective inhibitor of type 2 phosphodiesterase(PDE2 in most cells tested. CONCLUSION/SIGNIFICANCES: Taken together, these results indicate that ANP induced depression of action potentials and I(CaL is due to activation of particulate guanylyl cyclase (GC, cGMP production and cGMP-activation of PDE2 mediated depression of adenosine 3', 5'-cyclic monophophate (cAMP-cAMP-dependent protein kinase (PKA in early cardiomyogenesis.

Developmental predictors of inattention-hyperactivity from pregnancy to early childhood.

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Stéphanie Foulon

Full Text Available The objective of the study was to characterize the developmental sequence of pre- and postnatal risk factors for inattention-hyperactivity symptoms in preschoolers.Longitudinal data came from a French population based birth cohort study (EDEN; N = 1311 mother-child pairs followed from the pregnancy onwards. Inattention-hyperactivity symptoms were assessed with the Strengths and Difficulties Questionnaire when participating children were 3 years of age. Potential risk factors were classified in four domains (fetal exposures and child somatic characteristics, child temperament, child neurodevelopmental status, psychosocial environment and four periods (before pregnancy, prenatal/birth, infancy, toddlerhood. Their role as potential moderator or mediator was tested with path analysis to determine the developmental sequence.A low family socioeconomic status before pregnancy was the main environmental risk factor for inattention-hyperactivity symptoms at 3 years, and its effect occurred via two pathways. The first was a risk pathway, where lower SES was associated with higher maternal depression and anxiety during pregnancy; then to higher maternal and child distress and dysregulation in infancy; and in turn to higher levels of inattention-hyperactivity at 3 years. The second was a protective pathway, where higher SES was associated with longer duration of breastfeeding during infancy; then to better child neurodevelopmental status in toddlerhood; and in turn to lower levels of inattention-hyperactivity at 3 years.This study identified psychosocial factors at several developmental periods that represent potential targets for preventing the emergence of inattention-hyperactivity symptoms in early childhood.

Altered morphology of the nucleus accumbens in persistent developmental stuttering.

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Neef, Nicole E; Bütfering, Christoph; Auer, Tibor; Metzger, F Luise; Euler, Harald A; Frahm, Jens; Paulus, Walter; Sommer, Martin

2018-03-01

Neuroimaging studies in persistent developmental stuttering repeatedly report altered basal ganglia functions. Together with thalamus and cerebellum, these structures mediate sensorimotor functions and thus represent a plausible link between stuttering and neuroanatomy. However, stuttering is a complex, multifactorial disorder. Besides sensorimotor functions, emotional and social-motivational factors constitute major aspects of the disorder. Here, we investigated cortical and subcortical gray matter regions to study whether persistent developmental stuttering is also linked to alterations of limbic structures. The study included 33 right-handed participants who stutter and 34 right-handed control participants matched for sex, age, and education. Structural images were acquired using magnetic resonance imaging to estimate volumetric characteristics of the nucleus accumbens, hippocampus, amygdala, pallidum, putamen, caudate nucleus, and thalamus. Volumetric comparisons and vertex-based shape comparisons revealed structural differences. The right nucleus accumbens was larger in participants who stutter compared to controls. Recent theories of basal ganglia functions suggest that the nucleus accumbens is a motivation-to-movement interface. A speaker intends to reach communicative goals, but stuttering can derail these efforts. It is therefore highly plausible to find alterations in the motivation-to-movement interface in stuttering. While behavioral studies of stuttering sought to find links between the limbic and sensorimotor system, we provide the first neuroimaging evidence of alterations in the limbic system. Thus, our findings might initialize a unified neurobiological framework of persistent developmental stuttering that integrates sensorimotor and social-motivational neuroanatomical circuitries. Copyright © 2017 Elsevier Inc. All rights reserved.

2-D simulations of the implosion, collapse and stagnation of laser fusion shells

International Nuclear Information System (INIS)

Atzeni, S.; Guerrieri, A.

1989-01-01

We discuss the method, model and first results of 2-D numerical simulations of the entire history of gas-filled shells irradiated by laser pulses with long wavelength non-uniformities. Although this issue has already been addressed in connection with the design of reactor targets, or with the interpretation of experimental results, a complete, clear, and quantitative picture of the relevant phenomenology is still missing. In general, the history of a target can be divided into three phases, namely, the acceleration and inertial phase of the implosion (I;t≤t 0 ), the shock collapse and reflection (II,t 0 ≤t≤t ' 0 ) and the stagnation (t ' 0 ≤t≤t 1 ). In a previous study, we were able to study quantitatively phase I and to get some qualitative information on phase II. At t≅t 0 , however, negative area zones occurred in the mesh of our purely Lagrangian code, and the simulations became unreliable. We have now upgraded our code, by introducing an automatic mesh-rezoning package, which allows us to follow with reasonable accuracy phase II and III of the target implosion. (author) 9 refs., 6 figs

Heat transfer in boundary layer stagnation-point flow towards a shrinking sheet with non-uniform heat flux

International Nuclear Information System (INIS)

Bhattacharyya Krishnendu

2013-01-01

In this paper, the effect of non-uniform heat flux on heat transfer in boundary layer stagnation-point flow over a shrinking sheet is studied. The variable boundary heat fluxes are considered of two types: direct power-law variation with the distance along the sheet and inverse power-law variation with the distance. The governing partial differential equations (PDEs) are transformed into non linear self-similar ordinary differential equations (ODEs) by similarity transformations, and then those are solved using very efficient shooting method. The direct variation and inverse variation of heat flux along the sheet have completely different effects on the temperature distribution. Moreover, the heat transfer characteristics in the presence of non-uniform heat flux for several values of physical parameters are also found to be interesting

Self-Generated Magnetic Fields in the Stagnation Phase of Indirect-Drive Implosions on the National Ignition Facility

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Walsh, C. A.; Chittenden, J. P.; McGlinchey, K.; Niasse, N. P. L.; Appelbe, B. D.

2017-04-01

Three-dimensional extended-magnetohydrodynamic simulations of the stagnation phase of inertial confinement fusion implosion experiments at the National Ignition Facility are presented, showing self-generated magnetic fields over 104 T . Angular high mode-number perturbations develop large magnetic fields, but are localized to the cold, dense hot-spot surface, which is hard to magnetize. When low-mode perturbations are also present, the magnetic fields are injected into the hot core, reaching significant magnetizations, with peak local thermal conductivity reductions greater than 90%. However, Righi-Leduc heat transport effectively cools the hot spot and lowers the neutron spectra-inferred ion temperatures compared to the unmagnetized case. The Nernst effect qualitatively changes the results by demagnetizing the hot-spot core, while increasing magnetizations at the edge and near regions of large heat loss.

Analytical study of the non orthogonal stagnation point flow of a micro polar fluid

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M. Ali. Abbas

2017-01-01

Full Text Available In this paper we consider the steady two dimensional flow of micro polar fluids on a flat plate. The flow under discussion is the modified Hiemenz flow for a micro polar fluid which occurs in the hjkns + skms boundary layer near an orthogonal stagnation point. The full governing equation reduced to a modified Hiemenz flow. The solution to the boundary value problem is governed by two non dimensional parameters, the material parameter K and the ratio of the micro rotation to skin friction parameter n. The obtained nonlinear coupled ordinary differential equations are solved by using the Homotopy perturbation method. Comparison between numerical and analytical solutions of the problem is shown in tables form for different values of the governing parameters K and n. Effects of the material parameter K on the velocity profile and microrotation profiles for different cases of n are discussed graphically as well as numerically. Velocity profile decreases as the material parameter K increases and the microrotation profile increases as the material parameter K increases for different cases of n.

Genome Transfer Prevents Fragmentation and Restores Developmental Potential of Developmentally Compromised Postovulatory Aged Mouse Oocytes

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Mitsutoshi Yamada

2017-03-01

Full Text Available Changes in oocyte quality can have great impact on the developmental potential of early embryos. Here we test whether nuclear genome transfer from a developmentally incompetent to a developmentally competent oocyte can restore developmental potential. Using in vitro oocyte aging as a model system we performed nuclear transfer in mouse oocytes at metaphase II or at the first interphase, and observed that development to the blastocyst stage and to term was as efficient as in control embryos. The increased developmental potential is explained primarily by correction of abnormal cytokinesis at anaphase of meiosis and mitosis, by a reduction in chromosome segregation errors, and by normalization of the localization of chromosome passenger complex components survivin and cyclin B1. These observations demonstrate that developmental decline is primarily due to abnormal function of cytoplasmic factors involved in cytokinesis, while the genome remains developmentally fully competent.

Developmental Science: Past, Present, and Future

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Lerner, Richard M.

2012-01-01

The goal of developmental science is to describe, explain, and optimize intraindividual changes in adaptive developmental regulations and, as well, interindividual differences in such relations, across life. The history of developmental science is reviewed and its current foci, which are framed by relational developmental systems models that…

To compare the efficacy of two kinds of Zhizhu pills in the treatment of functional dyspepsia of spleen-deficiency and qi-stagnation syndrome:a randomized group sequential comparative trial

Science.gov (United States)

2011-01-01

Background In Traditional Chinese Medicine (TCM) theory, functional dyspepsia (FD) can be divided into different syndromes according to different clinical symptoms and signs, and the most common one is spleen-deficiency and qi-stagnation syndrome that can be treated by Chinese traditional patent medicine ---- two kinds of Zhizhu pills, between which the primary difference in ingredients is that one contains immature orange fruit of Citrus aurantium L.(IFCA) and the other contains that of Citrus sinensis Osbeck (IFCS). The trial's objective was to compare the efficacy of two kinds of Zhizhu pills on symptom changes in patients with FD of spleen-deficiency and qi-stagnation syndrome. Methods A randomized, group sequential, double-blinded, multicenter trial was conducted in patients with FD of spleen-deficiency and qi-stagnation syndrome at 3 hospitals in Beijing between June 2003 and May 2005. Participants were randomly allocated into two groups (IFCA group and IFCS group) in a 1:1 ratio, and respectively took one of the two kinds of Zhizhu pills orally, 6 g each time, 3 times a day, for 4 weeks. Statistical analysis was performed with use of a group sequential method, the triangular test (TT). Results A total of 163 patients were randomized, and 3 patients were excluded from analysis because of early dropouts, leaving 160 patients (IFCA group: n = 82; IFCS group: n = 78) for statistical analysis. Three interim analyses were done after 62, 116, and 160 patients had completed their 4-week treatment, respectively. At the third interim analysis, the sample path crossed the upper boundary and the trial was stopped, the cure-markedly effective rates were 45% for IFCS group and 67% for IFCA group, respectively, the one-sided p-value was 0.0036, the median unbiased estimate of the odds ratio (OR) for the benefit of IFCA relative to IFCS was 2.91 with 95%CI: 1.40 to 6.06. No adverse events were observed in the two groups. Conclusions Zhizhu pills containing IFCA was superior

An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics

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Molenaar, Peter C. M.

2015-01-01

The main theme of this paper concerns the persistent critique of Gilbert Gottlieb on developmental behavior genetics and my reactions to this critique, the latter changing from rejection to complete acceptation. Concise characterizations of developmental behavior genetics, developmental systems theory (to which Gottlieb made essential…

The fossil record of phenotypic integration and modularity: A deep-time perspective on developmental and evolutionary dynamics.

Science.gov (United States)

Goswami, Anjali; Binder, Wendy J; Meachen, Julie; O'Keefe, F Robin

2015-04-21

Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because they provide the only information on deep-time developmental and evolutionary dynamics, including trends in trait relationships and their role in shaping organismal diversity. Here, we demonstrate the important perspective on phenotypic integration provided by the fossil record with a study of Smilodon fatalis (saber-toothed cats) and Canis dirus (dire wolves). We quantified temporal trends in size, variance, phenotypic integration, and direct developmental integration (fluctuating asymmetry) through 27,000 y of Late Pleistocene climate change. Both S. fatalis and C. dirus showed a gradual decrease in magnitude of phenotypic integration and an increase in variance and the correlation between fluctuating asymmetry and overall integration through time, suggesting that developmental integration mediated morphological response to environmental change in the later populations of these species. These results are consistent with experimental studies and represent, to our knowledge, the first deep-time validation of the importance of developmental integration in stabilizing morphological evolution through periods of environmental change.

Qualitative methodology in developmental psychology

DEFF Research Database (Denmark)

Demuth, Carolin; Mey, Günter

2015-01-01

Qualitative methodology presently is gaining increasing recognition in developmental psychology. Although the founders of developmental psychology to a large extent already used qualitative procedures, the field was long dominated by a (post) positivistic quantitative paradigm. The increasing rec...... in qualitative research offers a promising avenue to advance the field in this direction.......Qualitative methodology presently is gaining increasing recognition in developmental psychology. Although the founders of developmental psychology to a large extent already used qualitative procedures, the field was long dominated by a (post) positivistic quantitative paradigm. The increasing...

Culture and the Trajectories of Developmental Pathology: Insights from Control and Information Theories.

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Wallace, Rodrick

2018-06-01

Cognition in living entities-and their social groupings or institutional artifacts-is necessarily as complicated as their embedding environments, which, for humans, includes a particularly rich cultural milieu. The asymptotic limit theorems of information and control theories permit construction of a new class of empirical 'regression-like' statistical models for cognitive developmental processes, their dynamics, and modes of dysfunction. Such models may, as have their simpler analogs, prove useful in the study and re-mediation of cognitive failure at and across the scales and levels of organization that constitute and drive the phenomena of life. These new models particularly focus on the roles of sociocultural environment and stress, in a large sense, as both trigger for the failure of the regulation of bio-cognition and as 'riverbanks' determining the channels of pathology, with implications across life-course developmental trajectories. We examine the effects of an embedding cultural milieu and its socioeconomic implementations using the 'lenses' of metabolic optimization, control system theory, and an extension of symmetry-breaking appropriate to information systems. A central implication is that most, if not all, human developmental disorders are fundamentally culture-bound syndromes. This has deep implications for both individual treatment and public health policy.

Phenanthrene causes ocular developmental toxicity in zebrafish embryos and the possible mechanisms involved

International Nuclear Information System (INIS)

Huang, Lixing; Wang, Chonggang; Zhang, Youyu; Wu, Meifang; Zuo, Zhenghong

2013-01-01

Highlights: • Phe exposure caused obvious morphological changes in the retina. • Phe exposure caused apoptosis and reduction of cell proliferation in the retina. • Phe causes ocular toxicity might be via the AhR/Zeb1/Mitf/Pax6 signaling pathway. • AhR is a repressor of Zeb1. -- Abstract: Recent studies show that polycyclic aromatic hydrocarbons (PAHs) may be a candidate cause of developmental defects of the retina, but the mechanism is still unclear. We evaluated the mechanism(s) underlying PAH-induced retinal development defects due to exposure to environmental concentrations of Phenanthrene (Phe) in zebrafish. We found that exposure to environmental concentrations of Phe caused obvious morphological changes, developmental retardation, apoptosis, and reduction of cell proliferation in the retina. Our results indicated that Phe could cause visual system developmental defects. Phe exposure up-regulated aryl hydrocarbon receptor (AhR) and microphthalmia-associated transcription factor (Mtif) expression, and down-regulated zinc finger E-box binding homeobox 1 (Zeb1) and paired box 6 (Pax6). Moreover, we demonstrated that AhR was a repressor of Zeb1. We propose that Phe's ocular toxicity is mediated by up-regulating AhR, which then down-regulates Zeb1, in turn inducing Mitf expression while inhibiting Pax6 expression

Attentional networks in developmental dyscalculia

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Henik Avishai

2010-01-01

Full Text Available Abstract Background Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Methods Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test - interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. Results The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. Conclusions These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

Attentional networks in developmental dyscalculia.

Science.gov (United States)

Askenazi, Sarit; Henik, Avishai

2010-01-07

Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test-interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

Abscisic acid induction of vacuolar H+-ATPase activity in mesembryanthemum crystallinum is developmentally regulated

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Barkla; Vera-Estrella; Maldonado-Gama; Pantoja

1999-07-01

Abscisic acid (ABA) has been implicated as a key component in water-deficit-induced responses, including those triggered by drought, NaCl, and low- temperature stress. In this study a role for ABA in mediating the NaCl-stress-induced increases in tonoplast H+-translocating ATPase (V-ATPase) and Na+/H+ antiport activity in Mesembryanthemum crystallinum, leading to vacuolar Na+ sequestration, were investigated. NaCl or ABA treatment of adult M. crystallinum plants induced V-ATPase H+ transport activity, and when applied in combination, an additive effect on V-ATPase stimulation was observed. In contrast, treatment of juvenile plants with ABA did not induce V-ATPase activity, whereas NaCl treatment resulted in a similar response to that observed in adult plants. Na+/H+ antiport activity was induced in both juvenile and adult plants by NaCl, but ABA had no effect at either developmental stage. Results indicate that ABA-induced changes in V-ATPase activity are dependent on the plant reaching its adult phase, whereas NaCl-induced increases in V-ATPase and Na+/H+ antiport activity are independent of plant age. This suggests that ABA-induced V-ATPase activity may be linked to the stress-induced, developmentally programmed switch from C3 metabolism to Crassulacean acid metabolism in adult plants, whereas, vacuolar Na+ sequestration, mediated by the V-ATPase and Na+/H+ antiport, is regulated through ABA-independent pathways.

Psychotherapy with people with developmental disabilities

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Barbara Zafošnik

2011-08-01

Full Text Available People with developmental disabilities can experience any psychological abnormalitiy and psychiatric illness as do people without developmental disabilities. Due to different diagnostic criteria, assessment procedures and instruments, we lack definite prevalence rates for people with developmental disabilities, also suffering from mental health problems, eventhough most studies place the rate at 20 to 40%. One of the possible treatment alternatives for augmenting psychological well-being is psychotherapy, but is extremely rarely used for people with severe and profound disabilities, where speech cannot be the main therapeutic medium. So, those that are included in the psychotherapuetic process are predominantly clients with mild developmental disabilities, and they are mostly in cognitive-behavioral therapy. Recently, two models of (psychotherapy for persons with severe and profound developmental disabilities were developed: developmental-dynamic relationship therapy and attachment-based behaviour therapy for children. Conceptually, they both originate form developmental psychoanalytic theories.

Executive Functioning Mediates the Effect of Behavioral Problems on Depression in Mothers of Children with Developmental Disabilities

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Chan, Wai; Smith, Leann E.; Greenberg, Jan S.; Hong, Jinkuk; Mailick, Marsha R.

2017-01-01

The present investigation explored long-term relationships of behavioral symptoms of adolescents and adults with developmental disabilities with the mental health of their mothers. Fragile X premutation carrier mothers of an adolescent or adult child with fragile X syndrome (n = 95), and mothers of a grown child with autism (n = 213) were…

The sex ratio of siblings of individuals with a history of developmental language disorder

DEFF Research Database (Denmark)

Mouridsen, Svend Erik; Hauschild, Karen-Marie

2010-01-01

There is a well documented predominance of males diagnosed with neurodevelopmental disorders. The influence of sex steroids upon brain development has been suggested to mediate sex differences in developmental psychopathology, and has been epitomized in the 'extreme male brain theory......'. The objective of this study was to extend previous studies dealing with the extreme male brain theory and to study the sex ratio (proportion of males) in the siblings of 469 individuals with a developmental language disorder (DLD) who were consecutively assessed in the same clinic during a period of 10 years....... Among their 908 live-born siblings, 503 were males and 405 females. This yields a sex ratio of 0.554, which is significantly higher than the Danish live birth sex ratio of 0.514 over the same period (P = 0.02). Our findings are consistent with the hypothesis that male sex hormones may be implicated...

Mediator kinase module and human tumorigenesis.

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Clark, Alison D; Oldenbroek, Marieke; Boyer, Thomas G

2015-01-01

Mediator is a conserved multi-subunit signal processor through which regulatory informatiosn conveyed by gene-specific transcription factors is transduced to RNA Polymerase II (Pol II). In humans, MED13, MED12, CDK8 and Cyclin C (CycC) comprise a four-subunit "kinase" module that exists in variable association with a 26-subunit Mediator core. Genetic and biochemical studies have established the Mediator kinase module as a major ingress of developmental and oncogenic signaling through Mediator, and much of its function in signal-dependent gene regulation derives from its resident CDK8 kinase activity. For example, CDK8-targeted substrate phosphorylation impacts transcription factor half-life, Pol II activity and chromatin chemistry and functional status. Recent structural and biochemical studies have revealed a precise network of physical and functional subunit interactions required for proper kinase module activity. Accordingly, pathologic change in this activity through altered expression or mutation of constituent kinase module subunits can have profound consequences for altered signaling and tumor formation. Herein, we review the structural organization, biological function and oncogenic potential of the Mediator kinase module. We focus principally on tumor-associated alterations in kinase module subunits for which mechanistic relationships as opposed to strictly correlative associations are established. These considerations point to an emerging picture of the Mediator kinase module as an oncogenic unit, one in which pathogenic activation/deactivation through component change drives tumor formation through perturbation of signal-dependent gene regulation. It follows that therapeutic strategies to combat CDK8-driven tumors will involve targeted modulation of CDK8 activity or pharmacologic manipulation of dysregulated CDK8-dependent signaling pathways.

"Does anger regulation mediate the discrimination-mental health link among Mexican-origin adolescents? A longitudinal mediation analysis using multilevel modeling": Correction to Park et al. (2016).

Science.gov (United States)

2017-02-01

Reports an error in "Does Anger Regulation Mediate the Discrimination-Mental Health Link Among Mexican-Origin Adolescents? A Longitudinal Mediation Analysis Using Multilevel Modeling" by Irene J. K. Park, Lijuan Wang, David R. Williams and Margarita Alegría ( Developmental Psychology , Advanced Online Publication, Nov 28, 2016, np). In the article, there were several typographical errors in the Recruitment and Procedures section. The percentage of mothers who responded to survey items should have been 99.3%. Additionally, the youths surveyed at T2 and T3 should have been n=246 . Accordingly, the percentage of youths surveyed in T2 and T3 should have been 91.4% and the percentage of mothers surveyed at T2 and T3 should have been 90.7%. Finally, the youths missing at T2 should have been n= 23, and therefore the attrition rate for youth participants should have been 8.6. All versions of this article have been corrected. (The following abstract of the original article appeared in record 2016-57671-001.) Although prior research has consistently documented the association between racial/ethnic discrimination and poor mental health outcomes, the mechanisms that underlie this link are still unclear. The present 3-wave longitudinal study tested the mediating role of anger regulation in the discrimination-mental health link among 269 Mexican-origin adolescents ( M age = 14.1 years, SD = 1.6; 57% girls), 12 to 17 years old. Three competing anger regulation variables were tested as potential mediators: outward anger expression, anger suppression, and anger control. Longitudinal mediation analyses were conducted using multilevel modeling that disaggregated within-person effects from between-person effects. Results indicated that outward anger expression was a significant mediator; anger suppression and anger control were not significant mediators. Within a given individual, greater racial/ethnic discrimination was associated with more frequent outward anger expression. In turn

Communication-Based Assessment of Developmental Age for Young Children with Developmental Disabilities

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DeVeney, Shari L.; Hoffman, Lesa; Cress, Cynthia J.

2012-01-01

Purpose: In this study, the authors compared a multiple-domain strategy for assessing developmental age of young children with developmental disabilities who were at risk for long-term reliance on augmentative and alternative communication (AAC) with a communication-based strategy composed of receptive language and communication indices that may…

Maternal Obesity, Inflammation, and Developmental Programming

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Stephanie A. Segovia

2014-01-01

Full Text Available The prevalence of obesity, especially in women of child-bearing age, is a global health concern. In addition to increasing the immediate risk of gestational complications, there is accumulating evidence that maternal obesity also has long-term consequences for the offspring. The concept of developmental programming describes the process in which an environmental stimulus, including altered nutrition, during critical periods of development can program alterations in organogenesis, tissue development, and metabolism, predisposing offspring to obesity and metabolic and cardiovascular disorders in later life. Although the mechanisms underpinning programming of metabolic disorders remain poorly defined, it has become increasingly clear that low-grade inflammation is associated with obesity and its comorbidities. This review will discuss maternal metainflammation as a mediator of programming in insulin sensitive tissues in offspring. Use of nutritional anti-inflammatories in pregnancy including omega 3 fatty acids, resveratrol, curcumin, and taurine may provide beneficial intervention strategies to ameliorate maternal obesity-induced programming.

Synchronous Computer-Mediated Dynamic Assessment: A Case Study of L2 Spanish Past Narration

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Darhower, Mark Anthony

2014-01-01

In this study, dynamic assessment is employed to help understand the developmental processes of two university Spanish learners as they produce a series of past narrations in a synchronous computer mediated environment. The assessments were conducted in six weekly one-hour chat sessions about various scenes of a Spanish language film. The analysis…

Developmental origins of brain disorders: roles for dopamine

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Kelli M Money

2013-12-01

Full Text Available Neurotransmitters and neuromodulators, such as dopamine, participate in a wide range of behavioral and cognitive functions in the adult brain, including movement, cognition, and reward. Dopamine-mediated signaling plays a fundamental neurodevelopmental role in forebrain differentiation and circuit formation. These developmental effects, such as modulation of neuronal migration and dendritic growth, occur before synaptogenesis and demonstrate novel roles for dopaminergic signaling beyond neuromodulation at the synapse. Pharmacologic and genetic disruptions demonstrate that these effects are brain region- and receptor subtype-specific. For example, the striatum and frontal cortex exhibit abnormal neuronal structure and function following prenatal disruption of dopamine receptor signaling. Alterations in these processes are implicated in the pathophysiology of neuropsychiatric disorders, and emerging studies of neurodevelopmental disruptions may shed light on the pathophysiology of abnormal neuronal circuitry in neuropsychiatric disorders.

Priming 3D cultures of human mesenchymal stromal cells toward cartilage formation via developmental pathways.

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Centola, Matteo; Tonnarelli, Beatrice; Schären, Stefan; Glaser, Nicolas; Barbero, Andrea; Martin, Ivan

2013-11-01

The field of regenerative medicine has increasingly recognized the importance to be inspired by developmental processes to identify signaling pathways crucial for 3D organogenesis and tissue regeneration. Here, we aimed at recapitulating the first events occurring during limb development (ie, cell condensation and expansion of an undifferentiated mesenchymal cell population) to prime 3D cultures of human bone marrow-derived mesenchymal stromal/stem cells (hBM-MSC) toward the chondrogenic route. Based on embryonic development studies, we hypothesized that Wnt3a and fibroblast growth factor 2 (FGF2) induce hBM-MSC to proliferate in 3D culture as an undifferentiated pool of progenitors (defined by clonogenic capacity and expression of typical markers), retaining chondrogenic potential upon induction by suitable morphogens. hBM-MSC were responsive to Wnt signaling in 3D pellet culture, as assessed by significant upregulation of main target genes and increase of unphosphorylated β-catenin levels. Wnt3a was able to induce a five-fold increase in the number of proliferating hBM-MSC (6.4% vs. 1.3% in the vehicle condition), although total DNA content of the 3D construct was decreasing over time. Preconditioning with Wnt3a improved transforming growth factor-β1 mediated chondrogenesis (30% more glycosaminoglycans/cell in average). In contrast to developmental and 2D MSC culture models, FGF2 antagonized the Wnt-mediated effects. Interestingly, the CD146⁺ subpopulation was found to be more responsive to Wnt3a. The presented data indicate a possible strategy to prime 3D cultures of hBM-MSC by invoking a "developmental engineering" approach. The study also identifies some opportunities and challenges to cross-fertilize skeletal development models and 3D hBM-MSC culture systems.

Developmental plasticity: Friend or foe?

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Michels, Karin B

2017-01-01

Developmental plasticity - the concept that adaptation to changing and unfavorable environmental conditions are possible but may come at the price of compromised health potentials - has evolutionary grounding as it facilitates survival but dissents with fundamental evolutionary principles in that it may advance the lesser fit. It is an important cornerstone of the Developmental Origins of Health and Disease (DOHaD). Unlike evolutionary adaptation developmental plasticity may be short-lived and restricted to one or few generations and inheritance is uncertain. Potential mechanisms include epigenetic modifications adopted in utero which may not transmit to the next generation; future insights may allow adjustments of the outcomes of developmental plasticity.

Oxidation of iridium coating on rhenium coated graphite at elevated temperature in stagnated air

International Nuclear Information System (INIS)

Huang, Yongle; Bai, Shuxin; Zhang, Hong; Ye, Yicong

2015-01-01

Highlights: • Continuous and dense Ir coatings were prepared on graphite by electrodepostion. • The purification of the as-prepared Ir coating was higher than about 99.98%. • The Ir/Re/C specimen kept integrity without significant failures after oxidation. • The average oxidation rate of the Ir coating was about 0.219 mg/(cm 2 min). • Penetrating holes at gains boundaries resulted in the failure of the Ir coating. - Abstract: Continuous and dense iridium coatings were prepared on the rhenium coated graphite specimens by electrodeposition. The iridium/rhenium coated graphite (Ir/Re/C) specimens were oxidized at elevated temperatures in stagnated air for 3600 s. The purification of the as-prepared Ir coating was higher than about 99.98% with the main impurity elements Si, Al, Fe and Ru. After oxidation, the Ir/Re/C specimens kept integrity without significant failures and the average oxidation rate was about 0.219 mg/(cm 2 min). Pores were found at the grain boundaries and concentrated to penetrating holes with the growth of Ir grains, which resulted in disastrous failures of the Ir coating

Oxidation of iridium coating on rhenium coated graphite at elevated temperature in stagnated air

Energy Technology Data Exchange (ETDEWEB)

Huang, Yongle; Bai, Shuxin, E-mail: NUDT_MSE_501@163.com; Zhang, Hong; Ye, Yicong

2015-02-15

Highlights: • Continuous and dense Ir coatings were prepared on graphite by electrodepostion. • The purification of the as-prepared Ir coating was higher than about 99.98%. • The Ir/Re/C specimen kept integrity without significant failures after oxidation. • The average oxidation rate of the Ir coating was about 0.219 mg/(cm{sup 2} min). • Penetrating holes at gains boundaries resulted in the failure of the Ir coating. - Abstract: Continuous and dense iridium coatings were prepared on the rhenium coated graphite specimens by electrodeposition. The iridium/rhenium coated graphite (Ir/Re/C) specimens were oxidized at elevated temperatures in stagnated air for 3600 s. The purification of the as-prepared Ir coating was higher than about 99.98% with the main impurity elements Si, Al, Fe and Ru. After oxidation, the Ir/Re/C specimens kept integrity without significant failures and the average oxidation rate was about 0.219 mg/(cm{sup 2} min). Pores were found at the grain boundaries and concentrated to penetrating holes with the growth of Ir grains, which resulted in disastrous failures of the Ir coating.

Impedance spectroscopy and structural properties of the perovskite-like Sn(Ba,Sr)O3 stagnate

International Nuclear Information System (INIS)

Cuervo Farfán, J.; Olaya, J.J.; Vera López, E.; Landínez Téllez, D.A.; Roa-Rojas, J.

2012-01-01

An exhaustive study of structural, electrical and transport properties on the perovskite stagnate Sn(Ba,Sr)O 3 was performed. Samples of SnBa 1-x Sr x O 3 with 0≤x≤1.00 were prepared by the solid state reaction method. The crystallographic structure was studied by X-ray diffraction experiments and Rietveld refinement using the GSAS code. Results reveal the material synthesized in a cubic structure (space group Pm3-bar m, no. 221) for 0≤x≤0.50 and in an orthorhombic (space group Pnma, no. 62) for x>0.50. The approximate grain size was found from experiments' Scanning Electron Microscopy. The electric response was studied by the Impedance Spectroscopy technique from 10.0 mHz up to 0,10 MHz. Electric polarization measurements for SnSrO 3 and SnBaO 3 were determined through curves of polarization as a function of applied electric field, which reveal the ferroelectric character of the material. From the saturation polarization the dielectric constants of materials were calculated.

The impact of parenting styles on children developmental outcome: The role of academic self-concept as a mediator.

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Sangawi, Hoshiar; Adams, John; Reissland, Nadja

2016-08-23

Although the importance of parenting styles directly influencing child development is well established, fewer studied have examined whether parenting styles also affect children's behavioural problems indirectly, mediated through children's academic self-concept (ASC). We examined direct and shared effects of parenting styles on behavioural problems of 199 Kurdish primary school children with a mean age of 11 years 7 months (range 11 years 5 months to 12 years 3 months). Questionnaires measured parenting styles (child version of Alabama Parenting Questionnaire), assessed children's ASC (Myself-As-Learner Scale) and identified children's behavioural problems with the Strengths and Difficulties Questionnaire (SDQ). PROCESS analysis was used to perform the mediation analysis. The results revealed that positive and negative parenting composites are indirectly related to children's internalising behaviour problems. In addition, ASC partially mediated the relationship between the negative parenting composite and prosocial behaviour. However, the mediation analysis did not show the expected indirect effect of parenting styles on externalising problems as being mediated via ASC. Hence, we argue that the ASC serves as a significant mediator in the relationship between parenting styles with prosocial behaviour and internalising problems. © 2016 International Union of Psychological Science.

Developmental Vitamin D Availability Impacts Hematopoietic Stem Cell Production

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Mauricio Cortes

2016-10-01

Full Text Available Vitamin D insufficiency is a worldwide epidemic affecting billions of individuals, including pregnant women and children. Despite its high incidence, the impact of active vitamin D3 (1,25(OHD3 on embryonic development beyond osteo-regulation remains largely undefined. Here, we demonstrate that 1,25(OHD3 availability modulates zebrafish hematopoietic stem and progenitor cell (HSPC production. Loss of Cyp27b1-mediated biosynthesis or vitamin D receptor (VDR function by gene knockdown resulted in significantly reduced runx1 expression and Flk1+cMyb+ HSPC numbers. Selective modulation in vivo and in vitro in zebrafish indicated that vitamin D3 acts directly on HSPCs, independent of calcium regulation, to increase proliferation. Notably, ex vivo treatment of human HSPCs with 1,25(OHD3 also enhanced hematopoietic colony numbers, illustrating conservation across species. Finally, gene expression and epistasis analysis indicated that CXCL8 (IL-8 was a functional target of vitamin D3-mediated HSPC regulation. Together, these findings highlight the relevance of developmental 1,25(OHD3 availability for definitive hematopoiesis and suggest potential therapeutic utility in HSPC expansion.

Study on changes of hypothalamus-pituitary-target axis hormones in patients with insomnia of fire-symdrome due to the stagnation

International Nuclear Information System (INIS)

Chen Jianfei; Yan Songqin

2007-01-01

Objective: To study the changes of hypothalamus-pituitary-target axis hormones in patients with insomnia of fire-symdrom due to the stagnation of liver-qi. Methods: Serum thyrotropin-releasing hormone (TRH), thyroid stimulating hormone (TSH), growth hormone (GH), free thyroxine (FT 4 ), cortisol levels were measured with immunoradioassay (IMRA) and radioimmunoassay (RIA) in 30 patients with this type of insomnia and 30 controls. Results: The serum TSH levels were significantly lower and serum TRH, GH, cortisol FT 4 levels were significantly higher in the patients than those in controls (P<0.05 or P<0.01). Conclusion: This insomnia syndrome was closely related to the dysfunction of mpothalamus-pituitary-thyroid and adrenal axis. (authors)

Molecular and Chemical Genetic Approaches to Developmental Origins of Aging and Disease in Zebrafish

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Sasaki, Tomoyuki; Kishi, Shuji

2013-01-01

The incidence of diseases increases rapidly with age, accompanied by progressive deteriorations of physiological functions in organisms. Aging-associated diseases are sporadic but mostly inevitable complications arising from senescence. Senescence is often considered the antithesis of early development, but yet there may be factors and mechanisms in common between these two phenomena over the dynamic process of aging. The association between early development and late-onset disease with advancing age is thought to come from a consequence of developmental plasticity, the phenomenon by which one genotype can give rise to a range of physiologically and/or morphologically adaptive states in response to different environmental or genetic perturbations. On the one hand, we hypothesized that the future aging process can be predictive based on adaptivity during the early developmental period. Modulating the thresholds of adaptive plasticity by chemical genetic approaches, we have been investigating whether any relationship exists between the regulatory mechanisms that function in early development and in senescence using the zebrafish (Danio rerio), a small freshwater fish and a useful model animal for genetic studies. We have successfully conducted experiments to isolate zebrafish mutants expressing apparently altered senescence phenotypes during embryogenesis (“embryonic senescence”), subsequently showing shortened lifespan in adulthoods. We anticipate that previously uncharacterized developmental genes may mediate the aging process and play a pivotal role in senescence. On the other hand, unexpected senescence-related genes might also be involved in the early developmental process and regulation. The ease of manipulation using the zebrafish system allows us to conduct an exhaustive exploration of novel genes and small molecular compounds that can be linked to the senescence phenotype, and thereby facilitates searching for the evolutionary and developmental origins

Numerical study of unsteady MHD oblique stagnation point flow and heat transfer due to an oscillating stream

Science.gov (United States)

Javed, T.; Ghaffari, A.; Ahmad, H.

2016-05-01

The unsteady stagnation point flow impinging obliquely on a flat plate in presence of a uniform applied magnetic field due to an oscillating stream has been studied. The governing partial differential equations are transformed into dimensionless form and the stream function is expressed in terms of Hiemenz and tangential components. The dimensionless partial differential equations are solved numerically by using well-known implicit finite difference scheme named as Keller-box method. The obtained results are compared with those available in the literature. It is observed that the results are in excellent agreement with the previous studies. The effects of pertinent parameters involved in the problem namely magnetic parameter, Prandtl number and impinging angle on flow and heat transfer characteristics are illustrated through graphs. It is observed that the influence of magnetic field strength increases the fluid velocity and by the increase of obliqueness parameter, the skin friction increases.

Life Disparity before, during and after Stagnation of Danish Female Life Expectancy. a Cause of Death Analysis and a Comparison with Their Scandinavian Counterparts

DEFF Research Database (Denmark)

Aburto, José Manuel; Wensink, Maarten Jan; Lindahl-Jacobsen, Rune

that as Norway increasingly came to resemble Sweden in terms of high life expectancy, it also came to resemble Sweden in terms of low lifespan inequality. Next, we aim to make similar decompositions for Sweden and Norway, and aim to disentangle cohort effects from the question: what can Denmark do now...... cancers and non-infectious respiratory diseases, offsetting continuous improvement in cardiovascular mortality. Before and after stagnation, life expectancy increased as disparity decreased, as the cardiovascular revolution unfolded. Comparing Denmark and its Scandinavian counterparts, we find...

Identification, characterization and developmental expression of Halloween genes encoding P450 enzymes mediating ecdysone biosynthesis in the tobacco hornworm, Manduca sexta

DEFF Research Database (Denmark)

Rewitz, Kim; Rybczynski, Robert; Warren, James T.

2006-01-01

this work to the tobacco hornworm Manduca sexta, an established model for endocrinological and developmental studies. cDNA clones were obtained for three Manduca orthologs of CYP306A1 (phantom; phm, the 25-hydroxylase), CYP302A1 (disembodied; dib, the 22-hydroxylase) and CYP315A1 (shadow; sad, the 2...... in the developmentally varying steroidogenic capacities of the prothoracic glands during the fifth instar. The consistent expression of the Halloween genes confirms the importance of the prothoracic glands in pupal-adult development. These studies establish Manduca as an excellent model for examining the regulation...

Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

Energy Technology Data Exchange (ETDEWEB)

Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D. [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States); Chen, Albert; Stapleton, Heather M. [Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC (United States); Volz, David C., E-mail: volz@mailbox.sc.edu [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States)

2015-04-15

Highlights: • Triphenyl phosphate-induced toxicity in zebrafish embryos is enhanced in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate uptake or metabolism within zebrafish embryos is not altered in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate decreases expression of cytochrome P450 26a1 in zebrafish embryos. • Triphenyl phosphate inhibits retinoic acid-induced activation of human retinoic acid receptors. - Abstract: Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5–72 h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite – were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may

DEVELOPMENTAL TAXONOMY OF CONDUCT DISORDER

OpenAIRE

Jelena Kostić; Milkica Nešić; Jasminka Marković; Miodrag Stanković

2015-01-01

Conduct disorder is a heterogeneous disorder in terms of etiology, course and prognosis, and currently, there is no singular model that would describe the development of the disorder. The results of empirical research on males confirm this heterogeneity, as they point out to two possible developmental pathways: childhood-onset and adolescentonset type. This paper presents the basic elements of developmental taxonomic theory which argues that there are two different developmental pathways to c...

The Application of a Generativity Model for Older Adults

Science.gov (United States)

Ehlman, Katie; Ligon, Mary

2012-01-01

Generativity is a concept first introduced by Erik Erikson as a part of his psychosocial theory which outlines eight stages of development in the human life. Generativity versus stagnation is the main developmental concern of middle adulthood; however, generativity is also recognized as an important theme in the lives of older adults. Building on…

Expectations from different perspectives on future work outcome of young adults with intellectual and developmental disabilities.

Science.gov (United States)

Holwerda, Anja; Brouwer, Sandra; de Boer, Michiel R; Groothoff, Johan W; van der Klink, Jac J L

2015-03-01

Expectations strongly influence future employment outcomes and social networks seem to mediate employment success of young adults with intellectual and developmental disabilities. The aim of this study is to examine the expectations of young adults with intellectual and developmental disabilities from special needs education, their parents and their school teachers regarding future work and the extent to which these expectations predict work outcome. Data on 341 young adults with intellectual or developmental disabilities, coming from special needs education, aged 17-20 years, and with an ability to work according to the Social Security Institute were examined. The school teacher's expectation was the only perspective that significantly predicted entering competitive employment, with a complementary effect of the expectation of parents and a small additional effect of the expectation of the young adult. Expectations of school teachers and parents are valuable in predicting work outcome. Therefore, it is important for professionals working with the young adult in the transition from school to work to incorporate the knowledge of school teachers and parents regarding the abilities of the young adult to enter competitive employment as a valuable source of information.

Influence of de qi on the immediate analgesic effect of SP6 acupuncture in patients with primary dysmenorrhoea and cold and dampness stagnation: a multicentre randomised controlled trial.

Science.gov (United States)

Zhao, Min-Yi; Zhang, Peng; Li, Jing; Wang, Lin-Peng; Zhou, Wei; Wang, Yan-Xia; She, Yan-Fen; Ma, Liang-Xiao; Wang, Pei; Hu, Ni-Juan; Lin, Chi; Hu, Shang-Qin; Wu, Gui-Wen; Wang, Ya-Feng; Sun, Jun-Jun; Jiang, Si-Zhu; Zhu, Jiang

2017-10-01

The aim of this multicentre randomised controlled trial was to investigate the contribution of de qi to the immediate analgesic effect of acupuncture in patients with primary dysmenorrhoea and the specific traditional Chinese medicine diagnosis cold and dampness stagnation . Eighty-eight patients with primary dysmenorrhoea and cold and dampness stagnation were randomly assigned to de qi (n=43) or no de qi (n=45) groups and underwent 30 min of SP6 acupuncture. The de qi group received deep needling at SP6 with manipulation using thick needles; the no de qi group received shallow needling with no manipulation using thin needles. In both groups the pain scores and actual de qi sensation were evaluated using a visual analogue scale for pain (VAS-P) and the acupuncture de qi clinical assessment scale (ADCAS), respectively. Both groups showed reductions in VAS-P, with no signficant differences between groups. ADCAS scores showed 43/43 and 25/45 patients in de qi and no de qi groups, respectively, actually experienced de qi sensation. Independent of original group allocation, VAS-P reductions associated with actual de qi (n=68) were greater than those without (28.4±18.19 mm vs 14.6±12.28 mm, p=0.008). This study showed no significant difference in VAS-P scores in patients with primary dysmenorrhoea and cold and dampness stagnation immediately after SP6 acupuncture designed to induce or avoid de qi sensation. Both treatments significantly reduced VAS-P relative to baseline. Irrespective of group allocation, patients experiencing actual de qi sensation demonstrated larger reductions in pain score relative to those without, suggesting greater analgesic effects. Chinese Clinical Trial Registry (ChiCTR-TRC-13003086); Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Violence Exposure Subtypes Differentially Mediate the Relation between Callous-Unemotional Traits and Adolescent Delinquency.

Science.gov (United States)

Oberth, Carla; Zheng, Yao; McMahon, Robert J

2017-11-01

Research with children and adolescents has established a link between callous-unemotional (CU) traits and delinquency, as well as a link between violence exposure (witnessing and direct victimization) and diverse negative and antisocial outcomes. Little attention has been paid to investigating the association among CU traits, violence exposure, and various forms of delinquency. Using a sample of 753 adolescents (male =58%; African American =46%), the current study aimed to elucidate the mediating role of violence exposure (measured in grades 7, 8, 10, 11) on the relationship between CU traits measured in grade 7 and later delinquency (i.e., property, violent, drug, and sexual) assessed in grade 12. Total violence exposure (witnessing and direct victimization) mediated the association between CU traits and all forms of delinquency. When looking at witnessing and direct victimization separately, however, only witnessing violence mediated the relationship between CU traits and all forms of delinquency. These results highlight the importance of violence exposure in the CU-delinquency link, and showed the differential roles of indirect and direct forms of violence exposure on the association. Witnessing and direct victimization may involve different underlying mechanisms influencing developmental outcomes in youth. These findings have important implications for understanding developmental models of violence exposure, CU traits, and delinquency, as well as interventions for youth who have experienced both indirect and direct forms of violence.

The stagnation of the Mexican male life expectancy in the first decade of the 21st century: the impact of homicides and diabetes mellitus.

Science.gov (United States)

Canudas-Romo, Vladimir; García-Guerrero, Víctor Manuel; Echarri-Cánovas, Carlos Javier

2015-01-01

In the first decade of the 21st century, the Mexican life expectancy changed from a long trend of increase to stagnation. These changes concur with an increase in deaths by homicides that the country experienced in that decade, and an obesity epidemic that had developed over the last decades of the 20th century. We quantify the impact of causes of death on life expectancy from 2000 to 2010. Two approaches to analyse causes of death are used: the number of life years lost due to each of the causes of death in a given year, and cause-decomposition techniques for comparisons of life expectancy from 2000 to 2010. The apparent stagnation in life expectancy is the result of an increase in deaths by homicides and diabetes mellitus on the one hand, and the positive improvements observed in other causes of death on the other. The negative impact of homicides is particularly observed for ages 15 and 50, and for that of diabetes mellitus at ages above 45 years. There is little basis for optimism regarding the future scenarios of the health of the Mexican population based on the first decade of the 21st century. Male life expectancy would have increased by 2 years if deaths by homicides and diabetes mellitus had been avoided. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Topographic processing in developmental prosopagnosia

DEFF Research Database (Denmark)

Klargaard, Solja K.; Starrfelt, Randi; Petersen, Anders

2016-01-01

deficit in visual processing or visual short-term memory. Interestingly, a classical dissociation could be demonstrated between impaired face memory and preserved topographic memory in two developmental prosopagnosics. We conclude that impairments in topographic memory tend to co-occur with developmental......Anecdotal evidence suggests a relation between impaired spatial (navigational) processing and developmental prosopagnosia. To address this formally, we tested two aspects of topographic processing – that is, perception and memory of mountain landscapes shown from different viewpoints. Participants...

Translating genetic research into preventive intervention: The baseline target moderated mediator design

Directory of Open Access Journals (Sweden)

George W. Howe

2016-01-01

Full Text Available In this paper we present and discuss a novel research approach, the baseline target moderated mediation (BTMM design, that holds substantial promise for advancing our understanding of how genetic research can inform prevention research. We first discuss how genetically informed research on developmental psychopathology can be used to identify potential intervention targets. We then describe the BTMM design, which employs moderated mediation within a longitudinal study to test whether baseline levels of intervention targets moderate the impact of the intervention on change in that target, and whether change in those targets mediates causal impact of preventive or treatment interventions on distal health outcomes. We next discuss how genetically informed BTMM designs can be applied to both microtrials and full-scale prevention trials. We end with a discussion of some of the advantages and limitations of this approach.

Developmental stages of developmental screening: steps to implementation of a successful program.

Science.gov (United States)

Pinto-Martin, Jennifer A; Dunkle, Margaret; Earls, Marian; Fliedner, Dane; Landes, Cynthia

2005-11-01

Through the use of 2-stage screening strategies, research studies have shown that autism spectrum disorders and other developmental disabilities can now be detected reliably and with greater validity and in children as young as 18 months of age. Screening and diagnostic practices in the medical and educational arena lag far behind clinical research, however, with the average patient age at time of diagnosis being 3 to 6 years.We discuss the challenges of instituting universal developmental screening as part of pediatric care and present 2 models of existing or planned programs of early screening for autism spectrum disorder and developmental disability (1 in a community-based setting and 1 in a pediatric setting), and discuss the pros and cons of the different strategies.

Computer-mediated interdisciplinary teams: theory and reality.

Science.gov (United States)

Vroman, Kerryellen; Kovacich, Joann

2002-05-01

The benefit of experience, tempered with the wisdom of hindsight and 5 years of text-based, asynchronous, computer-mediated, interdisciplinary team communications, provides the energy, insights and data shared in this article. Through the theoretical lens of group dynamics and the epistemology of interdisciplinary teaming, we analyze the interactions of a virtual interdisciplinary team to provide an understanding and appreciation of collaborative interdisciplinary communication in the context of interactive technologies. Whilst interactive technologies may require new patterns of language similar to that of learning a foreign language, what is communicated in the interdisciplinary team process does not change. Most important is the recognition that virtual teams, similar to their face-to-face counterparts, undergo the same challenges of interdisciplinary teaming and group developmental processes of formation: forming, storming, norming, performing, and transforming. After examining these dynamics of communication and collaboration in the context of the virtual team, the article concludes with guidelines facilitating interdisciplinary team computer-mediated communication.

Mental health outcomes of developmental coordination disorder in late adolescence.

Science.gov (United States)

Harrowell, Ian; Hollén, Linda; Lingam, Raghu; Emond, Alan

2017-09-01

To assess the relationship between developmental coordination disorder (DCD) and mental health outcomes in late adolescence. Data were analyzed from the Avon Longitudinal Study of Parents and Children. Moderate-to-severe DCD was defined at 7 to 8 years according to the DSM-IV-TR criteria. Mental health was assessed at 16 to 18 years using self-reported questionnaires: Strengths and Difficulties Questionnaire, Short Moods and Feelings Questionnaire, and the Warwick-Edinburgh Mental Well-being Scale. Logistic and linear regressions assessed the associations between DCD and mental health, using multiple imputation to account for missing data. Adjustments were made for socio-economic status, IQ, and social communication difficulties. Adolescents with DCD (n=168) had an increased risk of mental health difficulties (total Strengths and Difficulties Questionnaire score) than their peers (n=3750) (odds ratio 1.78, 95% confidence interval 1.12-2.83, adjusted for socio-economic status and IQ). This was, in part, mediated through poor social communication skills. Adolescent females with DCD (n=59) were more prone to mental health difficulties than males. Greater mental well-being was associated with better self-esteem (β 0.82, pcommunication skills and self-esteem. © 2017 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.

One- and two-dimensional density and temperature measurements of an argon-neon Z-pinch plasma at stagnation

International Nuclear Information System (INIS)

Wong, K.L.; Springer, P.T.; Hammer, J.H.; Iglesias, C.A.; Osterheld, A.L.; Foord, M.E.; Bruns, H.C.; Emig, J.A.; Deeney, C.

1996-10-01

In order to benchmark and improve current 2D radiation magnetohydrodynamic (MHD) models of Z-pinch plasmas, we have performed experiments which characterize the plasma -conditions at stagnation. In the experiments the SATURN pulsed power facility at Sandia National Laboratory was used to create an imploding -Ar-Ne plasma. An absolutely calibrated, high resolution space- and time- resolving Johann crystal spectrometer was used to infer the electron temperature Te from the slope of the hydrogenlike Ne free-bound continuum, and the ion density ni from the Stark broadening of the Ar heliunlike Rydberg series. 2D electron temperature profiles of the plasma are obtained from a set of imaging crystals also focused on the Ne free-bound continuum. We shot two types of gas nozzles in the experiment, annular and uniform fill which varies the amount of mass in the plasma. 2D local thermodynamic equilibrium (LTE) and non-LTE MM models predict a radiating region denser and cooler than measured

Surface kinetics for catalytic combustion of hydrogen-air mixtures on platinum at atmospheric pressure in stagnation flows

Science.gov (United States)

Ikeda, H.; Sato, J.; Williams, F. A.

1995-03-01

Experimental studies of the combustion of premixed hydrogen-air mixtures impinging on the surface of a heated platinum plate at normal atmospheric pressure were performed and employed to draw inferences concerning surface reaction mechanisms and rate parameters applicable under practical conditions of catalytic combustion. Plate and gas temperatures were measured by thermocouples, and concentration profiles of major stable species in the gas were measured by gas-chromatographic analyses of samples withdrawn by quartz probes. In addition, ignition and extinction phenomena were recorded and interpreted with the aid of a heat balance at the surface and a previous flow-field analysis of the stagnation-point boundary layer. From the experimental and theoretical results, conclusions were drawn concerning the surface chemical-kinetic mechanisms and values of the elementary rate parameters that are consistent with the observations. In particular, the activation energy for the surface oxidation step H + OH → H 2O is found to be appreciably less at these high surface coverages than in the low-coverage limit.

Stagnation point flow on bioconvection nanofluid over a stretching/shrinking surface with velocity and thermal slip effects

Science.gov (United States)

Chan, Sze Qi; Aman, Fazlina; Mansur, Syahira

2017-09-01

Nanofluid containing nanometer sized particles has become an ideal thermal conductivity medium for the flow and heat transfer in many industrial and engineering applications due to their high rate of heat transfer. However, swimming microorganisms are imposed into the nanofluid to overcome the instability of nanoparticles due to a bioconvection phenomenon. This paper investigates the stagnation point flow on bioconvection heat transfer of a nanofluid over a stretching/shrinking surface containing gyrotactic microorganisms. Velocity and thermal slip effects are the two conditions incorporated into the model. Similarity transformation is applied to reduce the governing nonlinear partial differential equations into the nonlinear ordinary differential equations. The transformed equations are then solved numerically. The results are displayed in the form of graphs and tables. The effects of these governing parameters on the skin friction coefficient, local Nusselt number, local Sherwood number and the local density of the motile microorganisms are analysed and discussed in details.

Analysis Of Convective Plane Stagnation Point Chemically Reactive Mhd Flow Past A Vertical Porous Plate With A Convective Boundary Condition In The Presence Of A Uniform Magnetic Field.

OpenAIRE

Adeniyan, A.,

2013-01-01

The numerical investigation of a stagnation point boundary layer flow , mass and heat transfer of a steady two dimensional , incompressible , viscous electrically conducting, chemically reacting laminar fluid over a vertical convectively heated , electrically neutral flat plate exposed to a transverse uniform magnetic field has been carried out to examine the influence of the simultaneous presence of the effects of a convective boundary condition, chemical reaction, heat transfer and suctio...

Regulation of DC development and DC-mediated T-cell immunity via CISH

OpenAIRE

Miah, Mohammad Alam; Bae, Yong-Soo

2013-01-01

Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

Regulation of DC development and DC-mediated T-cell immunity via CISH.

Science.gov (United States)

Miah, Mohammad Alam; Bae, Yong-Soo

2013-03-01

Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

Attention to Language in Day Care Attending Children: A Mediating Factor in the Developmental Effects of Otitis Media.

Science.gov (United States)

Feagans, Lynne V.; And Others

Three ways in which otitis media may affect development of hearing are explored. First, developmental effects may be due to illness in general; second, otitis media may cause fluctuating hearing loss which may lead to deficits in language in many areas; and, third, fluctuating hearing loss may have only a temporary effect on the acquisition of…

Ubiquitin-mediated proteolysis in Xenopus extract.

Science.gov (United States)

McDowell, Gary S; Philpott, Anna

2016-01-01

The small protein modifier, ubiquitin, can be covalently attached to proteins in the process of ubiquitylation, resulting in a variety of functional outcomes. In particular, the most commonly-associated and well-studied fate for proteins modified with ubiquitin is their ultimate destruction: degradation by the 26S proteasome via the ubiquitin-proteasome system, or digestion in lysosomes by proteolytic enzymes. From the earliest days of ubiquitylation research, a reliable and versatile "cell-in-a-test-tube" system has been employed in the form of cytoplasmic extracts from the eggs and embryos of the frog Xenopus laevis. Biochemical studies of ubiquitin and protein degradation using this system have led to significant advances particularly in the study of ubiquitin-mediated proteolysis, while the versatility of Xenopus as a developmental model has allowed investigation of the in vivo consequences of ubiquitylation. Here we describe the use and history of Xenopus extract in the study of ubiquitin-mediated protein degradation, and highlight the versatility of this system that has been exploited to uncover mechanisms and consequences of ubiquitylation and proteolysis.

Impedance spectroscopy and structural properties of the perovskite-like Sn(Ba,Sr)O{sub 3} stagnate

Energy Technology Data Exchange (ETDEWEB)

Cuervo Farfan, J. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia); Ciencias Basicas, Universidad Manuela Beltran, Bogota DC (Colombia); Olaya, J.J. [Departamento de Ingenieria Mecanica y Mecatronica, Universidad Nacional de Colombia, Bogota DC (Colombia); Vera Lopez, E. [Grupo de Superficies, Electroquimica y Corrosion, Universidad Pedagogica y Tecnologica de Colombia, Tunja (Colombia); Landinez Tellez, D.A. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia); Roa-Rojas, J., E-mail: jroar@unal.edu.co [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia)

2012-08-15

An exhaustive study of structural, electrical and transport properties on the perovskite stagnate Sn(Ba,Sr)O{sub 3} was performed. Samples of SnBa{sub 1-x}Sr{sub x}O{sub 3} with 0{<=}x{<=}1.00 were prepared by the solid state reaction method. The crystallographic structure was studied by X-ray diffraction experiments and Rietveld refinement using the GSAS code. Results reveal the material synthesized in a cubic structure (space group Pm3-bar m, no. 221) for 0{<=}x{<=}0.50 and in an orthorhombic (space group Pnma, no. 62) for x>0.50. The approximate grain size was found from experiments' Scanning Electron Microscopy. The electric response was studied by the Impedance Spectroscopy technique from 10.0 mHz up to 0,10 MHz. Electric polarization measurements for SnSrO{sub 3} and SnBaO{sub 3} were determined through curves of polarization as a function of applied electric field, which reveal the ferroelectric character of the material. From the saturation polarization the dielectric constants of materials were calculated.

The effect of cognitive education on the performance of students with neurological developmental disabilities.

Science.gov (United States)

Jepsen, Ruthanne H; VonThaden, Karen

2002-01-01

A cognitive education program was developed to facilitate acquisition of cognitive skills and address the learning deficits of adolescent students with neurological, developmental disabilities, and autism. This study examined the outcomes of incorporating mediated cognitive education into special education classrooms. Cognitive education provided cognitive training utilizing REHABIT materials through mediated teaching. Following a matched pair model, forty-six students were assigned to either a treatment or a control group. All students received weekly instruction in Individual Educational Program (IEP) goals. Curriculum areas included IEP objectives in reading, math, social skills, health, science and social studies. Students in the control group received regular classroom instruction. Students in the treatment group participated in cognitive educated one hour per week replacing thirty minutes of reading and thirty minutes of math. Pre and posttest comparisons on measures of intelligence, achievement and adaptive behavior showed those students in the treatment group attained higher scores across measures.

Reading in developmental prosopagnosia

DEFF Research Database (Denmark)

Starrfelt, Randi; Klargaard, Solja K; Petersen, Anders

2018-01-01

exposure durations (targeting the word superiority effect), and d) text reading. RESULTS: Participants with developmental prosopagnosia performed strikingly similar to controls across the four reading tasks. Formal analysis revealed a significant dissociation between word and face recognition......, that is, impaired reading in developmental prosopagnosia. METHOD: We tested 10 adults with developmental prosopagnosia and 20 matched controls. All participants completed the Cambridge Face Memory Test, the Cambridge Face Perception test and a Face recognition questionnaire used to quantify everyday face...... recognition experience. Reading was measured in four experimental tasks, testing different levels of letter, word, and text reading: (a) single word reading with words of varying length,(b) vocal response times in single letter and short word naming, (c) recognition of single letters and short words at brief...

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

Directory of Open Access Journals (Sweden)

Rachel Zoubrinetzky

Full Text Available We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

Science.gov (United States)

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

Abscisic Acid Induction of Vacuolar H+-ATPase Activity in Mesembryanthemum crystallinum Is Developmentally Regulated1

Science.gov (United States)

Barkla, Bronwyn J.; Vera-Estrella, Rosario; Maldonado-Gama, Minerva; Pantoja, Omar

1999-01-01

Abscisic acid (ABA) has been implicated as a key component in water-deficit-induced responses, including those triggered by drought, NaCl, and low- temperature stress. In this study a role for ABA in mediating the NaCl-stress-induced increases in tonoplast H+-translocating ATPase (V-ATPase) and Na+/H+ antiport activity in Mesembryanthemum crystallinum, leading to vacuolar Na+ sequestration, were investigated. NaCl or ABA treatment of adult M. crystallinum plants induced V-ATPase H+ transport activity, and when applied in combination, an additive effect on V-ATPase stimulation was observed. In contrast, treatment of juvenile plants with ABA did not induce V-ATPase activity, whereas NaCl treatment resulted in a similar response to that observed in adult plants. Na+/H+ antiport activity was induced in both juvenile and adult plants by NaCl, but ABA had no effect at either developmental stage. Results indicate that ABA-induced changes in V-ATPase activity are dependent on the plant reaching its adult phase, whereas NaCl-induced increases in V-ATPase and Na+/H+ antiport activity are independent of plant age. This suggests that ABA-induced V-ATPase activity may be linked to the stress-induced, developmentally programmed switch from C3 metabolism to Crassulacean acid metabolism in adult plants, whereas, vacuolar Na+ sequestration, mediated by the V-ATPase and Na+/H+ antiport, is regulated through ABA-independent pathways. PMID:10398716

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia

Science.gov (United States)

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants’ VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition. PMID:26950210

Insulin-like growth factor-1 protects preimplantation embryos from anti-developmental actions of menadione.

Science.gov (United States)

Moss, James I; Pontes, Eduardo; Hansen, Peter James

2009-11-01

Menadione is a naphthoquinone used as a vitamin K source in animal feed that can generate reactive oxygen species (ROS) and cause apoptosis. Here, we examined whether menadione reduces development of preimplantation bovine embryos in a ROS-dependent process and tested the hypothesis that actions of menadione would be reduced by insulin-like growth factor-1 (IGF-1). Menadione caused a concentration-dependent decrease in the proportion of embryos that became blastocysts. All concentrations tested (1, 2.5, and 5.0 microM) inhibited development. Treatment with 100 ng/ml IGF-1 reduced the magnitude of the anti-developmental effects of the two lowest menadione concentrations. Menadione also caused a concentration-dependent increase in the percent of cells positive for the TUNEL reaction. The response was lower for IGF-1-treated embryos. The effects of menadione were mediated by ROS because (1) the anti-developmental effect of menadione was blocked by the antioxidants dithiothreitol and Trolox and (2) menadione caused an increase in ROS generation. Treatment with IGF-1 did not reduce ROS formation in menadione-treated embryos. In conclusion, concentrations of menadione as low as 1.0 muM can compromise development of bovine preimplantation embryos to the blastocyst stage of development in a ROS-dependent mechanism. Anti-developmental actions of menadione can be blocked by IGF-1 through effects downstream of ROS generation.

Loss of FTO antagonises Wnt signaling and leads to developmental defects associated with ciliopathies.

Directory of Open Access Journals (Sweden)

Daniel P S Osborn

Full Text Available Common intronic variants in the Human fat mass and obesity-associated gene (FTO are found to be associated with an increased risk of obesity. Overexpression of FTO correlates with increased food intake and obesity, whilst loss-of-function results in lethality and severe developmental defects. Despite intense scientific discussions around the role of FTO in energy metabolism, the function of FTO during development remains undefined. Here, we show that loss of Fto leads to developmental defects such as growth retardation, craniofacial dysmorphism and aberrant neural crest cells migration in Zebrafish. We find that the important developmental pathway, Wnt, is compromised in the absence of FTO, both in vivo (zebrafish and in vitro (Fto(-/- MEFs and HEK293T. Canonical Wnt signalling is down regulated by abrogated β-Catenin translocation to the nucleus whilst non-canonical Wnt/Ca(2+ pathway is activated via its key signal mediators CaMKII and PKCδ. Moreover, we demonstrate that loss of Fto results in short, absent or disorganised cilia leading to situs inversus, renal cystogenesis, neural crest cell defects and microcephaly in Zebrafish. Congruently, Fto knockout mice display aberrant tissue specific cilia. These data identify FTO as a protein-regulator of the balanced activation between canonical and non-canonical branches of the Wnt pathway. Furthermore, we present the first evidence that FTO plays a role in development and cilia formation/function.

Translating Genetic Research into Preventive Intervention: The Baseline Target Moderated Mediator Design.

Science.gov (United States)

Howe, George W; Beach, Steven R H; Brody, Gene H; Wyman, Peter A

2015-01-01

In this paper we present and discuss a novel research approach, the baseline target moderated mediation (BTMM) design, that holds substantial promise for advancing our understanding of how genetic research can inform prevention research. We first discuss how genetically informed research on developmental psychopathology can be used to identify potential intervention targets. We then describe the BTMM design, which employs moderated mediation within a longitudinal study to test whether baseline levels of intervention targets moderate the impact of the intervention on change in that target, and whether change in those targets mediates causal impact of preventive or treatment interventions on distal health outcomes. We next discuss how genetically informed BTMM designs can be applied to both microtrials and full-scale prevention trials. We use simulated data to illustrate a BTMM, and end with a discussion of some of the advantages and limitations of this approach.

Integrating light-sheet imaging with virtual reality to recapitulate developmental cardiac mechanics.

Science.gov (United States)

Ding, Yichen; Abiri, Arash; Abiri, Parinaz; Li, Shuoran; Chang, Chih-Chiang; Baek, Kyung In; Hsu, Jeffrey J; Sideris, Elias; Li, Yilei; Lee, Juhyun; Segura, Tatiana; Nguyen, Thao P; Bui, Alexander; Sevag Packard, René R; Fei, Peng; Hsiai, Tzung K

2017-11-16

Currently, there is a limited ability to interactively study developmental cardiac mechanics and physiology. We therefore combined light-sheet fluorescence microscopy (LSFM) with virtual reality (VR) to provide a hybrid platform for 3D architecture and time-dependent cardiac contractile function characterization. By taking advantage of the rapid acquisition, high axial resolution, low phototoxicity, and high fidelity in 3D and 4D (3D spatial + 1D time or spectra), this VR-LSFM hybrid methodology enables interactive visualization and quantification otherwise not available by conventional methods, such as routine optical microscopes. We hereby demonstrate multiscale applicability of VR-LSFM to (a) interrogate skin fibroblasts interacting with a hyaluronic acid-based hydrogel, (b) navigate through the endocardial trabecular network during zebrafish development, and (c) localize gene therapy-mediated potassium channel expression in adult murine hearts. We further combined our batch intensity normalized segmentation algorithm with deformable image registration to interface a VR environment with imaging computation for the analysis of cardiac contraction. Thus, the VR-LSFM hybrid platform demonstrates an efficient and robust framework for creating a user-directed microenvironment in which we uncovered developmental cardiac mechanics and physiology with high spatiotemporal resolution.

Evidence for a developmental role for TLR4 in learning and memory.

Directory of Open Access Journals (Sweden)

Eitan Okun

Full Text Available Toll-like receptors (TLRs play essential roles in innate immunity and increasing evidence indicates that these receptors are expressed in neurons, astrocytes and microglia in the brain where they mediate responses to infection, stress and injury. Very little is known about the roles of TLRs in cognition. To test the hypothesis that TLR4 has a role in hippocampus-dependent spatial learning and memory, we used mice deficient for TLR4 and mice receiving chronic TLR4 antagonist infusion to the lateral ventricles in the brain. We found that developmental TLR4 deficiency enhances spatial reference memory acquisition and memory retention, impairs contextual fear-learning and enhances motor functions, traits that were correlated with CREB up-regulation in the hippocampus. TLR4 antagonist infusion into the cerebral ventricles of adult mice did not affect cognitive behavior, but instead affected anxiety responses. Our findings indicate a developmental role for TLR4 in shaping spatial reference memory, and fear learning and memory. Moreover, we show that central TLR4 inhibition using a TLR4 antagonist has no discernible physiological role in regulating spatial and contextual hippocampus-dependent cognitive behavior.

Maternal effects and the evolution of brain size in birds: overlooked developmental constraints.

Science.gov (United States)

Garamszegi, L Z; Biard, C; Eens, M; Møller, A P; Saino, N; Surai, P

2007-01-01

A central dogma for the evolution of brain size posits that the maintenance of large brains incurs developmental costs, because they need prolonged periods to grow during the early ontogeny. Such constraints are supported by the interspecific relationship between ontological differences and relative brain size in birds and mammals. Given that mothers can strongly influence the development of the offspring via maternal effects that potentially involve substances essential for growing brains, we argue that such effects may represent an important but overlooked component of developmental constraints on brain size. To demonstrate the importance of maternal effect on the evolution of brains, we investigated the interspecific relationship between relative brain size and maternal effects, as reflected by yolk testosterone, carotenoids, and vitamins A and E in a phylogenetic study of birds. Females of species with relatively large brains invested more in eggs in terms of testosterone and vitamin E than females of species with small brains. The effects of carotenoid and vitamin A levels on the evolution of relative brain size were weaker and non-significant. The association between relative brain size and yolk testosterone was curvilinear, suggesting that very high testosterone levels can be suppressive. However, at least in moderate physiological ranges, the positive relationship between components of maternal effects and relative brain size may imply one aspect of developmental costs of large brains. The relationship between vitamin E and relative brain size was weakened when we controlled for developmental mode, and thus the effect of this antioxidant may be indirect. Testosterone-enhanced neurogenesis and vitamin E-mediated defence against oxidative stress may have key functions when the brain of the embryo develops, with evolutionary consequences for relative brain size.

Developmental toxicity of engineered nanomaterials in rodents

Energy Technology Data Exchange (ETDEWEB)

Ema, Makoto, E-mail: ema-makoto@aist.go.jp; Gamo, Masashi; Honda, Kazumasa

2016-05-15

We summarized significant effects reported in the literature on the developmental toxicity of engineered nanomaterials (ENMs) in rodents. The developmental toxicity of ENMs included not only structural abnormalities, but also death, growth retardation, and behavioral and functional abnormalities. Most studies were performed on mice using an injection route of exposure. Teratogenic effects were indicated when multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), and TiO{sub 2}-nanoparticles were administered to mice during early gestation. Reactive oxygen species levels were increased in placentas and malformed fetuses and their placentas after prenatal exposure to MWCNTs and SWCNTs, respectively. The pre- and postnatal mortalities and growth retardation in offspring increased after prenatal exposure to ENMs. Histopathological and functional abnormalities were also induced in placentas after prenatal exposure to ENMs. Maternal exposure to ENMs induced behavioral alterations, histopathological and biochemical changes in the central nervous system, increased susceptibility to allergy, transplacental genotoxicity, and vascular, immunological, and reproductive effects in offspring. The size- and developmental stage-dependent placental transfer of ENMs was noted after maternal exposure. Silver accumulated in the visceral yolk sac after being injected with Ag-NPs during early gestation. Although currently available data has provided initial information on the potential developmental toxicity of ENMs, that on the developmental toxicity of ENMs is still very limited. Further studies using well-characterized ENMs, state-of the-art study protocols, and appropriate routes of exposure are required in order to clarify these developmental effects and provide information suitable for risk assessments of ENMs. - Highlights: • We review the developmental toxicity studies of engineered nanomaterials (ENMs). • Various developmental endpoints have been

Early Intervention in Children with Developmental Disabilities

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Beena Johnson

2016-01-01

Full Text Available Developmental disabilities consist of conditions that delay or impair the physical, cognitive, and/or psychological development of children. If not intervened at the earliest, these disabilities will cause significant negative impact on multiple domains of functioning such as learning, language, self-care and capacity for independent living. Common developmental disabilities include autism spectrum disorders, intellectual disabilities, developmental delay and cerebral palsy. About one fourth of young children in developing countries are at risk for or have developmental delay or disabilities. Inadequate stimulation has significant negative impact on physical, socioemotional and cognitive development of children. Hence early scientific intervention programs are necessary in the management of children at risk for developmental delay.

Paternal involvement and early infant neurodevelopment: the mediation role of maternal parenting stress.

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Kim, Minjeong; Kang, Su-Kyoung; Yee, Bangsil; Shim, So-Yeon; Chung, Mira

2016-12-12

Father-child interactions are associated with improved developmental outcomes among infants. However, to the best of our knowledge, no study has addressed the effects of paternal involvement on the neurodevelopment of infants who are less than 6 months of age, and no study has reported how maternal parenting stress mediates the relationship between paternal involvement and infant neurodevelopment during early infancy. This study investigates the direct and indirect relationship between paternal involvement and infant neurodevelopment at 3-4 months of age. The indirect relationship was assessed through the mediating factor of maternal parenting stress. The participants were recruited through the Sesalmaul Research Center's website from April to June 2014. The final data included 255 mothers and their healthy infants, who were aged 3-4 months. The mothers reported paternal involvement and maternal parenting stress by using Korean Parenting Alliance Inventory (K-PAI) and Parenting Stress Index (PSI), respectively. Experts visited the participants' homes to observe infant neurodevelopment, and completed a developmental examination using Korean version of the Ages and Stages Questionnaire II (K-ASQ II). A hierarchical multiple regression analysis was used for data analysis. Infants' mean ages were 106 days and girls accounted for 46.3%. The mean total scores (reference range) of the K-PAI, PSI, and the K-ASQ II were 55.5 (17-68), 45.8 (25-100), and 243.2 (0-300), respectively. Paternal involvement had a positive relationship with K-ASQ II scores (β = 0.29, p parenting stress was negatively related with K-ASQ II scores (β = -0.32, p parenting stress mediated the relationship between paternal involvement and early infant neurodevelopment (Z = 3.24, p parenting stress (β = -0.25, p parenting stress partially mediates that association. This result emphasizes the importance of fathers' involvement and mothers' parenting stress on early infant

Global Processing Speed as a Mediator of Developmental Changes in Children's Auditory Memory Span

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Ferguson, A.N.; Bowey, J.A.

2005-01-01

This study examined the role of global processing speed in mediating age increases in auditory memory span in 5- to 13-year-olds. Children were tested on measures of memory span, processing speed, single-word speech rate, phonological sensitivity, and vocabulary. Structural equation modeling supported a model in which age-associated increases in…

[Contemporary cognitive theories about developmental dyscalculia].

Science.gov (United States)

Castro-Cañizares, D; Estévez-Pérez, N; Reigosa-Crespo, V

To analyze the current theories describing the cognitive mechanisms underlying developmental dyscalculia. The four most researched hypotheses concerning the cognitive deficits related to developmental dyscalculia, as well as experimental evidences supporting or refusing them are presented. The first hypothesis states that developmental dyscalculia is consequence of domain general cognitive deficits. The second hypothesis suggests that it is due to a failure in the development of specialized brain systems dedicated to numerosity processing. The third hypothesis asserts the disorder is caused by a deficit in accessing quantity representation through numerical symbols. The last hypothesis states developmental dyscalculia appears as a consequence of impairments in a generalized magnitude system dedicated to the processing of continuous and discrete magnitudes. None of the hypotheses has been proven more plausible than the rest. Relevant issues rose by them need to be revisited and answered in the light of new experimental designs. In the last years the understanding of cognitive disorders involved in developmental dyscalculia has remarkably increased, but it is nonetheless insufficient. Additional research is required in order to achieve a comprehensive cognitive model of numerical processing development and its disorders. This will improve the diagnostic precision and the effectiveness of developmental dyscalculia intervention strategies.

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

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Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

2015-08-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

[Non-autistic pervasive developmental disorders: Rett syndrome, disintegrative disorder and pervasive developmental disorder not otherwise specified

NARCIS (Netherlands)

Mercadante, M.T.; Gaag, R.J. van der; Schwartzman, J.S.

2006-01-01

The category "Pervasive Developmental Disorders" includes autistic disorder, Asperger's syndrome, Rett's syndrome, childhood disintegrative disorder, and a residual category, named pervasive developmental disorder not otherwise specified. In this review, Rett's syndrome and childhood disintegrative

Life Span Developmental Approach

OpenAIRE

Ali Eryilmaz

2011-01-01

The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of...

Wnt5a signaling is a substantial constituent in bone morphogenetic protein-2-mediated osteoblastogenesis

International Nuclear Information System (INIS)

Nemoto, Eiji; Ebe, Yukari; Kanaya, Sousuke; Tsuchiya, Masahiro; Nakamura, Takashi; Tamura, Masato; Shimauchi, Hidetoshi

2012-01-01

Highlights: ► Wnt5a is identified in osteoblasts in tibial growth plate and bone marrow. ► Osteoblastic differentiation is associated with increased expression of Wnt5a/Ror2. ► Wnt5a/Ror2 signaling is important for BMP-2-mediated osteoblastic differentiation. ► Wnt5a/Ror2 operates independently of BMP-Smad pathway. -- Abstract: Wnts are secreted glycoproteins that mediate developmental and post-developmental physiology by regulating cellular processes including proliferation, differentiation, and apoptosis through β-catenin-dependent canonical and β-catenin-independent noncanonical pathway. It has been reported that Wnt5a activates noncanonical Wnt signaling through receptor tyrosine kinase-like orphan receptor 2 (Ror2). Although it appears that Wnt5a/Ror2 signaling supports normal bone physiology, the biological significance of noncanonical Wnts in osteogenesis is essentially unknown. In this study, we identified expression of Wnt5a in osteoblasts in the ossification zone of the tibial growth plate as well as bone marrow of the rat tibia as assessed by immunohistochemistry. In addition, we show that osteoblastic differentiation mediated by BMP-2 is associated with increased expression of Wnt5a and Ror2 using cultured pre-osteoblasts, MC3T3-E1 cells. Silencing gene expression of Wnt5a and Ror2 in MC3T3-E1 cells results in suppression of BMP-2-mediated osteoblastic differentiation, suggesting that Wnt5a and Ror2 signaling are of substantial importance for BMP-2-mediated osteoblastic differentiation. BMP-2 stimulation induced phosphorylation of Smad1/5/8 in a similar fashion in both siWnt5a-treated cells and control cells, suggesting that Wnt5a was dispensable for the phosphorylation of Smads by BMP-2. Taken together, our results suggest that Wnt5a/Ror2 signaling appears to be involved in BMP-2-mediated osteoblast differentiation in a Smad independent pathway.

Mother–Adolescent Conflict as a Mediator Between Adolescent Problem Behaviors and Maternal Psychological Control

OpenAIRE

Steeger, Christine M.; Gondoli, Dawn M.

2012-01-01

This study examined mother–adolescent conflict as a mediator of longitudinal reciprocal relations between adolescent aggression and depressive symptoms and maternal psychological control. Motivated by family systems theory and the transactions that occur between individual and dyadic levels of the family system, we examined the connections among these variables during a developmental period when children and parents experience significant psychosocial changes. Three years of self-report data ...

What Is a Developmental-Behavioral Pediatrician?

Science.gov (United States)

... social worker. Developmental-behavioral pediatricians work closely with parents, families, and schools. Developmental-behavioral pediatricians understand that children’s development and behavior happen first and foremost in the ...

Trisomy 21 and facial developmental instability.

Science.gov (United States)

Starbuck, John M; Cole, Theodore M; Reeves, Roger H; Richtsmeier, Joan T

2013-05-01

The most common live-born human aneuploidy is trisomy 21, which causes Down syndrome (DS). Dosage imbalance of genes on chromosome 21 (Hsa21) affects complex gene-regulatory interactions and alters development to produce a wide range of phenotypes, including characteristic facial dysmorphology. Little is known about how trisomy 21 alters craniofacial morphogenesis to create this characteristic appearance. Proponents of the "amplified developmental instability" hypothesis argue that trisomy 21 causes a generalized genetic imbalance that disrupts evolutionarily conserved developmental pathways by decreasing developmental homeostasis and precision throughout development. Based on this model, we test the hypothesis that DS faces exhibit increased developmental instability relative to euploid individuals. Developmental instability was assessed by a statistical analysis of fluctuating asymmetry. We compared the magnitude and patterns of fluctuating asymmetry among siblings using three-dimensional coordinate locations of 20 anatomic landmarks collected from facial surface reconstructions in four age-matched samples ranging from 4 to 12 years: (1) DS individuals (n = 55); (2) biological siblings of DS individuals (n = 55); 3) and 4) two samples of typically developing individuals (n = 55 for each sample), who are euploid siblings and age-matched to the DS individuals and their euploid siblings (samples 1 and 2). Identification in the DS sample of facial prominences exhibiting increased fluctuating asymmetry during facial morphogenesis provides evidence for increased developmental instability in DS faces. We found the highest developmental instability in facial structures derived from the mandibular prominence and lowest in facial regions derived from the frontal prominence. Copyright © 2013 Wiley Periodicals, Inc.

Glutamatergic synaptic currents of nigral dopaminergic neurons follow a postnatal developmental sequence

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Edouard ePearlstein

2015-05-01

Full Text Available The spontaneous activity pattern of adult dopaminergic (DA neurons of the substantia nigra pars compacta (SNc results from interactions between intrinsic membrane conductances and afferent inputs. In adult SNc DA neurons, low-frequency tonic background activity is generated by intrinsic pacemaker mechanisms, whereas burst generation depends on intact synaptic inputs in particular the glutamatergic ones. Tonic DA release in the striatum during pacemaking is required to maintain motor activity, and burst firing evokes phasic DA release, necessary for cue-dependent learning tasks. However, it is still unknown how the firing properties of SNc DA neurons mature during postnatal development before reaching the adult state. We studied the postnatal developmental profile of spontaneous and evoked AMPA and NMDA receptor-mediated excitatory postsynaptic currents (EPSCs in SNc DA neurons in brain slices from immature (postnatal days P4-10 and young adult (P30-50 tyrosine hydroxylase (TH-GFP mice. We found that somato-dendritic fields of SNc DA neurons are already mature at P4-10. In contrast, spontaneous glutamatergic EPSCs show a developmental sequence. Spontaneous NMDA EPSCs in particular are larger and more frequent in immature SNc DA neurons than in young adult ones and have a bursty pattern. They are mediated by GluN2B and GluN2D subunit-containing NMDA receptors. The latter generate long-lasting, DQP1105-sensitive, spontaneous EPSCs, which are transiently recorded during this early period. Due to high NMDA activity, immature SNc DA neurons generate large and long lasting NMDA receptor-dependent (APV-sensitive bursts in response to the stimulation of the subthalamic nucleus. We conclude that the transient high NMDA activity allows calcium influx into the dendrites of developing SNc DA neurons.

Developmental Kindergarten Program Evaluation Report.

Science.gov (United States)

Blois, George T.; Cushing, Katherine S.

The evaluation of the Developmental Kindergarten (DK) Program at the Harrison School District #2, Colorado Springs, Colorado, involved pre- and post-testing of student academic gains and interviewing of principals and teachers. The program aimed to provide developmentally appropriate activities for students believed to be "at risk" of…

Developmentally Appropriate Peace Education Curricula

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Lewsader, Joellen; Myers-Walls, Judith A.

2017-01-01

Peace education has been offered to children for decades, but those curricula have been only minimally guided by children's developmental stages and needs. In this article, the authors apply their research on children's developmental understanding of peace along with peace education principles and Vygotsky's sociocultural theory to present…

Nonsense-Mediated RNA Decay Influences Human Embryonic Stem Cell Fate

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Chih-Hong Lou

2016-06-01

Full Text Available Nonsense-mediated RNA decay (NMD is a highly conserved pathway that selectively degrades specific subsets of RNA transcripts. Here, we provide evidence that NMD regulates early human developmental cell fate. We found that NMD factors tend to be expressed at higher levels in human pluripotent cells than in differentiated cells, raising the possibility that NMD must be downregulated to permit differentiation. Loss- and gain-of-function experiments in human embryonic stem cells (hESCs demonstrated that, indeed, NMD downregulation is essential for efficient generation of definitive endoderm. RNA-seq analysis identified NMD target transcripts induced when NMD is suppressed in hESCs, including many encoding signaling components. This led us to test the role of TGF-β and BMP signaling, which we found NMD acts through to influence definitive endoderm versus mesoderm fate. Our results suggest that selective RNA decay is critical for specifying the developmental fate of specific human embryonic cell lineages.

Developmental biology, the stem cell of biological disciplines.

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Gilbert, Scott F

2017-12-01

Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines." Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, developmental biology remains vigorous, pluripotent, and relatively undifferentiated. In many disciplines, especially in evolutionary biology and oncology, the developmental perspective is being reasserted as an important research program.

Developmental toxicology: adequacy of current methods.

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Peters, P W

1998-01-01

Toxicology embraces several disciplines such as carcinogenicity, mutagenicity and reproductive toxicity. Reproductive toxicology is concerned with possible effects of substances on the reproductive process, i.e. on sexual organs and their functions, endocrine regulation, fertilization, transport of the fertilized ovum, implantation, and embryonic, fetal and postnatal development, until the end-differentiation of the organs is achieved. Reproductive toxicology is divided into areas related to male and female fertility, and developmental toxicology. Developmental toxicology can be further broken down into prenatal and postnatal toxicology. Today, much new information is available about the origins of developmental disorders resulting from chemical exposure. While these findings seem to promise important new developments in methodology and research, there is a danger of losing sight of the precepts and principles established in the light of existing knowledge. There is also a danger that we may fail to correct shortcomings in our existing procedures and practice. The aim of this presentation is to emphasize the importance of testing substances for their impact in advance of their use and to underline that we must use the best existing tools for carrying out risk assessments. Moreover, it needs to be stressed that there are many substances that are never assessed with respect to reproductive and developmental toxicity. Similarly, our programmes for post-marketing surveillance with respect to developmental toxicology are grossly inadequate. Our ability to identify risks to normal development and reproduction would be much improved, first if a number of straightforward precepts were always followed and second, if we had a clearer understanding of what we mean by risk and acceptable levels of risk in the context of development. Other aims of this paper are: to stress the complexity of the different stages of normal prenatal development; to note the principles that are

The Mediator Complex MED15 Subunit Mediates Activation of Downstream Lipid-Related Genes by the WRINKLED1 Transcription Factor.

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Kim, Mi Jung; Jang, In-Cheol; Chua, Nam-Hai

2016-07-01

The Mediator complex is known to be a master coordinator of transcription by RNA polymerase II, and this complex is recruited by transcription factors (TFs) to target promoters for gene activation or repression. The plant-specific TF WRINKLED1 (WRI1) activates glycolysis-related and fatty acid biosynthetic genes during embryogenesis. However, no Mediator subunit has yet been identified that mediates WRI1 transcriptional activity. Promoter-β-glucuronidase fusion experiments showed that MEDIATOR15 (MED15) is expressed in the same cells in the embryo as WRI1. We found that the Arabidopsis (Arabidopsis thaliana) MED15 subunit of the Mediator complex interacts directly with WRI1 in the nucleus. Overexpression of MED15 or WRI1 increased transcript levels of WRI1 target genes involved in glycolysis and fatty acid biosynthesis; these genes were down-regulated in wild-type or WRI1-overexpressing plants by silencing of MED15 However, overexpression of MED15 in the wri1 mutant also increased transcript levels of WRI1 target genes, suggesting that MED15 also may act with other TFs to activate downstream lipid-related genes. Chromatin immunoprecipitation assays confirmed the association of MED15 with six WRI1 target gene promoters. Additionally, silencing of MED15 resulted in reduced fatty acid content in seedlings and mature seeds, whereas MED15 overexpression increased fatty acid content in both developmental stages. Similar results were found in wri1 mutant and WRI1 overexpression lines. Together, our results indicate that the WRI1/MED15 complex transcriptionally regulates glycolysis-related and fatty acid biosynthetic genes during embryogenesis. © 2016 American Society of Plant Biologists. All Rights Reserved.

Developmentalism: An Obscure but Pervasive Restriction

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J. E. Stone

1996-04-01

Full Text Available Despite continuing criticism of public education, experimentally demonstrated and field tested teaching methods have been ignored, rejected, and abandoned. Instead of a stable consensus regarding best teaching practices, there seems only an unending succession of innovations. A longstanding educational doctrine appears to underlie this anomalous state of affairs. Termed developmentalism, it presumes "natural" ontogenesis to be optimal and it requires experimentally demonstrated teaching practices to overcome a presumption that they interfere with an optimal developmental trajectory. It also discourages teachers and parents from asserting themselves with children. Instead of effective interventions, it seeks the preservation of a postulated natural perfection. Developmentalism's rich history is expressed in a literature extending over 400 years. Its notable exponents include Jean Jacques Rousseau, John Dewey, and Jean Piaget; and its most recent expressions include "developmentally appropriate practice" and "constructivism." In the years during which it gained ascendance, developmentalism served as a basis for rejecting harsh and inhumane teaching methods. Today it impedes efforts to hold schools accountable for student academic achievement.

Developmental Systems Theory and the Person-Oriented Approach. Commentary on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

Science.gov (United States)

Bergman, Lars R.

2015-01-01

Molenaar's (2015) article concerns Developmental Systems Theory (DST) in relation to behavior genetics and he presents implications of DST for empirical research, especially the need for subject-specific studies. In this commentary, the article is discussed from a broader developmental science perspective, particularly regarded through the lens of…

Developmental plasticity: re-conceiving the genotype.

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Sultan, Sonia E

2017-10-06

In recent decades, the phenotype of an organism (i.e. its traits and behaviour) has been studied as the outcome of a developmental 'programme' coded in its genotype. This deterministic view is implicit in the Modern Synthesis approach to adaptive evolution as a sorting process among genetic variants. Studies of developmental pathways have revealed that genotypes are in fact differently expressed depending on environmental conditions. Accordingly, the genotype can be understood as a repertoire of potential developmental outcomes or norm of reaction. Reconceiving the genotype as an environmental response repertoire rather than a fixed developmental programme leads to three critical evolutionary insights. First, plastic responses to specific conditions often comprise functionally appropriate trait adjustments, resulting in an individual-level, developmental mode of adaptive variation. Second, because genotypes are differently expressed depending on the environment, the genetic diversity available to natural selection is itself environmentally contingent. Finally, environmental influences on development can extend across multiple generations via cytoplasmic and epigenetic factors transmitted to progeny individuals, altering their responses to their own, immediate environmental conditions and, in some cases, leading to inherited but non-genetic adaptations. Together, these insights suggest a more nuanced understanding of the genotype and its evolutionary role, as well as a shift in research focus to investigating the complex developmental interactions among genotypes, environments and previous environments.

Testing the utility of fluorescent proteins in Mimulus lewisii by an Agrobacterium-mediated transient assay.

Science.gov (United States)

Ding, Baoqing; Yuan, Yao-Wu

2016-04-01

The Agrobacterium -mediated transient expression assay by leaf infiltration in Mimulus lewisii is robust. Fluorescent proteins EGFP, EYFP and DsRed give bright fluorescence signals in the infiltrated tissue. Mimulus lewisii is an emerging developmental genetic model system. Recently developed genomic and genetic resources and a stable transformation protocol have greatly facilitated the identification and functional characterization of genes controlling the development of ecologically important floral traits using this species. To further expedite gene and protein function analyses in M. lewisii, we adopted and simplified the Agrobacterium-mediated transient gene expression method routinely used in tobacco plants. With the validated transient assay, we examined the performance of fluorescent proteins EGFP, EYFP and DsRed in M. lewisii. All three proteins gave bright fluorescence signals when transiently expressed in agroinfiltrated leaves. Furthermore, we demonstrated the utility of fluorescent proteins in M. lewisii by showing the nuclear localization of Reduced Carotenoid Pigmentation 1 (RCP1), a recently discovered R2R3-MYB transcription factor that regulates carotenoid pigmentation during flower development. Both the transient assay and the fluorescent proteins are valuable additions to the M. lewisii toolbox, making this emerging genetic and developmental model system even more powerful.

Family Life and Developmental Idealism in Yazd, Iran

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Mohammad Jalal Abbasi-Shavazi

2012-03-01

Full Text Available BACKGROUND This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern families, that modern families help to produce modern societies, and that modern family change is to be expected. OBJECTIVE We examine the extent to which developmental idealism has been disseminated in Iran. We also investigate predictors of the dissemination of developmental idealism. METHODS We use survey data collected in 2007 from a sample of women in Yazd, a city in Iran. We examine the distribution of developmental idealism in the sample and the multivariate predictors of developmental idealism. RESULTS We find considerable support for the expectation that many elements of developmental idealism have been widely disseminated. Statistically significant majorities associate development with particular family attributes, believe that development causes change in families, believe that fertility reductions and age-at-marriage increases help foster development, and perceive family trends in Iran headed toward modernity. As predicted, parental education, respondent education, and income affect adherence to developmental idealism. CONCLUSIONS Developmental idealism has been widely disseminated in Yazd, Iran and is related to social and demographic factors in predicted ways. COMMENTS Although our data come from only one city, we expect that developmental idealism has been widely distributed in Iran, with important implications for family and demographic behavior.

29 CFR 1902.33 - Developmental period.

Science.gov (United States)

2010-07-01

... consideration of developmental changes by OSHA. Generally, whenever a State completes a developmental step, it must submit the resulting plan change as a supplement to its plan to OSHA for approval. OSHA's approval...

One- and two-dimensional density and temperature measurements of an argon-neon Z-pinch plasma at stagnation

International Nuclear Information System (INIS)

Wong, K.L.; Springer, P.T.; Hammer, J.H.; Iglesias, C.A.; Osterheld, A.L.; Foord, M.E.; Bruns, H.C.; Emig, J.A.; Deeney, C.

1997-01-01

In order to benchmark and improve current 2D radiation magnetohydrodynamic (MHD) models of Z-pinch plasmas, we have performed experiments which characterize the plasma conditions at stagnation. In the experiments the SATURN pulsed power facility at Sandia National Laboratory was used to create an imploding Ar-Ne plasma. An absolutely calibrated, high resolution space- and time-resolving Johann crystal spectrometer was used to infer the electron temperature T e from the slope of the hydrogenlike Ne free-bound continuum, and the ion density n i from the Stark broadening of the Ar heliumlike Rydberg series. 2D electron temperature profiles of the plasma are obtained from a set of imaging crystals also focused on the Ne free-bound continuum. We shot two types of gas nozzles in the experiment, annular and uniform fill, which varies the amount of mass in the plasma. 2D local thermodynamic equilibrium (LTE) and non-LTE MHD models predict a radiating region denser and cooler than measured. copyright 1997 American Institute of Physics

Developmental principles: fact or fiction.

Science.gov (United States)

Durston, A J

2012-01-01

While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, "whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm". We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level?) adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them.

The Developmental Work

DEFF Research Database (Denmark)

Møller, Niels; Hvid, Helge

2001-01-01

AbstractIn the nineties, the concept of the developmental work (DW) has become a significant point of orientation for the actors on Danish labour market. The DW has moved the focus of the labour market from wages and working time towards work and production. For employees, the DW promises...... developmental possibilities, influence and responsibility, but also greater social responsibility for the firm. For firms, the DW promises increased competitiveness and better products. In this paper we present the concept of the DW as one which encourages the development of work, production and organisation...... of the firm and show that the DW is different from mainstream management concepts, as the DW...

Future Directions in Sleep and Developmental Psychopathology.

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Meltzer, Lisa J

2017-01-01

It is critical for psychologists to gain a better understanding about the intersection between sleep and developmental psychopathology. However, while many strive to answer the question of whether sleep causes developmental psychopathology, or vice versa, ultimately the relationship between sleep and developmental psychopathology is complex and dynamic. This article considers future directions in the field of clinical child and adolescent psychology that go beyond this mechanistic question, highlighting areas important to address for clinicians and researchers who strive to better understand how best to serve children and adolescents with developmental psychopathology. Questions are presented about what is normal in terms of sleep across development, the role of individual variability in terms of sleep needs and vulnerability to sleep loss, and how sleep may serve as a risk or resilience factor for developmental psychopathology, concluding with considerations for interventions.

Author's Response to Commentaries on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

Science.gov (United States)

Molenaar, Peter C. M.

2015-01-01

In this article, Peter Molenaar responds to three commentaries (this issue) on his article, "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics." He addresses aspects of relational developmental systems (RDS) mentioned and questions raised in each of the…

DEVELOPMENTAL TAXONOMY OF CONDUCT DISORDER

Directory of Open Access Journals (Sweden)

Jelena Kostić

2015-12-01

Full Text Available Conduct disorder is a heterogeneous disorder in terms of etiology, course and prognosis, and currently, there is no singular model that would describe the development of the disorder. The results of empirical research on males confirm this heterogeneity, as they point out to two possible developmental pathways: childhood-onset and adolescentonset type. This paper presents the basic elements of developmental taxonomic theory which argues that there are two different developmental pathways to conduct disorder which have different causes and serve as the basis for the current typology of conduct disorders in the classification systems. Such a typology of conduct disorders in the diagnostic classification allows better understanding, prognosis and choice of treatment.

The Mediator Kinase Module Restrains Epidermal Growth Factor Receptor Signaling and Represses Vulval Cell Fate Specification in Caenorhabditis elegans.

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Grants, Jennifer M; Ying, Lisa T L; Yoda, Akinori; You, Charlotte C; Okano, Hideyuki; Sawa, Hitoshi; Taubert, Stefan

2016-02-01

Cell signaling pathways that control proliferation and determine cell fates are tightly regulated to prevent developmental anomalies and cancer. Transcription factors and coregulators are important effectors of signaling pathway output, as they regulate downstream gene programs. In Caenorhabditis elegans, several subunits of the Mediator transcriptional coregulator complex promote or inhibit vulva development, but pertinent mechanisms are poorly defined. Here, we show that Mediator's dissociable cyclin dependent kinase 8 (CDK8) module (CKM), consisting of cdk-8, cic-1/Cyclin C, mdt-12/dpy-22, and mdt-13/let-19, is required to inhibit ectopic vulval cell fates downstream of the epidermal growth factor receptor (EGFR)-Ras-extracellular signal-regulated kinase (ERK) pathway. cdk-8 inhibits ectopic vulva formation by acting downstream of mpk-1/ERK, cell autonomously in vulval cells, and in a kinase-dependent manner. We also provide evidence that the CKM acts as a corepressor for the Ets-family transcription factor LIN-1, as cdk-8 promotes transcriptional repression by LIN-1. In addition, we find that CKM mutation alters Mediator subunit requirements in vulva development: the mdt-23/sur-2 subunit, which is required for vulva development in wild-type worms, is dispensable for ectopic vulva formation in CKM mutants, which instead display hallmarks of unrestrained Mediator tail module activity. We propose a model whereby the CKM controls EGFR-Ras-ERK transcriptional output by corepressing LIN-1 and by fine tuning Mediator specificity, thus balancing transcriptional repression vs. activation in a critical developmental signaling pathway. Collectively, these data offer an explanation for CKM repression of EGFR signaling output and ectopic vulva formation and provide the first evidence of Mediator CKM-tail module subunit crosstalk in animals. Copyright © 2016 by the Genetics Society of America.

Prenatal ethanol exposure-induced adrenal developmental abnormality of male offspring rats and its possible intrauterine programming mechanisms

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Huang, Hegui; He, Zheng; Zhu, Chunyan; Liu, Lian; Kou, Hao; Shen, Lang [Department of Pharmacology, Wuhan University School of Basic Medical Sciences, Wuhan 430071 (China); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, Wuhan University School of Basic Medical Sciences, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Disorder, Wuhan 430071 (China)

2015-10-01

Fetal adrenal developmental status is the major determinant of fetal tissue maturation and offspring growth. We have previously proposed that prenatal ethanol exposure (PEE) suppresses fetal adrenal corticosterone (CORT) synthesis. Here, we focused on PEE-induced adrenal developmental abnormalities of male offspring rats before and after birth, and aimed to explore its intrauterine programming mechanisms. A rat model of intrauterine growth retardation (IUGR) was established by PEE (4 g/kg·d). In PEE fetus, increased serum CORT concentration and decreased insulin-like growth factor 1 (IGF1) concentration, with lower bodyweight and structural abnormalities as well as a decreased Ki67 expression (proliferative marker), were observed in the male fetal adrenal cortex. Adrenal glucocorticoid (GC)-metabolic activation system was enhanced while gene expression of IGF1 signaling pathway with steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD) was decreased. Furthermore, in the male adult offspring of PEE, serum CORT level was decreased but IGF1 was increased with partial catch-up growth, and Ki67 expression demonstrated no obvious change. Adrenal GC-metabolic activation system was inhibited, while IGF1 signaling pathway and 3β-HSD was enhanced with the steroidogenic factor 1 (SF1), and StAR was down-regulated in the adult adrenal. Based on these findings, we propose a “two-programming” mechanism for PEE-induced adrenal developmental toxicity: “the first programming” is a lower functional programming of adrenal steroidogenesis, and “the second programming” is GC-metabolic activation system-related GC-IGF1 axis programming. - Highlights: • Prenatal ethanol exposure induces adrenal developmental abnormality in offspring rats. • Prenatal ethanol exposure induces intrauterine programming of adrenal steroidogenesis. • Intrauterine GC-IGF1 axis programming might mediate adrenal developmental abnormality.

Prenatal ethanol exposure-induced adrenal developmental abnormality of male offspring rats and its possible intrauterine programming mechanisms

International Nuclear Information System (INIS)

Huang, Hegui; He, Zheng; Zhu, Chunyan; Liu, Lian; Kou, Hao; Shen, Lang; Wang, Hui

2015-01-01

Fetal adrenal developmental status is the major determinant of fetal tissue maturation and offspring growth. We have previously proposed that prenatal ethanol exposure (PEE) suppresses fetal adrenal corticosterone (CORT) synthesis. Here, we focused on PEE-induced adrenal developmental abnormalities of male offspring rats before and after birth, and aimed to explore its intrauterine programming mechanisms. A rat model of intrauterine growth retardation (IUGR) was established by PEE (4 g/kg·d). In PEE fetus, increased serum CORT concentration and decreased insulin-like growth factor 1 (IGF1) concentration, with lower bodyweight and structural abnormalities as well as a decreased Ki67 expression (proliferative marker), were observed in the male fetal adrenal cortex. Adrenal glucocorticoid (GC)-metabolic activation system was enhanced while gene expression of IGF1 signaling pathway with steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD) was decreased. Furthermore, in the male adult offspring of PEE, serum CORT level was decreased but IGF1 was increased with partial catch-up growth, and Ki67 expression demonstrated no obvious change. Adrenal GC-metabolic activation system was inhibited, while IGF1 signaling pathway and 3β-HSD was enhanced with the steroidogenic factor 1 (SF1), and StAR was down-regulated in the adult adrenal. Based on these findings, we propose a “two-programming” mechanism for PEE-induced adrenal developmental toxicity: “the first programming” is a lower functional programming of adrenal steroidogenesis, and “the second programming” is GC-metabolic activation system-related GC-IGF1 axis programming. - Highlights: • Prenatal ethanol exposure induces adrenal developmental abnormality in offspring rats. • Prenatal ethanol exposure induces intrauterine programming of adrenal steroidogenesis. • Intrauterine GC-IGF1 axis programming might mediate adrenal developmental abnormality.

Language used in interaction during developmental science instruction

Science.gov (United States)

Avenia-Tapper, Brianna

The coordination of theory and evidence is an important part of scientific practice. Developmental approaches to instruction, which make the relationship between the abstract and the concrete a central focus of students' learning activity, provide educators with a unique opportunity to strengthen students' coordination of theory and evidence. Therefore, developmental approaches may be a useful instructional response to documented science achievement gaps for linguistically diverse students. However, if we are to leverage the potential of developmental instruction to improve the science achievement of linguistically diverse students, we need more information on the intersection of developmental science instruction and linguistically diverse learning contexts. This manuscript style dissertation uses discourse analysis to investigate the language used in interaction during developmental teaching-learning in three linguistically diverse third grade classrooms. The first manuscript asks how language was used to construct ascension from the abstract to the concrete. The second manuscript asks how students' non-English home languages were useful (or not) for meeting the learning goals of the developmental instructional program. The third manuscript asks how students' interlocutors may influence student choice to use an important discourse practice--justification--during the developmental teaching-learning activity. All three manuscripts report findings relevant to the instructional decisions that teachers need to make when implementing developmental instruction in linguistically diverse contexts.

Developmental Immunotoxicity

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Animal models suggest that the immature immune system is more susceptible to xenobiotics than the fully mature system, and sequelae of developmental immunotoxicant exposure may be persistent well into adulthood. Immune maturation may be delayed by xenobiotic exposure and recover...

Developmental Work

DEFF Research Database (Denmark)

Møller, Niels; Hvid, Helge; Kristensen, Tage Søndergaard

2003-01-01

Human Deveoplment and Working Life - Work for Welfare explores whether the development of human resources at company level can improve individuals' quality of life, companies' possibilities of development, and welfare and democracy in society. Chapter two discuss the concept "developmental work...

The Effectiveness of a Cross-Setting Complementary Staff- and Parent-Mediated Early Intensive Behavioral Intervention for Young Children with ASD

Science.gov (United States)

Fava, Leonardo; Strauss, Kristin; Valeri, Giovanni; D'Elia, Lidia; Arima, Serena; Vicari, Stefano

2011-01-01

We compared the effects of Early Intensive Behavioral Intervention (EIBI) and eclectic intervention in children with ASD on autism severity, developmental performance, adaptive behavior, language skills and challenging behaviors. Twelve children received cross-setting staff- and parent-mediated EIBI of centre-based one-to-one and play sessions as…

The Zebrafish Models to Explore Genetic and Epigenetic Impacts on Evolutionary Developmental Origins of Aging

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Kishi, Shuji

2014-01-01

Can we reset, reprogram, rejuvenate or reverse the organismal aging process? Certain genetic manipulations could at least reset and reprogram epigenetic dynamics beyond phenotypic plasticity and elasticity in cells, which can be further manipulated into organisms. However, in a whole complex aging organism, how can we rejuvenate intrinsic resources and infrastructures in an intact/noninvasive manner? The incidence of diseases increases exponentially with age, accompanied by progressive deteriorations of physiological functions in organisms. Aging-associated diseases are sporadic but essentially inevitable complications arising from senescence. Senescence is often considered the antithesis of early development, but yet there may be factors and mechanisms in common between these two phenomena to rejuvenate over the dynamic process of aging. The association between early development and late-onset disease with advancing age is thought to come from a consequence of developmental plasticity, the phenomenon by which one genotype can give rise to a range of physiologically and/or morphologically adaptive states based on diverse epigenotypes, in response to intrinsic or extrinsic environmental cues and genetic perturbations. We hypothesized that the future aging process can be predictive based on adaptivity during the early developmental period. Modulating the thresholds and windows of plasticity and its robustness by molecular genetic and chemical epigenetic approaches, we have successfully conducted experiments to isolate zebrafish mutants expressing apparently altered senescence phenotypes during their embryonic and/or larval stages (“embryonic/larval senescence”). Subsequently, at least some of these mutant animals were found to show shortened lifespan, while some others would be expected to live longer in adulthoods. We anticipate that previously uncharacterized developmental genes may mediate the aging process and play a pivotal role in senescence. On the other

Assessing the Developmental Neurotoxicity of 27 ...

Science.gov (United States)

Assessing the Developmental Neurotoxicity of 27 Organophosphorus Pesticides Using a Zebrafish Behavioral Assay, Waalkes, M., Hunter, D.L., Jarema, K., Mundy, W., and S. Padilla. The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize organophosphorus pesticides for developmental neurotoxicity. As such, we are exploring a behavioral testing paradigm that can assess the effects of sublethal and subteratogenic concentrations of developmental neurotoxicants on zebrafish (Danio rerio). This in vivo assay quantifies the locomotor response to light stimuli under tandem light and dark conditions in a 96-well plate using a video tracking system on 6 day post fertilization zebrafish larvae. Each of twenty-seven organophosphorus pesticides was tested for their developmental neurotoxic potential by exposing zebrafish embryos/larvae to the pesticide at several concentrations (≤ 100 μM nominal concentration) during the first five days of development, followed by 24 hours of depuration and then behavioral testing. Approximately 22% of the chemicals (Acephate, Dichlorvos, Diazoxon, Bensulide,Tribufos, Tebupirimfos) did not produce any behavioral changes after developmental exposure, while many (Malaoxon Fosthiazate, Dimethoate, Dicrotophos, Ethoprop, Malathion, Naled, Diazinon, Methamidophos, Terbufos, Trichlorfon, Phorate, Pirimiphos-methyl, Profenofos, Z-Tetrachlorvinphos, Chlorpyrifos, Coumaphos, Phosmet, Omethoate) produced changes in swi

Synchronization of developmental processes and defense signaling by growth regulating transcription factors.

Directory of Open Access Journals (Sweden)

Jinyi Liu

Full Text Available Growth regulating factors (GRFs are a conserved class of transcription factor in seed plants. GRFs are involved in various aspects of tissue differentiation and organ development. The implication of GRFs in biotic stress response has also been recently reported, suggesting a role of these transcription factors in coordinating the interaction between developmental processes and defense dynamics. However, the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental pathways are elusive. Here, we report large scale identification of putative target candidates of Arabidopsis GRF1 and GRF3 by comparing mRNA profiles of the grf1/grf2/grf3 triple mutant and those of the transgenic plants overexpressing miR396-resistant version of GRF1 or GRF3. We identified 1,098 and 600 genes as putative targets of GRF1 and GRF3, respectively. Functional classification of the potential target candidates revealed that GRF1 and GRF3 contribute to the regulation of various biological processes associated with defense response and disease resistance. GRF1 and GRF3 participate specifically in the regulation of defense-related transcription factors, cell-wall modifications, cytokinin biosynthesis and signaling, and secondary metabolites accumulation. GRF1 and GRF3 seem to fine-tune the crosstalk between miRNA signaling networks by regulating the expression of several miRNA target genes. In addition, our data suggest that GRF1 and GRF3 may function as negative regulators of gene expression through their association with other transcription factors. Collectively, our data provide new insights into how GRF1 and GRF3 might coordinate the interactions between defense signaling and plant growth and developmental pathways.

Evolutionary and developmental modules.

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Lacquaniti, Francesco; Ivanenko, Yuri P; d'Avella, Andrea; Zelik, Karl E; Zago, Myrka

2013-01-01

The identification of biological modules at the systems level often follows top-down decomposition of a task goal, or bottom-up decomposition of multidimensional data arrays into basic elements or patterns representing shared features. These approaches traditionally have been applied to mature, fully developed systems. Here we review some results from two other perspectives on modularity, namely the developmental and evolutionary perspective. There is growing evidence that modular units of development were highly preserved and recombined during evolution. We first consider a few examples of modules well identifiable from morphology. Next we consider the more difficult issue of identifying functional developmental modules. We dwell especially on modular control of locomotion to argue that the building blocks used to construct different locomotor behaviors are similar across several animal species, presumably related to ancestral neural networks of command. A recurrent theme from comparative studies is that the developmental addition of new premotor modules underlies the postnatal acquisition and refinement of several different motor behaviors in vertebrates.

Sexual dysfunction within an adult developmental perspective.

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Fagan, P J; Meyer, J K; Schmidt, C W

1986-01-01

The focus of this paper is on the adult who has adequately mastered the oedipal stage of psychosexual development and who presents with a sexual dysfunction. Drawing on the developmental sequence of Erik Erikson, the authors suggest that failure to address adequately an adult psychosocial crisis may result in sexual dysfunction. There may be both adult developmental deficits and regression to adolescent and adult stages previously negotiated. Both may be symptomatically represented by sexual dysfunction. The authors urge that the sexual and marital problems be evaluated within an adult developmental framework and that the therapy address the psychosocial issues which are appropriate to the developmental stage of the patient.

Locus of Control Fails to Mediate between Stress and Anxiety and Depression in Parents of Children with a Developmental Disorder

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Hamlyn-Wright, Sarah; Draghi-Lorenz, Riccardo; Ellis, Jason

2007-01-01

Stress, anxiety and depression are raised amongst parents of children with a developmental disorder. However, the processes by which stress leads to depression and anxiety are poorly understood. In a cross-sectional survey, levels of parental stress, depression and anxiety were compared between parents of children with an autistic disorder,…

Use of drawings in children with pervasive developmental disorder during hospitalization: a developmental perspective.

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Stefanatou, Athena

2008-12-01

The level and nature of emotional upheaval and relationship to developmental stage was studied in children with pervasive developmental disorder (PDD) hospitalized for head injury. The sample consisted of 25 hospitalized children aged 5-12 years. Children were asked to make the drawing of a ;person in hospital'. The drawings were evaluated by Koppitz's emotional indicators. Punishment and persecution were the main cognitive constructs of children in order to explain hospitalization.

Neurobehavioural effects of developmental toxicity

DEFF Research Database (Denmark)

Grandjean, Philippe; Landrigan, Philip J

2014-01-01

Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments, affect millions of children worldwide, and some diagnoses seem to be increasing in frequency. Industrial chemicals that injure the developing brain are among...... the known causes for this rise in prevalence. In 2006, we did a systematic review and identified five industrial chemicals as developmental neurotoxicants: lead, methylmercury, polychlorinated biphenyls, arsenic, and toluene. Since 2006, epidemiological studies have documented six additional developmental...... chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity. To coordinate these efforts and to accelerate translation of science into prevention, we propose the urgent formation of a new...

Text Comprehension Mediates Morphological Awareness, Syntactic Processing, and Working Memory in Predicting Chinese Written Composition Performance

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Guan, Connie Qun; Ye, Feifei; Wagner, Richard K.; Meng, Wanjin; Leong, Che Kan

2014-01-01

The goal of the present study was to test opposing views about four issues concerning predictors of individual differences in Chinese written composition: (a) Whether morphological awareness, syntactic processing, and working memory represent distinct and measureable constructs in Chinese or are just manifestations of general language ability; (b) whether they are important predictors of Chinese written composition, and if so, the relative magnitudes and independence of their predictive relations; (c) whether observed predictive relations are mediated by text comprehension; and (d) whether these relations vary or are developmentally invariant across three years of writing development. Based on analyses of the performance of students in grades 4 (n = 246), 5 (n = 242) and 6 (n = 261), the results supported morphological awareness, syntactic processing, and working memory as distinct yet correlated abilities that made independent contributions to predicting Chinese written composition, with working memory as the strongest predictor. However, predictive relations were mediated by text comprehension. The final model accounted for approximately 75 percent of the variance in Chinese written composition. The results were largely developmentally invariant across the three grades from which participants were drawn. PMID:25530630

Developmental Principles: Fact or Fiction

Directory of Open Access Journals (Sweden)

A. J. Durston

2012-01-01

Full Text Available While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, “whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm”. We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level? adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them.

Developmental delay

Science.gov (United States)

Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

Arguments from Developmental Order.

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Stöckle-Schobel, Richard

2016-01-01

In this article, I investigate a special type of argument regarding the role of development in theorizing about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind - getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories. Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasizing the importance of the early cognitive processes and arguments emphasizing the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive) development, and I will present some topics that also pertain to a full-fledged 'philosophy of development.'

Effects of variable properties on MHD heat and mass transfer flow near a stagnation point towards a stretching sheet in a porous medium with thermal radiation

Science.gov (United States)

M. Salem, A.; Rania, Fathy

2012-05-01

The effect of variable viscosity and thermal conductivity on steady magnetohydrodynamic (MHD) heat and mass transfer flow of viscous and incompressible fluid near a stagnation point towards a permeable stretching sheet embedded in a porous medium are presented, taking into account thermal radiation and internal heat genberation/absorbtion. The stretching velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation point. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing fundamental equations are first transformed into a system of ordinary differential equations using a scaling group of transformations and are solved numerically by using the fourth-order Rung—Kutta method with the shooting technique. A comparison with previously published work has been carried out and the results are found to be in good agreement. The results are analyzed for the effect of different physical parameters, such as the variable viscosity and thermal conductivity, the ratio of free stream velocity to stretching velocity, the magnetic field, the porosity, the radiation and suction/injection on the flow, and the heat and mass transfer characteristics. The results indicate that the inclusion of variable viscosity and thermal conductivity into the fluids of light and medium molecular weight is able to change the boundary-layer behavior for all values of the velocity ratio parameter λ except for λ = 1. In addition, the imposition of fluid suction increases both the rate of heat and mass transfer, whereas fluid injection shows the opposite effect.

Effects of variable properties on MHD heat and mass transfer flow near a stagnation point towards a stretching sheet in a porous medium with thermal radiation

International Nuclear Information System (INIS)

Salem, A. M.; Fathy, Rania

2012-01-01

The effect of variable viscosity and thermal conductivity on steady magnetohydrodynamic (MHD) heat and mass transfer flow of viscous and incompressible fluid near a stagnation point towards a permeable stretching sheet embedded in a porous medium are presented, taking into account thermal radiation and internal heat genberation/absorbtion. The stretching velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation point. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing fundamental equations are first transformed into a system of ordinary differential equations using a scaling group of transformations and are solved numerically by using the fourth-order Rung—Kutta method with the shooting technique. A comparison with previously published work has been carried out and the results are found to be in good agreement. The results are analyzed for the effect of different physical parameters, such as the variable viscosity and thermal conductivity, the ratio of free stream velocity to stretching velocity, the magnetic field, the porosity, the radiation and suction/injection on the flow, and the heat and mass transfer characteristics. The results indicate that the inclusion of variable viscosity and thermal conductivity into the fluids of light and medium molecular weight is able to change the boundary-layer behavior for all values of the velocity ratio parameter λ except for λ = 1. In addition, the imposition of fluid suction increases both the rate of heat and mass transfer, whereas fluid injection shows the opposite effect. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Friends' Alcohol-Related Social Networking Site Activity Predicts Escalations in Adolescent Drinking: Mediation by Peer Norms.

Science.gov (United States)

Nesi, Jacqueline; Rothenberg, W Andrew; Hussong, Andrea M; Jackson, Kristina M

2017-06-01

Adolescents' increased use of social networking sites (SNS) coincides with a developmental period of heightened risk for alcohol use initiation. However, little is known regarding associations between adolescents' SNS use and drinking initiation nor the mechanisms of this association. This study examined longitudinal associations among adolescents' exposure to friends' alcohol-related SNS postings, alcohol-favorable peer injunctive norms, and initiation of drinking behaviors. Participants were 658 high-school students who reported on posting of alcohol-related SNS content by self and friends, alcohol-related injunctive norms, and other developmental risk factors for alcohol use at two time points, 1 year apart. Participants also reported on initiation of three drinking behaviors: consuming a full drink, becoming drunk, and heavy episodic drinking (three or more drinks per occasion). Probit regression analyses were used to predict initiation of drinking behaviors from exposure to alcohol-related SNS content. Path analyses examined mediation of this association by peer injunctive norms. Exposure to friends' alcohol-related SNS content predicted adolescents' initiation of drinking and heavy episodic drinking 1 year later, controlling for demographic and known developmental risk factors for alcohol use (i.e., parental monitoring and peer orientation). In addition, alcohol-favorable peer injunctive norms statistically mediated the relationship between alcohol-related SNS exposure and each drinking milestone. Results suggest that social media plays a unique role in contributing to peer influence processes surrounding alcohol use and highlight the need for future investigative and preventive efforts to account for adolescents' changing social environments. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Hyperoxia-triggered aversion behavior in Drosophila foraging larvae is mediated by sensory detection of hydrogen peroxide.

Science.gov (United States)

Kim, Myung Jun; Ainsley, Joshua A; Carder, Justin W; Johnson, Wayne A

2013-12-01

Reactive oxygen species (ROS) in excess have been implicated in numerous chronic illnesses, including asthma, diabetes, aging, cardiovascular disease, and neurodegenerative illness. However, at lower concentrations, ROS can also serve essential routine functions as part of cellular signal transduction pathways. As products of atmospheric oxygen, ROS-mediated signals can function to coordinate external environmental conditions with growth and development. A central challenge has been a mechanistic distinction between the toxic effects of oxidative stress and endogenous ROS functions occurring at much lower concentrations. Drosophila larval aerotactic behavioral assays revealed strong developmentally regulated aversion to mild hyperoxia mediated by H2O2-dependent activation of class IV multidendritic (mdIV) sensory neurons expressing the Degenerin/epithelial Na(+) channel subunit, Pickpocket1 (PPK1). Electrophysiological recordings in foraging-stage larvae (78-84 h after egg laying [AEL]) demonstrated PPK1-dependent activation of mdIV neurons by nanomolar levels of H2O2 well below levels normally associated with oxidative stress. Acute sensitivity was reduced > 100-fold during the larval developmental transition to wandering stage (> 96 h AEL), corresponding to a loss of hyperoxia aversion behavior during the same period. Degradation of endogenous H2O2 by transgenic overexpression of catalase in larval epidermis caused a suppression of hyperoxia aversion behavior. Conversely, disruption of endogenous catalase activity using a UAS-CatRNAi transposon resulted in an enhanced hyperoxia-aversive response. These results demonstrate an essential role for low-level endogenous H2O2 as an environment-derived signal coordinating developmental behavioral transitions.

Desiccation stress induces developmental heterochrony in ...

Indian Academy of Sciences (India)

Stressful environments are known to perturb developmental patterns in insects. In the purview of desiccation as astressor, relatively little is known about the developmental consequences linked with desiccation tolerance. In thisstudy, we have particularly focused on the exploration of the temporal profile of postembryonic ...

Replication and robustness in developmental research.

Science.gov (United States)

Duncan, Greg J; Engel, Mimi; Claessens, Amy; Dowsett, Chantelle J

2014-11-01

Replications and robustness checks are key elements of the scientific method and a staple in many disciplines. However, leading journals in developmental psychology rarely include explicit replications of prior research conducted by different investigators, and few require authors to establish in their articles or online appendices that their key results are robust across estimation methods, data sets, and demographic subgroups. This article makes the case for prioritizing both explicit replications and, especially, within-study robustness checks in developmental psychology. It provides evidence on variation in effect sizes in developmental studies and documents strikingly different replication and robustness-checking practices in a sample of journals in developmental psychology and a sister behavioral science-applied economics. Our goal is not to show that any one behavioral science has a monopoly on best practices, but rather to show how journals from a related discipline address vital concerns of replication and generalizability shared by all social and behavioral sciences. We provide recommendations for promoting graduate training in replication and robustness-checking methods and for editorial policies that encourage these practices. Although some of our recommendations may shift the form and substance of developmental research articles, we argue that they would generate considerable scientific benefits for the field. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

The Comet Cometh: Evolving Developmental Systems.

Science.gov (United States)

Jaeger, Johannes; Laubichler, Manfred; Callebaut, Werner

In a recent opinion piece, Denis Duboule has claimed that the increasing shift towards systems biology is driving evolutionary and developmental biology apart, and that a true reunification of these two disciplines within the framework of evolutionary developmental biology (EvoDevo) may easily take another 100 years. He identifies methodological, epistemological, and social differences as causes for this supposed separation. Our article provides a contrasting view. We argue that Duboule's prediction is based on a one-sided understanding of systems biology as a science that is only interested in functional, not evolutionary, aspects of biological processes. Instead, we propose a research program for an evolutionary systems biology, which is based on local exploration of the configuration space in evolving developmental systems. We call this approach-which is based on reverse engineering, simulation, and mathematical analysis-the natural history of configuration space. We discuss a number of illustrative examples that demonstrate the past success of local exploration, as opposed to global mapping, in different biological contexts. We argue that this pragmatic mode of inquiry can be extended and applied to the mathematical analysis of the developmental repertoire and evolutionary potential of evolving developmental mechanisms and that evolutionary systems biology so conceived provides a pragmatic epistemological framework for the EvoDevo synthesis.

Annual research review: Rare genotypes and childhood psychopathology--uncovering diverse developmental mechanisms of ADHD risk.

Science.gov (United States)

Scerif, Gaia; Baker, Kate

2015-03-01

genotype-defined groups. Crucially, as genetic predispositions modify interaction dynamics from the outset, longitudinal research is required to understand the multi-level developmental processes that mediate symptom evolution. © 2014 Association for Child and Adolescent Mental Health.

A developmental etiological model for drug abuse in men.

Science.gov (United States)

Kendler, Kenneth S; Ohlsson, Henrik; Edwards, Alexis C; Sundquist, Jan; Sundquist, Kristina

2017-10-01

We attempt to develop a relatively comprehensive structural model of risk factors for drug abuse (DA) in Swedish men that illustrates developmental and mediational processes. We examined 20 risk factors for DA in 48,369 men undergoing conscription examinations in 1969-70 followed until 2011 when 2.34% (n=1134) of them had DA ascertained in medical, criminal and pharmacy registries. Risk factors were organized into four developmental tiers reflecting i) birth, ii) childhood/early adolescence, iii) late adolescence, and iv) young adulthood. Structural equational model fitting was performed using Mplus. The best fitting model explained 47.8% of the variance in DA. The most prominent predictors, in order, were: early adolescent externalizing behavior, early adult criminal behavior, early adolescent internalizing behavior, early adult unemployment, early adult alcohol use disorder, and late adolescent drug use. Two major inter-connecting pathways emerged reflecting i) genetic/familial risk and ii) family dysfunction and psychosocial adversity. Generated on a first and tested on a second random half of the sample, a model from these variables predicted DA with an ROC area under the curve of 83.6%. Fifty-nine percent of DA cases arose from subjects in the top decile of risk. DA in men is a highly multifactorial syndrome with risk arising from familial-genetic, psychosocial, behavioral and psychological factors acting and interacting over development. Among the multiple predisposing factors for DA, a range of psychosocial adversities, externalizing psychopathology and lack of social constraints in early adulthood are predominant. Copyright © 2017 Elsevier B.V. All rights reserved.

Developmental programming: impact of prenatal testosterone excess on pre- and postnatal gonadotropin regulation in sheep.

Science.gov (United States)

Manikkam, Mohan; Thompson, Robert C; Herkimer, Carol; Welch, Kathleen B; Flak, Jonathan; Karsch, Fred J; Padmanabhan, Vasantha

2008-04-01

The goal of this study was to explore mechanisms that mediate hypersecretion of LH and progressive loss of cyclicity in female sheep exposed during fetal life to excess testosterone. Our working hypothesis was that prenatal testosterone excess, by its androgenic action, amplifies GnRH-induced LH (but not FSH) secretion and, thus, hypersecretion of LH in adulthood, and that this results from altered developmental gene expression of GnRH and estradiol (E2) receptors, gonadotropin subunits, and paracrine factors that differentially regulate LH and FSH synthesis. We observed that, relative to controls, females exposed during fetal life to excess testosterone, as well as the nor-aromatizable androgen dihydrotestosterone, exhibited enhanced LH but not FSH responses to intermittent delivery of GnRH boluses under conditions in which endogenous LH (GnRH) pulses were suppressed. Luteinizing hormone hypersecretion was more evident in adults than in prepubertal females, and it was associated with development of acyclicity. Measurement of pituitary mRNA concentrations revealed that prenatal testosterone excess induced developmental changes in gene expression of pituitary GnRH and E2 receptors and paracrine modulators of LH and FSH synthesis in a manner consistent with subsequent amplification of LH release. Together, this series of studies suggests that prenatal testosterone excess, by its androgenic action, amplifies GnRH-induced LH response, leading to LH hypersecretion and acyclicity in adulthood, and that this programming involves developmental changes in expression of pituitary genes involved in LH and FSH release.

Longitudinal mediators of achievement in mathematics and reading in typical and atypical development.

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Barnes, Marcia A; Raghubar, Kimberly P; English, Lianne; Williams, Jeffrey M; Taylor, Heather; Landry, Susan

2014-03-01

Longitudinal studies of neurodevelopmental disorders that are diagnosed at or before birth and are associated with specific learning difficulties at school-age provide one method for investigating developmental precursors of later-emerging academic disabilities. Spina bifida myelomeningocele (SBM) is a neurodevelopmental disorder associated with particular problems in mathematics, in contrast to well-developed word reading. Children with SBM (n=30) and typically developing children (n=35) were used to determine whether cognitive abilities measured at 36 and 60 months of age mediated the effect of group on mathematical and reading achievement outcomes at 8.5 and 9.5 years of age. A series of multiple mediator models showed that: visual-spatial working memory at 36 months and phonological awareness at 60 months partially mediated the effect of group on math calculations, phonological awareness partially mediated the effect of group on small addition and subtraction problems on a test of math fluency, and visual-spatial working memory mediated the effect of group on a test of math problem solving. Groups did not differ on word reading, and phonological awareness was the only mediator for reading fluency and reading comprehension. The findings are discussed with reference to theories of mathematical development and disability and with respect to both common and differing cognitive correlates of math and reading. Copyright © 2013 Elsevier Inc. All rights reserved.

Prevalence and sociodemographic determinants of developmental ...

African Journals Online (AJOL)

Birth order and household size also had significant association with delay in various domains. There was no significant association between socioeconomic class and developmental delay in any of the domains. Conclusion: The study showed that developmental delay was relatively common among under-five children in ...

Introducing Newspapers in Developmental Reading Classes

Science.gov (United States)

Karstadt, Roberta; Rey, Victoria M.

2009-01-01

Newspapers are an effective educational and motivational tool in developmental reading classes. However, many students are unfamiliar with newspapers and read them infrequently. In order to foster newspaper reading and familiarize the college freshmen enrolled in their developmental reading classes with newspapers, the writers of this article…

Structure and temperature distribution of a stagnation-point Diesel spray premixed flame

International Nuclear Information System (INIS)

Lin, J.-C.; Lin, Ta-Hui

2005-01-01

We experimentally examine the flow and flame characteristics of a stagnation point premixed flame influenced by Diesel sprays. In the experiment, distributions of drop size, drop axial velocity and its fluctuation as well as the gas phase temperature are measured by using the phase-doppler particle analyzer and a thin thermocouple. As might be expected, similar to the gasoline spray flame, the partially prevaporized Diesel spray flame is composed of a weak blue flame zone, indicating the burning of methane fuel, and a strongly luminous zone containing many bright yellow lines showing the passages of burning Diesel drops. It is found that the axial temperature profiles at various radial positions consist of an upstream preheat region, a maximum temperature downstream of the blue flame and a downstream region with a declined temperature curve because of the heat loss to the quartz plate. The SMD of the drops increases from the upstream preheat region to a maximum near the blue flame and then decreases in the downstream burning zone. Along the axial position, the drops are decelerated in front of the flame but accelerated when passing through the blue flame. It is also interesting to note that the radial distributions of SMD and number density of drops in the upstream region are mainly influenced by small drops flowing outward, since the upstream vaporization of Diesel drops is very limited; while those in the downstream region should be influenced by both small drops flowing outward and Diesel drops burning. From the experimental observations, there are impinging and bouncing of Diesel drops downstream of the spray flame near the quartz plate, resulting in a small amount of soot and carbon deposits on the wall. These interesting phenomena will be reported in the near future

Attention-Deficit/Hyperactivity Disorder and Risk of Substance Use Disorder: Developmental Considerations, Potential Pathways, and Opportunities for Research

Science.gov (United States)

Molina, Brooke S.G.; Pelham, William E.

2014-01-01

Many opportunities to explain ADHD-related risk of substance use/disorder (SUD) remain available for study. We detail these opportunities by considering characteristics of children with ADHD and factors affecting their outcomes side-by-side with overlapping variables in the developmental literature on SUD etiology. Although serious conduct problems are a known contributor to ADHD-related risk of SUD, few studies have considered their emergence developmentally and in relation to other candidate mediators and moderators that could also explain risk and be intervention targets. Common ADHD-related impairments, such as school difficulties, are in need of research. Heterogeneous social impairments have the potential for predisposing, and buffering, influences. Research on neurocognitive domains should move beyond standard executive function batteries to measure deficits in the interface between cognitive control, reward, and motivation. Ultimately, maximizing prediction will depend, as it has in the SUD literature, on simultaneous consideration of multiple risk factors. PMID:24437435

Participation in organized sport and self-esteem across adolescence: the mediating role of perceived sport competence.

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Wagnsson, Stefan; Lindwall, Magnus; Gustafsson, Henrik

2014-12-01

The purpose of the study was to test longitudinal (2 years across three occasions) associations between sport participation (SP) and self-esteem (SE) across adolescence (10-18 years), addressing the mediating role of perceived sport competence (PSC) from a developmental perspective. Three waves of data were collected from three age cohorts (10-12, 13-15, and 16-18 years) of school-aged youth (N = 1358). The results demonstrate that SP and SE are related across time and that PSC has an important mediating role in this relationship, both from a skill development and a self-enhancement perspective. In the skill development model, the mediating role of PSC was significantly stronger in the youngest cohort whereas the effect of PSC on subsequent SP in the self-enhancement model was significantly stronger in the 13-15 age group compared with the youngest age group.

Developmental exposure to an environmental PCB mixture delays the propagation of electrical kindling from the amygdala.

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Bandara, Suren B; Sadowski, Renee N; Schantz, Susan L; Gilbert, Mary E

2017-01-01

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6mg/kg/day of the PCB mixture dissolved in corn oil vehicle 4 weeks prior to mating and continued through gestation and up until postnatal day (PND) 21. On PND 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200μA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating attenuated focal (amygdala) excitability. A delay in kindling progression in the amygdala stands in contrast to our previous finding of increased susceptibility to brainstem-mediated audiogenic seizures in PCB-exposed animals in response to a an intense auditory stimulus. These seemingly divergent results are not unexpected given the distinct source, type, and mechanistic underpinnings of these different seizure models. A delay in epileptogenesis following focal amygdala stimulation may reflect a decrease in neuroplasticity following developmental PCB exposure consistent with reductions in use-dependent synaptic plasticity that

Mediator complex cooperatively regulates transcription of retinoic acid target genes with Polycomb Repressive Complex 2 during neuronal differentiation.

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Fukasawa, Rikiya; Iida, Satoshi; Tsutsui, Taiki; Hirose, Yutaka; Ohkuma, Yoshiaki

2015-11-01

The Mediator complex (Mediator) plays key roles in transcription and functions as the nexus for integration of various transcriptional signals. Previously, we screened for Mediator cyclin-dependent kinase (CDK)-interacting factors and identified three proteins related to chromatin regulation. One of them, SUZ12 is required for both stability and activity of Polycomb Repressive Complex 2 (PRC2). PRC2 primarily suppresses gene expression through histone H3 lysine 27 trimethylation, resulting in stem cell maintenance and differentiation; perturbation of this process leads to oncogenesis. Recent work showed that Mediator contributes to the embryonic stem cell state through DNA loop formation, which is strongly associated with chromatin architecture; however, it remains unclear how Mediator regulates gene expression in cooperation with chromatin regulators (i.e. writers, readers and remodelers). We found that Mediator CDKs interact directly with the PRC2 subunit EZH2, as well as SUZ12. Known PRC2 target genes were deregulated by Mediator CDK knockdown during neuronal differentiation, and both Mediator and PRC2 complexes co-occupied the promoters of developmental genes regulated by retinoic acid. Our results provide a mechanistic link between Mediator and PRC2 during neuronal differentiation. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

The influence of the stagnation zone on the fluid dynamics at the nozzle exit of a confined and submerged impinging jet

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Jeffers, Nicholas; Stafford, Jason; Conway, Ciaran; Punch, Jeff; Walsh, Edmond

2016-02-01

Low profile impinging jets provide a means to achieve high heat transfer coefficients while occupying a small quantity of space. Consequently, they are found in many engineering applications such as electronics cooling, annealing of metals, food processing, and others. This paper investigates the influence of the stagnation zone fluid dynamics on the nozzle exit flow condition of a low profile, submerged, and confined impinging water jet. The jet was geometrically constrained to a round, 16-mm diameter, square-edged nozzle at a jet exit to target surface spacing ( H/ D) that varied between 0.25 choice of inlet boundary conditions in numerical models, and it was found that it is necessary to model a jet tube length {{ L}{/}{ D}} > 0.5—where D is the inner diameter of the jet—in order to minimise modelling uncertainty.

Ethiopia: A Democratic Developmental State?

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Fesseha Mulu Gebremariam

2017-12-01

Full Text Available The ruling Ethiopia People’s Revolutionary Democratic Front (EPRDF in its notable second reform appraisal held in the aftermath of the 2005 national election concluded that the utmost priority of the government should be realizing fastest and sustainable economic growth that fairly benefits its citizens’ unless the very existence of the country wouldn’t be guaranteed. Given the history of poverty reduction in developing countries, particularly in Africa, EPRDF realized that it is unthinkable to eradicate poverty from Ethiopia adopting neo-liberalism. Above all, the miraculous economic transformation of the South East Asian countries like South Korea, Taiwan, Singapore and Hong Kong has proved that there is another way to development, not just neo-liberalism. Accordingly, EPRDF, after examining South Korea’s and Taiwan’s history of economic development in particular where both countries have had a large section of rural population unlike Hong Kong and Singapore where both are urban, found ‘developmental state’ relevant to Ethiopia. However, unlike these countries which were originally under non-democratic regimes where their leaders fear the rural peasant and external aggression from their communist rivals, EPRDF has had a great support of rural and urban population with no imminent foreign threat(s, and decided to execute the ideology rather under the umbrella of democracy. Therefore, employing secondary sources, this desk study aims to analyze whether Ethiopia is a ‘democratic developmental state?’ And, concludes that given the practices of the government vis-a-vis the principles of democracy and developmental state, Ethiopia couldn’t be taken as best model for democratic developmental state, rather emerging developmental state.

Pivotal behavior as the mediator of the relationship between parental responsiveness and children's symbolic behavior.

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Chiu, Chun-Hao; Lin, Chu-Sui; Mahoney, Gerald; Cheng, Shu-Fen; Chang, Shu-Hui

2017-08-01

Previous research with parents and children with developmental disabilities indicated that the relationship between mothers' responsive style of interaction and children's rate of development was mediated by the simultaneous relationship between mothers' responsiveness and children's social engagement, or pivotal behavior. In this study, we attempted to determine whether children's pivotal behavior might also mediate the relationship between responsiveness and child development in a sample of 165 typically developing toddlers and their Taiwanese parents. Child development was assessed with a parent report measure of children's symbolic behavior. Parental responsiveness and children's pivotal behavior were assessed from observations of parent-child play. Results indicated that parental responsiveness was correlated with children's pivotal behavior, and that both of these variables were correlated with children's symbolic behavior. Structural equation models indicated that the relationship between responsiveness and children's symbolic behavior was fully mediated by children's pivotal behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

Developmental Precursors of Moral Disengagement and the Role of Moral Disengagement in the Development of Antisocial Behavior

Science.gov (United States)

Shaw, Daniel S.; Moilanen, Kristin L.

2010-01-01

The purpose of the study was to advance our understanding of the developmental precursors of Moral Disengagement (MD) and the role of MD in the development of antisocial behavior from early risk among an ethnically diverse sample of 187 low-income boys followed prospectively from ages 1.5 to 17. Results indicated associations between early rejecting parenting, neighborhood impoverishment, and child empathy and later MD. The link between some of these early constructs and later antisocial behavior was mediated by MD. Finally, in an exploratory path model both MD and biases in social information processing were found to mediate separate paths from early risk factors to later antisocial behavior. Results were partially consistent with the notion that adolescent MD was predicted by a combination of early family, neighborhood, and child risk factors, and that MD may be a mechanism underlying some boys' risk of antisocial behavior. PMID:19777337

Comparing the Developmental Genetics of Cognition and Personality over the Lifespan

Science.gov (United States)

Briley, Daniel A.; Tucker-Drob, Elliot M.

2015-01-01

Objective Empirical studies of cognitive ability and personality have tended to operate in isolation of one another. We suggest that returning to a unified approach to considering the development of individual differences in both cognition and personality can enrich our understanding of human development. Method We draw on previous meta-analyses of longitudinal, behavior genetic studies of cognition and personality across the lifespan, focusing particular attention on age trends in heritability and differential stability. Results Both cognition and personality are moderately heritable and exhibit large increases in stability with age; however, marked differences are evident. First, the heritability of cognition increases substantially with child age, while the heritability of personality decreases modestly with age. Second, increasing stability of cognition with age is overwhelmingly mediated by genetic factors, whereas increasing stability of personality with age is entirely mediated by environmental factors. Third, the maturational time-course of stability differs: Stability of cognition nears its asymptote by the end of the first decade of life, whereas stability of personality takes three decades to near its asymptote. Conclusions We discuss how proximal gene-environment dynamics, developmental processes, broad social contexts, and evolutionary pressures may intersect to give rise to these divergent patterns. PMID:26045299

Arguments from Developmental Order

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Richard eStöckle-Schobel

2016-05-01

Full Text Available In this article, I investigate a special type of argument regarding the role of development in theorising about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind – getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories.Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasising the importance of the early cognitive processes and arguments emphasising the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive development, and I will present some topics that also pertain to a full-fledged ‘philosophy of development’.

Developmental dyscalculia: a dysconnection syndrome?

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Kucian, Karin; Ashkenazi, Simone Schwizer; Hänggi, Jürgen; Rotzer, Stephanie; Jäncke, Lutz; Martin, Ernst; von Aster, Michael

2014-09-01

Numerical understanding is important for everyday life. For children with developmental dyscalculia (DD), numbers and magnitudes present profound problems which are thought to be based upon neuronal impairments of key regions for numerical understanding. The aim of the present study was to investigate possible differences in white matter fibre integrity between children with DD and controls using diffusion tensor imaging. White matter integrity and behavioural measures were evaluated in 15 children with developmental dyscalculia aged around 10 years and 15 matched controls. The main finding, obtained by a whole brain group comparison, revealed reduced fractional anisotropy in the superior longitudinal fasciculus in children with developmental dyscalculia. In addition, a region of interest analysis exhibited prominent deficits in fibres of the superior longitudinal fasciculus adjacent to the intraparietal sulcus, which is thought to be the core region for number processing. To conclude, our results outline deficient fibre projection between parietal, temporal and frontal regions in children with developmental dyscalculia, and therefore raise the question of whether dyscalculia can be seen as a dysconnection syndrome. Since the superior longitudinal fasciculus is involved in the integration and control of distributed brain processes, the present results highlight the importance of considering broader domain-general mechanisms in the diagnosis and therapy of dyscalculia.

Developmental trends in adaptive memory.

Science.gov (United States)

Otgaar, Henry; Howe, Mark L; Smeets, Tom; Garner, Sarah R

2014-01-01

Recent studies have revealed that memory is enhanced when information is processed for fitness-related purposes. The main objective of the current experiments was to test developmental trends in the evolutionary foundation of memory using different types of stimuli and paradigms. In Experiment 1, 11-year-olds and adults were presented with neutral, negative, and survival-related DRM word lists. We found a memory benefit for the survival-related words and showed that false memories were more likely to be elicited for the survival-related word lists than for the other lists. Experiment 2 examined developmental trends in the survival processing paradigm using neutral, negative, and survival-related pictures. A survival processing advantage was found for survival-related pictures in adults, for negative pictures in 11/12-year-olds, and for neutral pictures in 7/8-year-olds. In Experiment 3, 11/12-year-olds and adults had to imagine the standard survival scenario or an adapted survival condition (or pleasantness condition) that was designed to reduce the possibilities for elaborative processing. We found superior memory retention for both survival scenarios in children and adults. Collectively, our results evidently show that the survival processing advantage is developmentally invariant and that certain proximate mechanisms (elaboration and distinctiveness) underlie these developmental trends.

Unilateral implicit motor learning deficit in developmental dyslexia.

Science.gov (United States)

Yang, Yang; Hong-Yan, Bi

2011-02-01

It has been suggested that developmental dyslexia involves various literacy, sensory, motor skill, and processing speed deficits. Some recent studies have shown that individuals with developmental dyslexia exhibit implicit motor learning deficits, which may be related to cerebellar functioning. However, previous studies on implicit motor learning in developmental dyslexics have produced conflicting results. Findings from cerebellar lesion patients have shown that patients' implicit motor learning performance varied when different hands were used to complete tasks. This suggests that dyslexia may have different effects on implicit motor learning between the two hands if cerebellar dysfunction is involved. To specify this question, we used a one-handed version of a serial reaction time task to compare the performance of 27 Chinese children with developmental dyslexics with another 27 age-matched children without reading difficulties. All the subjects were students from two primary schools, Grades 4 to 6. The results showed that children with developmental dyslexic responded more slowly than nondyslexic children, and exhibited no implicit motor learning in the condition of left-hand response. In contrast, there was no significant difference in reaction time between two groups of children when they used the right hand to respond. This finding indicates that children with developmental dyslexia exhibited normal motor skill and implicit motor learning ability provided the right hand was used. Taken together, these results suggested that Chinese children with developmental dyslexia exhibit unilateral deficits in motor skill and implicit motor learning in the left hand. Our findings lend partial support to the cerebellar deficit theory of developmental dyslexia.

Developmental analytic view on narcissism

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Polona Matjan Štuhec

2009-07-01

Full Text Available Narcissistic pathology is connected to the pathology of the self. This article makes an overview of definitions of developmental analytic theories and stops with Kohut, Kernberg, Masterson, Auerbach and Mollon. The self is understood as a separate personality structure and has its own developmental line. Narcissism is a personality disorder that has its roots in preodipal developmental phases, mostly in the practicing and rapprochement subphase and in the oedipal phase as well. Recent research shows that the oedipal phase and the relation between the mother, the child's father (or her partner in general and the child is crucial for the maintenance of the pathological narcissism. Mothers who do not believe in a satisfying relationship with a man in general, keep the child in the dyadic position and do not support the development of the child's own identity.

Genome-wide survey and developmental expression mapping of zebrafish SET domain-containing genes.

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Xiao-Jian Sun

Full Text Available SET domain-containing proteins represent an evolutionarily conserved family of epigenetic regulators, which are responsible for most histone lysine methylation. Since some of these genes have been revealed to be essential for embryonic development, we propose that the zebrafish, a vertebrate model organism possessing many advantages for developmental studies, can be utilized to study the biological functions of these genes and the related epigenetic mechanisms during early development. To this end, we have performed a genome-wide survey of zebrafish SET domain genes. 58 genes total have been identified. Although gene duplication events give rise to several lineage-specific paralogs, clear reciprocal orthologous relationship reveals high conservation between zebrafish and human SET domain genes. These data were further subject to an evolutionary analysis ranging from yeast to human, leading to the identification of putative clusters of orthologous groups (COGs of this gene family. By means of whole-mount mRNA in situ hybridization strategy, we have also carried out a developmental expression mapping of these genes. A group of maternal SET domain genes, which are implicated in the programming of histone modification states in early development, have been identified and predicted to be responsible for all known sites of SET domain-mediated histone methylation. Furthermore, some genes show specific expression patterns in certain tissues at certain stages, suggesting the involvement of epigenetic mechanisms in the development of these systems. These results provide a global view of zebrafish SET domain histone methyltransferases in evolutionary and developmental dimensions and pave the way for using zebrafish to systematically study the roles of these genes during development.

Mediation Analysis with Multiple Mediators.

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VanderWeele, T J; Vansteelandt, S

2014-01-01

Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects through other pathways. The approaches proposed here accommodate exposure-mediator interactions and, to a certain extent, mediator-mediator interactions as well. The methods handle binary or continuous mediators and binary, continuous or count outcomes. When the mediators affect one another, the strategy of trying to assess direct and indirect effects one mediator at a time will in general fail; the approach given in this paper can still be used. A characterization is moreover given as to when the sum of the mediated effects for multiple mediators considered separately will be equal to the mediated effect of all of the mediators considered jointly. The approach proposed in this paper is robust to unmeasured common causes of two or more mediators.

Proteomic analysis of the signaling pathway mediated by the heterotrimeric G? protein Pga1 of Penicillium chrysogenum

OpenAIRE

Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J.; Z??iga-Le?n, Eduardo; Reyes-Vivas, Horacio; Fern?ndez, Francisco J.; Fierro, Francisco

2016-01-01

Background The heterotrimeric G? protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Results Penicillium chrysogenum mutants with ...

Developmental coordination disorder

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Developmental coordination disorder can lead to: Learning problems Low self-esteem resulting from poor ability at sports and teasing by other children Repeated injuries Weight gain as a result of not wanting to participate ...

Impact of Water Chemistry, Pipe Material and Stagnation on the Building Plumbing Microbiome.

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Pan Ji

Full Text Available A unique microbiome establishes in the portion of the potable water distribution system within homes and other buildings (i.e., building plumbing. To examine its composition and the factors that shape it, standardized cold water plumbing rigs were deployed at the treatment plant and in the distribution system of five water utilities across the U.S. Three pipe materials (copper with lead solder, CPVC with brass fittings or copper/lead combined pipe were compared, with 8 hour flush cycles of 10 minutes to simulate typical daily use patterns. High throughput Illumina sequencing of 16S rRNA gene amplicons was employed to profile and compare the resident bulk water bacteria and archaea. The utility, location of the pipe rig, pipe material and stagnation all had a significant influence on the plumbing microbiome composition, but the utility source water and treatment practices were dominant factors. Examination of 21 water chemistry parameters suggested that the total chlorine concentration, pH, P, SO42- and Mg were associated with the most of the variation in bulk water microbiome composition. Disinfectant type exerted a notably low-magnitude impact on microbiome composition. At two utilities using the same source water, slight differences in treatment approaches were associated with differences in rare taxa in samples. For genera containing opportunistic pathogens, Utility C samples (highest pH of 9-10 had the highest frequency of detection for Legionella spp. and lowest relative abundance of Mycobacterium spp. Data were examined across utilities to identify a true universal core, special core, and peripheral organisms to deepen insight into the physical and chemical factors that shape the building plumbing microbiome.

Development of Mentalizing and Communication: From Viewpoint of Developmental Cybernetics and Developmental Cognitive Neuroscience

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Itakura, Shoji

The ability to mentalize is essential for human socialization. Such ability is strongly related to communication. In this paper, I discuss the development of mentalizing and communication from the perspectives of a new idea, Developmental Cybernetics, and developmental cognitive neuroscience. Children only attributed intention to a robot when they saw it behaving as a human and displaying social signals such as eye gaze. The emergence of powerful new methods and tools, such as neuroimaging, now allows questions about mentalizing to resolved more directly than before.

Infant developmental milestones and adult intelligence

DEFF Research Database (Denmark)

Flensborg-Madsen, Trine; Mortensen, Erik Lykke

2015-01-01

Intelligence Scale (WAIS). Associations between motor developmental milestones and IQwere analysed bymultiple linear regression adjusting for potential confounding factors. Results: Later acquisition of infant developmental milestones was associated with lower subsequent IQ, and the majority of significant......Background: A number of studies suggest a positive association between faster infant motor development and intellectual function in childhood and adolescence. However, studies investigating the relationship between infant motor development and intelligence in adulthood are lacking. Aims......: To investigate whether age at achievement of 12 motor developmental milestones was associated with adult intelligence and to evaluate the influence of sex, parental social status, parity,mother's cigarette consumption in the last trimester, gestational age, birthweight, and birth length on this association...

Agrobacterium-mediated gene transfer in plants and biosafety considerations.

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Mehrotra, Shweta; Goyal, Vinod

2012-12-01

Agrobacterium, the natures' genetic engineer, has been used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer in plants is a highly efficient transformation process which is governed by various factors including genotype of the host plant, explant, vector, plasmid, bacterial strain, composition of culture medium, tissue damage, and temperature of co-cultivation. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques like floral or seedling infilteration, apical meristem transformation, and the pistil drip methods. Monocots have been comparatively difficult to transform by Agrobacterium. However, successful transformations have been reported in the last few years based on the adjustment of the parameters that govern the responses of monocots to Agrobacterium. A novel Agrobacterium transferred DNA-derived nanocomplex method has been developed which will be highly valuable for plant biology and biotechnology. Agrobacterium-mediated genetic transformation is known to be the preferred method of creating transgenic plants from a commercial and biosafety perspective. Agrobacterium-mediated gene transfer predominantly results in the integration of foreign genes at a single locus in the host plant, without associated vector backbone and is also known to produce marker free plants, which are the prerequisites for commercialization of transgenic crops. Research in Agrobacterium-mediated transformation can provide new and novel insights into the understanding of the regulatory process controlling molecular, cellular, biochemical, physiological, and developmental processes occurring during Agrobacterium-mediated transformation and also into a wide range of aspects on biological safety of transgenic crops to improve crop production to meet the demands of ever-growing world's population.

Current status of developmental neurotoxicity: regulatory view

DEFF Research Database (Denmark)

Hass, Ulla

2003-01-01

in the testing strategy for new and existing substances, and biocides. Hopefully, this will lead to an improved database for risk assessment of potential developmental neurotoxicants. However, the regulatory authorities and toxicologists will also be faced with the challenge that decisions have to be made......The need for developmental neurotoxicity testing has been recognized for decades and guidelines are available, as the USEPA guideline and the OECD draft TG 426. Regulatory testing of industrial chemicals for developmental neurotoxicity is required to some extent, especially for pesticides in the US....... Until recently, however, developmental neurotoxicity testing of industrial chemicals has not been a clear regulatory requirement in EU, probably due to the lack of an accepted OECD TG. The revised EU Technical Guidance Document for Risk Assessment (EU-TGD) has now included the OECD draft TG 426...

Developmental biology, the stem cell of biological disciplines

OpenAIRE

Gilbert, Scott F.

2017-01-01

Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines.” Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, ...

A Critical Pragmatism: Marcuse, Adorno, and Peirce on the Artificial Stagnation of Individual and Social Development in Advanced Industrial Societies

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Clancy Smith

2009-12-01

Full Text Available This paper will analyze the effects advanced industrial societies have on individual and social development through the eyes of Marcuse’s One-Dimensional Man and the moral consequences of such artificial stagnation through Adorno’s lectures on The Problems of Moral Philosophy. Because such an investigation necessarily brings us into the realm of social psychology, we will turn to the social psychological tradition at the heart of American pragmatism, a target for critical theorists who are often antagonistic to the entire tradition. We will endeavor to advance two alternate readings of the work of C.S. Peirce, arguing that although one type of pragmatism may be justly attacked by critical theorists, there is another, I argue, more critical manifestation of pragmatic human development, that requires the type of autonomy-infused, open-ended development that Marcuse champions. Moreover, I will argue that Peirce’s seminal essay “The Fixation of Belief” anticipated many of Marcuse’s critiques of advanced industrial societies by nearly ninety years.

Effects and mechanisms of Shaofu-Zhuyu decoction and its major bioactive component for Cold - Stagnation and Blood - Stasis primary dysmenorrhea rats.

Science.gov (United States)

Huang, Xiaochen; Su, Shulan; Duan, Jin-Ao; Sha, Xiuxiu; Zhu, Kavin Yue; Guo, Jianming; Yu, Li; Liu, Pei; Shang, Erxin; Qian, Dawei

2016-06-20

Traditional Chinese medicine (TCM) is used under the guidance of the theory of traditional Chinese medical sciences in clinical application. The Chinese herbal formula, Shaofu Zhuyu decoction (SFZYD), is considered as an effective prescription for treating Cold - Stagnation and Blood - Stasis (CSBS) primary dysmenorrhea. The previous studies showed the SFZYD exhibited significant anti-inflammation and analgesic effect. In this present study the metabolomics of CSBS primary dysmenorrhea diseased rats and the cytokine transcription in PHA stimulated-PBMC were investigated to explore the effects and mechanisms. Explore a valuable insight into the effects and mechanisms of SFZYD on Cold - Stagnation and Blood - Stasis primary dysmenorrhea rats. We established CSBS primary dysmenorrhea diseased rats according the clinical symptoms. A targeted tandem mass spectrometry (MS/MS)-based metabolomic platform was used to evaluate the metabolic profiling changes and the intervention effects by SFZYD. The PBMC cell was adopted to explore the mechanisms by analyzing the signaling pathway evaluated by expression of inflammatory cytokines, c-jun and c-fos and corresponding phosphorylation levels. Estradiol, oxytocin, progesterone, endothelin, β-endorphin and PGF2α were restored back to the normal level after the treatment of SFZYD. Total twenty-five metabolites (10 in plasma and 15 in urine), up-regulated or down-regulated, were identified. These identified biomarkers underpinning the metabolic pathway including pentose and glucuronate interconversions, steroid hormone biosynthesis, and glycerophospholipid metabolism are disturbed in model rats. Among these metabolites, twenty one potential biomarkers were regulated after SFZYD treated. The compound of paeoniflorin, a major bioactive compound in SFZYD, was proved to regulate the MAPK signaling pathway by inhibiting the expression of IL-1β, IL-2, IL-10, IL-12, TNFα, INFγ, c-jun and c-fos in PHA stimulated-PBMC. These findings

The diversification of developmental biology.

Science.gov (United States)

Crowe, Nathan; Dietrich, Michael R; Alomepe, Beverly S; Antrim, Amelia F; ByrneSim, Bay Lauris; He, Yi

2015-10-01

In the 1960s, "developmental biology" became the dominant term to describe some of the research that had previously been included under the rubrics of embryology, growth, morphology, and physiology. As scientific societies formed under this new label, a new discipline took shape. Historians, however, have a number of different perspectives on what changes led to this new field of developmental biology and how the field itself was constituted during this period. Using the General Embryological Information Service, a global index of post-World War II development-related research, we have documented and visualized significant changes in the kinds of research that occurred as this new field formed. In particular, our analysis supports the claim that the transition toward developmental biology was marked by a growth in new topics and forms of research. Although many historians privilege the role of molecular biology and/or the molecularization of biology in general during this formative period, we have found that the influence of molecular biology is not sufficient to account for the wide range of new research that constituted developmental biology at the time. Overall, our work creates a robust characterization of the changes that occurred with regard to research on growth and development in the decades following World War II and provides a context for future work on the specific drivers of those changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Working memory mediates the effects of gestational age at birth on expressive language development in children.

Science.gov (United States)

Riva, Valentina; Cantiani, Chiara; Dionne, Ginette; Marini, Andrea; Mascheretti, Sara; Molteni, Massimo; Marino, Cecilia

2017-07-01

This study tested the role of temporary memory, measured by phonological short-term memory (pSTM) and verbal working memory (vWM), as a mediator of the effect of 3 putative risk factors (i.e., socioeconomic status, home literacy environment, birth gestational age) upon expressive and receptive language. A community-based sample of 646 Italian children aged 6-11 years was assessed with a comprehensive battery of language and cognitive tests. A mediation analysis was used to examine whether memory mediates environmental/biological effects on language. The results demonstrated a developmental cascade of effects, whereby the duration of pregnancy drives vWM functioning that, in turn, may affect expressive linguistic outcome Conclusion: Treatments focused on vWM, specifically to preterm children, may improve their language development, with enduring consequences on educational and psychosocial outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The effects of early positive parenting and developmental delay status on child emotion dysregulation.

Science.gov (United States)

Norona, A N; Baker, B L

2017-02-01

Emotion regulation has been identified as a robust predictor of adaptive functioning across a variety of domains (Aldao et al. ). Furthermore, research examining early predictors of competence and deficits in ER suggests that factors internal to the individual (e.g. neuroregulatory reactivity, behavioural traits and cognitive ability) and external to the individual (e.g. caregiving styles and explicit ER training) contribute to the development of ER (Calkins ). Many studies have focused on internal sources or external sources; however, few have studied them simultaneously within one model, especially in studies examining children with developmental delays (DD). Here, we addressed this specific research gap and examined the contributions of one internal factor and one external factor on emotion dysregulation outcomes in middle childhood. Specifically, our current study used structural equation modelling (SEM) to examine prospective, predictive relationships between DD status, positive parenting at age 4 years and child emotion dysregulation at age 7 years. Participants were 151 families in the Collaborative Family Study, a longitudinal study of young children with and without DD. A positive parenting factor was composed of sensitivity and scaffolding scores from mother-child interactions at home and in the research centre at child age 4 years. A child dysregulation factor was composed of a dysregulation code from mother-child interactions and a parent-report measure of ER and lability/negativity at age 7 years. Finally, we tested the hypothesis that positive parenting would mediate the relationship between DD and child dysregulation. Mothers of children with DD exhibited fewer sensitive and scaffolding behaviours compared with mothers of typically developing children, and children with DD were more dysregulated on all measures of ER. SEM revealed that both DD status and early positive parenting predicted emotion dysregulation in middle childhood. Furthermore

Developmental toxicity of engineered nanomaterials

DEFF Research Database (Denmark)

Hougaard, Karin S.; Hansen, Jitka S.; Jackson, Petra

2016-01-01

Study of air pollution indicates that minute particles may adversely interfere with pregnancy and fetal development. As engineering of nanoparticles have emerged, so has concern that these might interfere with reproductive and developmental functions. This is because nanotechnology may potentially...... increase the overall particle burden in air and introduce particles with novel characteristics and surface reactivity. To evaluate safety for pregnant women, we have studied developmental toxicity of engineered nanoparticles (ENPs), following exposure of pregnant mice by inhalation (ENPs of titanium...

MHD stagnation point flow and heat transfer of a nanofluid over a permeable nonlinear stretching/shrinking sheet with viscous dissipation effect

Science.gov (United States)

Jusoh, Rahimah; Nazar, Roslinda

2018-04-01

The magnetohydrodynamic (MHD) stagnation point flow and heat transfer of an electrically conducting nanofluid over a nonlinear stretching/shrinking sheet is studied numerically. Mathematical modelling and analysis are attended in the presence of viscous dissipation. Appropriate similarity transformations are used to reduce the boundary layer equations for momentum, energy and concentration into a set of ordinary differential equations. The reduced equations are solved numerically using the built in bvp4c function in Matlab. The numerical and graphical results on the effects of various parameters on the velocity and temperature profiles as well as the skin friction coefficient and the local Nusselt number are analyzed and discussed in this paper. The study discovers the existence of dual solutions for a certain range of the suction parameter. The conducted stability analysis reveals that the first solution is stable and feasible, while the second solution is unstable.

Low functional programming of renal AT2R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure.

Science.gov (United States)

Ao, Ying; Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na; Li, Bin; Yang, Shuailong; Xia, Liping; Wu, Yong; Wang, Linlong; He, Zheng; Wang, Hui

2015-09-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT2R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT1aR)/AT2R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT2R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT2R might mediate the developmental origin of adult glomerulosclerosis. Copyright © 2015. Published by Elsevier Inc.

Future Expectations, Attitude Toward Violence, and Bullying Perpetration During Early Adolescence: A Mediation Evaluation.

Science.gov (United States)

Stoddard, Sarah A; Varela, Jorge J; Zimmerman, Marc A

2015-01-01

Hopeful future expectations have been linked to positive developmental outcomes in adolescence; however, the association between future expectations and bullying perpetration has received less attention. We examined the relationship between future expectations and physical and relational bullying perpetration and tested a mediation model that linked future expectations with bullying through attitude toward violence. Structural equation modeling was used to examine the relationship between future expectations and bullying perpetration (relational and physical) and to test whether these relationships were mediated by attitude toward violence in a sample of U.S. seventh-grade students (Mage = 12.86 years, N = 196, 60% female, 46% African American). Attitude toward violence fully mediated the relationship between future expectations and physical bullying (indirect effects = -0.08, 95% CI [-0.15, -0.01], R = .17). The relationship between future expectations and relational bullying was partially mediated by attitudes toward violence (indirect effects = -0.07, 95% CI [-0.14, -0.002], R = .20). Our findings suggest that future expectations can play a role in reducing attitude toward violence and physical and relational bullying perpetration among youth. Interventions that help support the development of future goals and aspirations could play a vital role in bullying prevention efforts.

Large amplitude oscillation of a boiling bubble growing at a wall in stagnation flow

International Nuclear Information System (INIS)

Geld, C.W.M. van der; Berg, R. van de; Peukert, P.

2009-01-01

A boiling bubble is created on an artificial site that is part of a bubble generator that is mounted at the center of a pipe. Downflow of water impinges on the bubble generator and creates a stagnation flow above the artificial cavity. Stable axisymmetric elongation in the direction away from the wall and multiple shape oscillation cycles are observed. The time of growth and attachment is typically of the order of 250 ms. Amongst the length scales that characterize the bubble shape is the radius of curvature of the upper part of the bubble, R. The period of oscillation, T, is strongly dependent on time, as is R. The parameters C and m in the defining equation T = C R m √(ρL/σ) have been determined by fitting to data of more than 100 bubbles. For each operating condition, the same values of C and m have been found. The value of m is 1.49 ± 0.02, which is explained from the continuous growth of the bubble and from the relation to the period of oscillation of a free bubble deforming in the fundamental mode corresponding to the third Legendre Polynomial. For the latter, R is the radius of the volume-equivalent sphere, R 0 , and C is √12, while for attached boiling bubbles C is found to amount 1.9√12. The difference is easily explained from the continuous growth, difference in definition, finite amplitude oscillation and proximity of the wall. (author)

Large amplitude oscillation of a boiling bubble growing at a wall in stagnation flow

Energy Technology Data Exchange (ETDEWEB)

Geld, C.W.M. van der; Berg, R. van de; Peukert, P. [Eindhoven University of Technology, Eindhoven (Netherlands). Faculty of Mechanical Engineering], e-mail: C.W.M._v.d.Geld@tue.nl

2009-07-01

A boiling bubble is created on an artificial site that is part of a bubble generator that is mounted at the center of a pipe. Downflow of water impinges on the bubble generator and creates a stagnation flow above the artificial cavity. Stable axisymmetric elongation in the direction away from the wall and multiple shape oscillation cycles are observed. The time of growth and attachment is typically of the order of 250 ms. Amongst the length scales that characterize the bubble shape is the radius of curvature of the upper part of the bubble, R. The period of oscillation, T, is strongly dependent on time, as is R. The parameters C and m in the defining equation T = C R{sup m} {radical}({rho}L/{sigma}) have been determined by fitting to data of more than 100 bubbles. For each operating condition, the same values of C and m have been found. The value of m is 1.49 {+-} 0.02, which is explained from the continuous growth of the bubble and from the relation to the period of oscillation of a free bubble deforming in the fundamental mode corresponding to the third Legendre Polynomial. For the latter, R is the radius of the volume-equivalent sphere, R{sub 0}, and C is {radical}12, while for attached boiling bubbles C is found to amount 1.9{radical}12. The difference is easily explained from the continuous growth, difference in definition, finite amplitude oscillation and proximity of the wall. (author)

Developmental neurotoxicity of Propylthiouracil in rats

DEFF Research Database (Denmark)

Petersen, Marta Axelstad; Hansen, P.; Christiansen, S.

2007-01-01

early in pregnancy may cause adverse effects on the offspring. This has led to increased concern about thyroid hormone disrupting chemicals (TDCs) in our environment. We have studied how developmental exposure to the known antithyroid agent propylthiouracil (PTU) affects the development of rat pups...... behaviour and hearing function. This supports that exposure to TDC's in general may cause long-lasting developmental neurotoxicity....

Unpacking developmental local government using Soft Systems ...

African Journals Online (AJOL)

Unpacking developmental local government using Soft Systems Methodology and MCDA tools. L Scott. Abstract. This paper presents two different analytical approaches that may be useful in developing an understanding of developmental local government (DLG). DLG implies a significant commitment with respect to ...

Rethinking developmental toxicity testing: Evolution or revolution?

NARCIS (Netherlands)

Scialli, Anthony R; Daston, George; Chen, Connie; Coder, Prägati S; Euling, Susan Y; Foreman, Jennifer; Hoberman, Alan M; Hui, Julia; Knudsen, Thomas; Makris, Susan L; Morford, LaRonda; Piersma, Aldert H; Stanislaus, Dinesh; Thompson, Kary E

2018-01-01

Current developmental toxicity testing adheres largely to protocols suggested in 1966 involving the administration of test compound to pregnant laboratory animals. After more than 50 years of embryo-fetal development testing, are we ready to consider a different approach to human developmental

Are Students with Developmental Dyslexia Neurologically Different?

Science.gov (United States)

Goldsmith-Phillips, Josephine

1994-01-01

Reviews the controversy over a biological basis for developmental dyslexia and illustrates it with two case studies of junior high school students. Reviews neurological evidence for developmental dyslexia, and proposes seven signs characteristic of reading disability that may qualify as dyslexia. (SR)

Risk factors of ophthalmic disorders in children with developmental delay

DEFF Research Database (Denmark)

Sandfeld, L.N.; Jensen, H.; Skov, L.

2008-01-01

PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12......PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12...

Young Children’s Developmental Ecologies and Kindergarten Readiness

Science.gov (United States)

Mollborn, Stefanie

2016-01-01

Children enter the crucial transition to school with sociodemographic disparities firmly established. Domain-specific research (e.g., on poverty and family structure) has shed light on these disparities, but we need broader operationalizations of children’s environments to explain them. Building on existing theory, this study articulates the concept of developmental ecology—those interrelated features of a child’s proximal environment that shape development and health. Developmental ecology links structural and demographic factors with interactional, psychological, and genetic factors. Using the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), this study conducts latent class analyses to identify how 41 factors from three domains—namely, household resources, health risks, and ecological changes—cluster within children as four overarching developmental ecologies. Because it documents how numerous factors co-occur within children, this method allows an approximation of their lived environments. Findings illuminate powerful relationships between race/ethnicity, parental age, socioeconomic background, and nativity and a child’s developmental ecology, as well as associations between developmental ecology and kindergarten cognition, behavior, and health. Developmental ecology represents a major pathway through which demographic characteristics shape school readiness. Because specific factors have different implications depending on the ecologies in which they are embedded, findings support the usefulness of a broad ecological approach. PMID:27873222

Co-Occurrence of Developmental Disorders: The Case of Developmental Dyscalculia

Science.gov (United States)

Rubinsten, Orly

2009-01-01

Five to seven percent of children experience severe difficulties in learning mathematics and/or reading. Current trials that are focused on identifying biological markers suggest that these learning disabilities, known as Developmental Dyscalculia (DD) and Dyslexia (for reading), are due to underlying brain dysfunctions. One ongoing controversy…

Biomarkers of adult and developmental neurotoxicity

International Nuclear Information System (INIS)

Slikker, William; Bowyer, John F.

2005-01-01

Neurotoxicity may be defined as any adverse effect on the structure or function of the central and/or peripheral nervous system by a biological, chemical, or physical agent. A multidisciplinary approach is necessary to assess adult and developmental neurotoxicity due to the complex and diverse functions of the nervous system. The overall strategy for understanding developmental neurotoxicity is based on two assumptions: (1) significant differences in the adult versus the developing nervous system susceptibility to neurotoxicity exist and they are often developmental stage dependent; (2) a multidisciplinary approach using neurobiological, including gene expression assays, neurophysiological, neuropathological, and behavioral function is necessary for a precise assessment of neurotoxicity. Application of genomic approaches to developmental studies must use the same criteria for evaluating microarray studies as those in adults including consideration of reproducibility, statistical analysis, homogenous cell populations, and confirmation with non-array methods. A study using amphetamine to induce neurotoxicity supports the following: (1) gene expression data can help define neurotoxic mechanism(s) (2) gene expression changes can be useful biomarkers of effect, and (3) the site-selective nature of gene expression in the nervous system may mandate assessment of selective cell populations

NIDCAP and developmental care

Directory of Open Access Journals (Sweden)

Dominique Haumont

2014-06-01

Full Text Available Perinatal mortality in very low birth weight infants has dramatically decreased during the last decades. However, 15-25% of these infants will show neurodevelopmental impairment later on. The aim of implementing early developmental care (EDC, emerged as a new field in neonatology, is to create an intervention program designed to provide support for optimal neurobehavioral development during this highly vulnerable period of brain growth. The theoretical framework, which underlies the approach, is supported by research in different scientific fields, including neuroscience, psychology, medicine and nursing. EDC utilizes a range of medical and nursing interventions that aim to decrease the stress of preterm neonates in neonatal intensive care units (NICUs. The Neonatal Individualized Developmental Care Assessment Program (NIDCAP is an integrated and holistic form of family-centered developmental care. Changing the traditional NICU towards an EDC-NICU includes training nursing and medical staff, investing in their quality and most importantly keeping parents in proximity to the infants. The new challenge of modern neonatology is to restore the mother-infant dyad applying “couplet care” starting at birth until discharge. Most of the European NICUs apply some elements of EDC, but it is more consistent in northern Europe. The development of NIDCAP training centers in Europe demonstrates the evolution of care. It is likely that future research and intervention programs will optimize our practices. Developmental care could prove to be an important recent step in improving outcome in extremely preterm neonates. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in Neonatology Guest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Prostaglandin-mediated recovery from bacteremia delays larval development in fall armyworm, Spodoptera frugiperda.

Science.gov (United States)

Zhang, Lei; Ringbauer, Joseph A; Goodman, Cynthia L; Reall, Tamra; Jiang, Xing-Fu; Stanley, David

2018-04-01

Insect immunity includes a surveillance system that detects and signals infections, coupled with hemocytic and humoral immune functions. These functions are signaled and coordinated by several biochemicals, including biogenic amines, insect cytokines, peptides, and prostaglandins (PGs). The actions of these mediators are coordinated within cells by various forms of cross-talk among the signaling systems and they result in effective reactions to infection. While this is well understood, we lack information on how immune-mediated recovery influences subsequent juvenile development in surviving insects. We investigated this point by posing the hypothesis that PG signaling is necessary for larval recovery, although the recovery imposes biological costs, registered in developmental delays and failures in surviving individuals. Here, we report that nodulation responses to infections by the bacterium, Serratia marcescens, increased over time up to 5 h postinfection, with no further nodulation; it increased in a linear manner with increasing bacterial dosages. Larval survivorship decreased with increasing bacterial doses. Treating larvae with the PG-biosynthesis inhibitor, indomethacin, led to sharply decreased nodulation reactions to infection, which were rescued in larvae cotreated with indomethacin and the PG-precursor, arachidonic acid. Although nodulation was fully rescued, all bacterial challenged larvae suffered reduced survivorship compared to controls. Bacterial infection led to reduced developmental rates in larvae, but not pupae. Adult emergence from pupae that developed from experimental larvae was also decreased. Taken together, our data potently bolster our hypothesis. © 2018 Wiley Periodicals, Inc.

The Application of Intentional Subjective Properties and Mediated Communication Tools to Software Agents in Online Disputes Resolution Environments

Directory of Open Access Journals (Sweden)

Renzo Gobbin

2004-11-01

Full Text Available This paper examines the use of subjective properties in modeling an architecture for cooperative agents using Agent Communication Language (ACL that is used as a mediating tool for cooperative communication activities between and within software agents. The role that subjective and objective properties have in explaining and modeling agent internalization and externalization of ACL messages is investigated and related to Vygotsky’s developmental learning theories such as Mediated Activity Theory. A novel agent architecture ALMA (Agent Language Mediated Activity based on the integration of agents’ subjective and objective properties within an agent communication activity framework will be presented. The relevance of software agents subjective properties in modeling applications such as e-Law Online Dispute Resolution for e-business contractual arrangements using natural language subject/object relation in their communication patterns will be discussed.

Reproductive and developmental toxicology

National Research Council Canada - National Science Library

Gupta, Ramesh C

2011-01-01

.... Reproductive and Developmental Toxicology is a comprehensive and authoritative resource providing the latest literature enriched with relevant references describing every aspect of this area of science...

Psychological Resources of Adults with Developmental Dyslexia

Science.gov (United States)

Lockiewicz, Marta; Bogdanowicz, Katarzyna M.; Bogdanowicz, Marta

2014-01-01

The aim of our study was to describe specific psychological resources of adults with developmental dyslexia and compare them with psychological resources of adults without developmental dyslexia. Potential differences were analyzed in visual-spatial, creative, and motivational abilities. No evidence was found for either creative, or visuospatial…

The two forms of capitalism: developmentalism and economic liberalism

Directory of Open Access Journals (Sweden)

LUIZ CARLOS BRESSER-PEREIRA

Full Text Available ABSTRACT This paper argues that the state and the market are the main institutions regulating capitalism, and, correspondingly, that the form of the economic and political coordination of capitalism will be either developmental or liberal. It defines the developmental state, relates it to the formation of a developmental class coalition, and notes that capitalism was born developmental in its mercantilist phase, turned liberal in the nineteenth century, and, after 1929, became once again developmental, but, now, democratic and progressive. All industrial and capitalist revolutions took place within the framework of developmentalism, whereby the state coordinates the non-competitive sector of the economy and the five macroeconomic prices (which the market is unable to make “right”, while the market coordinates the competitive sector. In the 1970s, a crisis opened the way for a short-lived and reactionary form of capitalism, neoliberalism or rentier-financier capitalism. Since the 2008 Global Financial Crisis, the neoliberal hegemony has come to an end, and we are now experiencing a period of transition.

Thermophysical analysis for three-dimensional MHD stagnation-point flow of nano-material influenced by an exponential stretching surface

Science.gov (United States)

Ur Rehman, Fiaz; Nadeem, Sohail; Ur Rehman, Hafeez; Ul Haq, Rizwan

2018-03-01

In the present paper a theoretical investigation is performed to analyze heat and mass transport enhancement of water-based nanofluid for three dimensional (3D) MHD stagnation-point flow caused by an exponentially stretched surface. Water is considered as a base fluid. There are three (3) types of nanoparticles considered in this study namely, CuO (Copper oxide), Fe3O4 (Magnetite), and Al2O3 (Alumina) are considered along with water. In this problem we invoked the boundary layer phenomena and suitable similarity transformation, as a result our three dimensional non-linear equations of describing current problem are transmuted into nonlinear and non-homogeneous differential equations involving ordinary derivatives. We solved the final equations by applying homotopy analysis technique. Influential outcomes of aggressing parameters involved in this study, effecting profiles of temperature field and velocity are explained in detail. Graphical results of involved parameters appearing in considered nanofluid are presented separately. It is worth mentioning that Skin-friction along x and y-direction is maximum for Copper oxide-water nanofluid and minimum for Alumina-water nanofluid. Result for local Nusselt number is maximum for Copper oxide-water nanofluid and is minimum for magnetite-water nanofluid.

General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt

KAUST Repository

Lacoh, Claudia Marvine

2013-03-26

BackgroundThe developmental transition from depolarizing to hyperpolarizing γ-aminobutyric acid-mediated neurotransmission is primarily mediated by an increase in the amount of the potassium-chloride cotransporter KCC2 during early postnatal life. However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study was to explore how these drugs affect KCC2 expression during the brain growth spurt.MethodsWistar rat pups were exposed to either a single dose or 6 h of midazolam, propofol, or ketamine anaesthesia at postnatal days 0, 5, 10, or 15. KCC2 expression was assessed using immunoblotting, immunohistochemistry, or quantitative polymerase chain reaction analysis up to 3 days post-exposure in the medial prefrontal cortex.ResultsThere was a progressive and steep increase in the expression of KCC2 between birth and 2 weeks of age. Exposure to midazolam, propofol, or ketamine up to 6 h at any investigated stages of the brain growth spurt did not influence the expression of this cotransporter protein.ConclusionI.V. general anaesthetics do not seem to influence developmental expression of KCC2 during the brain growth spurt. © 2013 © The Author [2013].

Text (Oral) Reading Fluency as a Construct in Reading Development: An Investigation of Its Mediating Role for Children from Grades 1 to 4

Science.gov (United States)

Kim, Young-Suk Grace; Wagner, Richard K.

2015-01-01

In the present study we investigated a developmentally changing role of text reading fluency in mediating the relations of word reading fluency and listening comprehension to reading comprehension. We addressed this question by using longitudinal data from Grades 1 to 4 and employing structural equation models. Results showed that the role of text…

Developmental orthopaedic diseases in foals

International Nuclear Information System (INIS)

Şİrİn, Özlem; Alkan, Zeki

2010-01-01

Developmental Orthopaedic Diseases (DOD) is seen frequently in horses which completed their maturity. Osteochondrosis, physitis, angular limb deformities, flexural deformities, juvenil arthritis, cervical vertebral anomalies, cuboidal bone abnormalities are problems investigated under Developmental Orthopaedic Diseases title. This diseases can develop single or some together in fast growing, heavy animals (especially Arabian and English Thoroughbreds). Multifactorial causes of this diseases etiopathogenesis can be listed as genetic predisposition, trauma, nutrition, vitamins/minerals and endocrine disorders. But the exact causes of these diseases are not known. In this review detailed information are given about the diseases mentioned above

Relationships between levels of motor coordination, attention and physical activity in children: The mediation model

Directory of Open Access Journals (Sweden)

Jakub Kokštejn

2012-12-01

Full Text Available BACKGROUND: Current findings suggest that physical activity of children with developmental difficulties may be limited by low level of motor coordination. Motor difficulties are often connected with children suffering from attention deficit disorder. OBJECTIVE: The aim of the study was to find out the level of physical activity (PA in older school-age children with motor difficulties (MD in comparison with children without MD and to reveal possible mediate impact on attention between the level of motor skills and PA in children of this age. METHODS: Participants were divided into two groups: 15 children with MD (age 13.7 ± 1.6 years and 27 children without MD (age 13.3 ± 1.4 years. Motor functions were assessed by means of test battery MABC-2, weekly physical activity by means of Actigraph accelerometer and attention by both d2 and numeric square tests. To estimate the mediation of the attention level we have used Baron's & Kenny's (1986 analysis. RESULTS: In most of the indicators of PA, children with MD reached lower value than those without MD. The differences of statistical significance were found in the number of steps per week and weekdays (d = 0.50 and 0.64 respectively and in PA of a very high intensity (d =2 .00 in boys with and without MD. In girls with MD we have found out significantly less time spent in vigorous intensity PA (d = 0.86. The study results support the hypothesis of developmental motor deficits to be a risk factor for PA in older school-age children. Significant mediation effect of concentration of attention in the relationship between the level of motor skills and PA was observed in three cases - in the relationship between gross motor skills on the one hand, and energy expenditure per week and weekdays, and vigorous intensity PA per week on the other. The amount of mediation effect of attention concentration ranged between 12-22%. CONCLUSION: The study has indicated that children's participation in PA can be

Stable isotopic fractionation, climate change and episodic stagnation in the eastern Mediterranean during the late Quaternary

Energy Technology Data Exchange (ETDEWEB)

Vergnaud-Grazzini, C [Laboratoire de Geologie Dynamique, Paris (France); Ryan, W B.F. [Columbia Univ., Palisades, NY (USA). Lamont-Doherty Geological Observatory; Cita, M B [Milan Univ. (Italy)

1977-11-01

Fluctuations in the delta/sup 18/O composition of planktonic foraminifers in eastern Mediterranean piston cores indicate cycles with amplitudes much greater than those which can be attributed alone to global ice-volume changes. Isotopic values become markedly negative within lithostratigraphic levels characterized by the apparition of organic-rich sapropels. These owe their origin to the development of euxinic bottom water during episodes of basin-wide stagnation. The depletion of delta/sup 18/O in many of the sapropels is accompanied by the occurrence of poorly diversified planktonic faunas, and both phenomena are attributed to a strong dilution of the local eastern Mediterranean surface water mass by a combination of glacial run off from large continental ice sheets and by an important increase of regional precipitation synchronous with the transition from pleniglacial to kataglacial climate. Although sapropel accumulation occurs generally during intervals of warming of the Mediterranean region as determined from a quantitative evaluation of planktonic foraminiferal assemblages, the pre-125,000 years, local warming of eastern Mediterranean surface water lagged the acme of glacial melting by up to 15,000 years. Climatic and isotopic cycles are correlative within the eastern Mediterranean for lateral distances in excess of 1000 km and, except for amplitude and phase, they are in most aspects remarkably similar to those recorded in the equatorial Pacific and Caribbean.

Comparative genomic analysis of Drosophila melanogaster and vector mosquito developmental genes.

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Susanta K Behura

Full Text Available Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1 are components of developmental signaling pathways, 2 regulate fundamental developmental processes, 3 are critical for the development of tissues of vector importance, 4 function in developmental processes known to have diverged within insects, and 5 encode microRNAs (miRNAs that regulate developmental transcripts in Drosophila. While most fruit fly developmental genes are conserved in the three vector mosquito species, several genes known to be critical for Drosophila development were not identified in one or more mosquito genomes. In other cases, mosquito lineage-specific gene gains with respect to D. melanogaster were noted. Sequence analyses also revealed that numerous repetitive sequences are a common structural feature of Drosophila and mosquito developmental genes. Finally, analysis of predicted miRNA binding sites in fruit fly and mosquito developmental genes suggests that the repertoire of developmental genes targeted by miRNAs is species-specific. The results of this study provide insight into the evolution of developmental genes and processes in dipterans and other arthropods, serve as a resource for those pursuing analysis of mosquito development, and will promote the design and refinement of functional analysis experiments.

Delaying Developmental Mathematics: The Characteristics and Costs

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Johnson, Marianne; Kuennen, Eric

2004-01-01

This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

Essential Role of Culture in Developmental Psychology

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Miller, Joan G.

2005-01-01

This chapter argues for the essential role of culture in forming the basic constructs and theories of developmental psychology. The case is made for the need to overcome the cultural insularity of core developmental concepts and methods in order to create a psychology that is more truly universal.

Comorbid psychopathology and stress mediate the relationship between autistic traits and repetitive behaviours in adults with autism.

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García-Villamisar, D; Rojahn, J

2015-02-01

Comorbid psychopathology and stress were considered possible mediators that may explain the relationship between some autistic traits and repetitive behaviours. The current study sought to examine the mediational effects of comorbid psychopathology, executive dysfunctions and stress in the relationship between some autistic traits and repetitive behaviours. A battery of questionnaires including measures of autistic traits, repetitive behaviours, stress, executive dysfunctions and comorbid psychopathology were administered to a sample of adults with autism and intellectual disabilities (n = 43). We found that when taken as set dimensions of comorbidity, dysexecutive functioning and stress mediated or explained the effects of autistic symptoms on repetitive behaviour. The total model explained 60% of the variation in repetitive behaviours (R = 0.60; F = 13.64, P autism, while executive functioning did not contribute to that relationship. © 2013 2013 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Unsteady separated stagnation-point flow and heat transfer of a viscous fluid over a moving flat surface

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Dholey, S.

2018-04-01

In this paper, we have investigated numerically the laminar unsteady separated stagnation-point flow and heat transfer of a viscous fluid over a moving flat surface in the presence of a time dependent free stream velocity which causes the unsteadiness of this flow problem. The plate is assumed to move in the same or opposite direction of the free stream velocity. The flow is therefore governed by the velocity ratio parameter λ (ratio of the plate velocity to the free stream velocity) and the unsteadiness parameter β. When the plate surface moves in the same direction of the free stream velocity (i.e., when λ > 0), the solution of this flow problem continues for any given value of β. On the other hand, when they move in opposite directions (i.e., when λ heat transfer analysis is that for a given value of λ(= 0), first the heat transfer rate increases with the increase of the Prandtl number Pr and after attaining a maximum value, it decreases and finally tends to be zero for large values of Pr depending upon the values of β > 0. On the contrary, for a given value of β(≤ 0), the rate of heat transfer increases consistently with the increase of Pr.

Fetal functional brain age assessed from universal developmental indices obtained from neuro-vegetative activity patterns.

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Dirk Hoyer

Full Text Available Fetal brain development involves the development of the neuro-vegetative (autonomic control that is mediated by the autonomic nervous system (ANS. Disturbances of the fetal brain development have implications for diseases in later postnatal life. In that context, the fetal functional brain age can be altered. Universal principles of developmental biology applied to patterns of autonomic control may allow a functional age assessment. The work aims at the development of a fetal autonomic brain age score (fABAS based on heart rate patterns. We analysed n = 113 recordings in quiet sleep, n = 286 in active sleep, and n = 29 in active awakeness from normals. We estimated fABAS from magnetocardiographic recordings (21.4-40.3 weeks of gestation preclassified in quiet sleep (n = 113, 63 females and active sleep (n = 286, 145 females state by cross-validated multivariate linear regression models in a cross-sectional study. According to universal system developmental principles, we included indices that address increasing fluctuation range, increasing complexity, and pattern formation (skewness, power spectral ratio VLF/LF, pNN5. The resulting models constituted fABAS. fABAS explained 66/63% (coefficient of determination R(2 of training and validation set of the variance by age in quiet, while 51/50% in active sleep. By means of a logistic regression model using fluctuation range and fetal age, quiet and active sleep were automatically reclassified (94.3/93.1% correct classifications. We did not find relevant gender differences. We conclude that functional brain age can be assessed based on universal developmental indices obtained from autonomic control patterns. fABAS reflect normal complex functional brain maturation. The presented normative data are supplemented by an explorative study of 19 fetuses compromised by intrauterine growth restriction. We observed a shift in the state distribution towards active awakeness. The lower WGA

Social Adversity and Antisocial Behavior: Mediating Effects of Autonomic Nervous System Activity.

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Fagan, Shawn E; Zhang, Wei; Gao, Yu

2017-11-01

The display of antisocial behaviors in children and adolescents has been of interest to criminologists and developmental psychologists for years. Exposure to social adversity is a well-documented predictor of antisocial behavior. Additionally, measures of autonomic nervous system (ANS) activity, including heart rate variability (HRV), pre-ejection period (PEP), and heart rate, have been associated with antisocial behaviors including rule-breaking and aggression. Social neuroscience research has begun to investigate how neurobiological underpinnings affect the relationship between social adversity and antisocial/psychopathic behavior in children and adolescents. This study investigated the potential mediating effects of ANS activity on the relationship between social adversity and antisocial behavior in a group of 7- to 10-year-old children from the community (N = 339; 48.2% male). Moderated multiple mediation analyses revealed that low resting heart rate, but not PEP or HRV, mediated the relationship between social adversity and antisocial behavior in males only. Social adversity but not ANS measures were associated with antisocial behavior in females. Findings have implications for understanding the neural influences that underlie antisocial behavior, illustrate the importance of the social environment regarding the expression of these behaviors, and highlight essential gender differences.

Distinct signaling mechanisms in multiple developmental pathways by the SCRAMBLED receptor of Arabidopsis.

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Kwak, Su-Hwan; Woo, Sooah; Lee, Myeong Min; Schiefelbein, John

2014-10-01

SCRAMBLED (SCM), a leucine-rich repeat receptor-like kinase in Arabidopsis (Arabidopsis thaliana), is required for positional signaling in the root epidermis and for tissue/organ development in the shoot. To further understand SCM action, we generated a series of kinase domain variants and analyzed their ability to complement scm mutant defects. We found that the SCM kinase domain, but not kinase activity, is required for its role in root epidermal patterning, supporting the view that SCM is an atypical receptor kinase. We also describe a previously uncharacterized role for SCM in fruit dehiscence, because mature siliques from scm mutants fail to open properly. Interestingly, the kinase domain of SCM appears to be dispensable for this developmental process. Furthermore, we found that most of the SCM kinase domain mutations dramatically inhibit inflorescence development. Because this process is not affected in scm null mutants, it is likely that SCM acts redundantly to regulate inflorescence size. The importance of distinct kinase residues for these three developmental processes provides an explanation for the maintenance of the conserved kinase domain in the SCM protein, and it may generally explain its conservation in other atypical kinases. Furthermore, these results indicate that individual leucine-rich repeat receptor-like kinases may participate in multiple pathways using distinct signaling mechanisms to mediate diverse cellular communication events. © 2014 American Society of Plant Biologists. All Rights Reserved.

A developmental perspective on early-life exposure to neurotoxicants.

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Bellinger, David C; Matthews-Bellinger, Julia A; Kordas, Katarzyna

2016-09-01

Studies of early-life neurotoxicant exposure have not been designed, analyzed, or interpreted in the context of a fully developmental perspective. The goal of this paper is to describe the key principles of a developmental perspective and to use examples from the literature to illustrate the relevance of these principles to early-life neurotoxicant exposures. Four principles are discussed: 1) the effects of early-life neurotoxicant exposure depend on a child's developmental context; 2) deficits caused by early-life exposure initiate developmental cascades that can lead to pathologies that differ from those observed initially; 3) early-life neurotoxicant exposure has intra-familial and intergenerational impacts; 4) the impacts of early-life neurotoxicant exposure influence a child's ability to respond to future insults. The first principle is supported by considerable evidence, but the other three have received much less attention. Incorporating a developmental perspective in studies of early-life neurotoxicant exposures requires prospective collection of data on a larger array of covariates than usually considered, using analytical approaches that acknowledge the transactional processes between a child and the environment and the phenomenon of developmental cascades. Consideration of early-life neurotoxicant exposure within a developmental perspective reveals that many issues remain to be explicated if we are to achieve a deep understanding of the societal health burden associated with early-life neurotoxicant exposures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mixed convection stagnation-point flow of nanofluids over a stretching/shrinking sheet in a porous medium with internal heat generation/absorption

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Dulal Pal

2015-05-01

Full Text Available In this paper, we analyzed the buoyancy-driven radiative non-isothermal heat transfer in a nanofluid stagnation-point flow over a stretching/shrinking sheet embedded in a porous medium.The effects of thermal radiation and internal heat generation/absorption along with suction/injection at the boundary are also considered. Three different types of nanofluids, namely the Copper-water, the Alumina-water and the Titanium dioxide water are considered. The resulting coupled nonlinear differential equations are solved numerically by a fifth-order Runge-Kutta-Fehlberg integration scheme with a shooting technique. A good agreement is found between the present numerical results and the available results in the literature for some special cases. The effects of the physical parameters on the flow and temperature characteristics are presented through tables and graphs, and the salient features are discussed. The results obtained reveal many interesting behaviors that warrant further study on the heat transfer enhancement due to the nanofluids.

Spin Transition in the Lower Mantle: Deep Learning and Pattern Recognition of Superplumes from the Mid-mantle and Mid-mantle Slab Stagnation

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Yuen, D. A.; Shahnas, M. H.; De Hoop, M. V.; Pysklywec, R.

2016-12-01

The broad, slow seismic anomalies under Africa and Pacific cannot be explained without ambiguity. There is no well-established theory to explain the fast structures prevalent globally in seismic tomographic images that are commonly accepted to be the remnants of fossil slabs at different depths in the mantle. The spin transition from high spin to low spin in iron in ferropericlase and perovskite, two major constituents of the lower mantle can significantly impact their physical properties. We employ high resolution 2D-axisymmetric and 3D-spherical control volume models to reconcile the influence of the spin transition-induced anomalies in density, thermal expansivity, and bulk modulus in ferropericlase and perovskite on mantle dynamics. The model results reveal that the spin transition effects increase the mixing in the lower regions of mantle. Depending on the changes of bulk modulus associated with the spin transition, these effects may also cause both stagnation of slabs and rising plumes at mid-mantle depths ( 1600 km). The stagnation may be followed by downward or upward penetration of cold or hot mantle material, respectively, through an avalanche process. The size of these mid-mantle plumes reaches 1500 km across with a radial velocity reaching 20 cm/yr near the seismic transition zone and plume heads exceeding 2500 km across. We will employ a deep-learning algorithm to formulate this challenge as a classification problem where modelling/computation aids in the learning stage for detecting the particular patterns.The parameters based on which the convection models are developed are poorly constrained. There are uncertainties in initial conditions, heterogeneities and boundary conditions in the simulations, which are nonlinear. Thus it is difficult to reconstruct the past configuration over long time scales. In order to extract information and better understand the parameters in mantle convection, we employ deep learning algorithm to search for different

45 CFR 1385.4 - Rights of individuals with developmental disabilities.

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2010-10-01

... university affiliated programs or for projects of national significance grants must also contain an assurance... DISABILITIES, DEVELOPMENTAL DISABILITIES PROGRAM REQUIREMENTS APPLICABLE TO THE DEVELOPMENTAL DISABILITIES PROGRAM § 1385.4 Rights of individuals with developmental disabilities. (a) Section 110 of the Act, Rights...

Identifying support functions in developmental relationships: A self-determination perspective

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Janssen, Suzanne; van Vuuren, Hubrecht A.; de Jong, Menno D.T.

2013-01-01

This study examines the content of developmental networks from the perspective of self-determination theory. We qualitatively examine 18 protégés' constellations of developmental relationships to identify specific types of developmental support functions. Our study shows that the adoption of

Toddler Developmental Delays After Extensive Hospitalization: Primary Care Practitioner Guidelines.

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Lehner, Dana C; Sadler, Lois S

2015-01-01

This review investigated developmental delays toddlers may encounter after a lengthy pediatric hospitalization (30 days or greater). Physical, motor, cognitive, and psychosocial development of children aged 1 to 3 years was reviewed to raise awareness of factors associated with developmental delay after extensive hospitalization. Findings from the literature suggest that neonatal and pediatric intensive care unit (NICU/PICU) graduates are most at risk for developmental delays, but even non-critical hospital stays interrupt development to some extent. Primary care practitioners (PCPs) may be able to minimize risk for delays through the use of formal developmental screening tests and parent report surveys. References and resources are described for developmental assessment to help clinicians recognize delays and to educate families about optimal toddler development interventions. Pediatric PCPs play a leading role in coordinating health and developmental services for the young child following an extensive hospital stay.

Bulimia: A Self-Psychological and Ego-Developmental View.

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Brenner-Liss, Deborah

1986-01-01

Discusses key clinical issues in the treatment of bulimia with clinical examples from a self-psychological and ego-developmental point of view. Identifies three developmental issues for bulimia: self-regulatory, differentiation, and self-esteem. (Author/ABB)

siRNA-Mediated Silencing of doublesex during Female Development of the Dengue Vector Mosquito Aedes aegypti.

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Keshava Mysore

2015-11-01

Full Text Available The development of sex-specific traits, including the female-specific ability to bite humans and vector disease, is critical for vector mosquito reproduction and pathogen transmission. Doublesex (Dsx, a terminal transcription factor in the sex determination pathway, is known to regulate sex-specific gene expression during development of the dengue fever vector mosquito Aedes aegypti. Here, the effects of developmental siRNA-mediated dsx silencing were assessed in adult females. Targeting of dsx during A. aegypti development resulted in decreased female wing size, a correlate for body size, which is typically larger in females. siRNA-mediated targeting of dsx also resulted in decreased length of the adult female proboscis. Although dsx silencing did not impact female membrane blood feeding or mating behavior in the laboratory, decreased fecundity and fertility correlated with decreased ovary length, ovariole length, and ovariole number in dsx knockdown females. Dsx silencing also resulted in disruption of olfactory system development, as evidenced by reduced length of the female antenna and maxillary palp and the sensilla present on these structures, as well as disrupted odorant receptor expression. Female lifespan, a critical component of the ability of A. aegypti to transmit pathogens, was also significantly reduced in adult females following developmental targeting of dsx. The results of this investigation demonstrate that silencing of dsx during A. aegypti development disrupts multiple sex-specific morphological, physiological, and behavioral traits of adult females, a number of which are directly or indirectly linked to mosquito reproduction and pathogen transmission. Moreover, the olfactory phenotypes observed connect Dsx to development of the olfactory system, suggesting that A. aegypti will be an excellent system in which to further assess the developmental genetics of sex-specific chemosensation.

Depolarization-mediated regulation of alternative splicing

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Alok eSharma

2011-12-01

Full Text Available Alternative splicing in eukaryotes plays an important role in regulating gene expression by selectively including alternative exons. A wealth of information has been accumulated that explains how alternative exons are selected in a developmental stage- or tissue-specific fashion. However, our knowledge of how cells respond to environmental changes to alter alternative splicing is very limited. For example, although a number of alternative exons have been shown to be regulated by calcium level alterations, the underlying mechanisms are not well understood. As calcium signaling in neurons plays a crucial role in essential neuronal functions such as learning and memory formation, it is important to understand how this process is regulated at every level in gene expression. The significance of the dynamic control of alternative splicing in response to changes of calcium levels has been largely unappreciated. In this communication, we will summarize the recent advances in calcium signaling-mediated alternative splicing that have provided some insights into the important regulatory mechanisms. In addition to describing the cis-acting RNA elements on the pre-mRNA molecules that respond to changes of intracellular calcium levels, we will summarize how splicing regulators change and affect alternative splicing in this process. We will also discuss a novel mode of calcium-mediated splicing regulation at the level of chromatin structure and transcription.

Developmental disorders: what can be learned from cognitive neuropsychology?

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Castles, Anne; Kohnen, Saskia; Nickels, Lyndsey; Brock, Jon

2014-01-01

The discipline of cognitive neuropsychology has been important for informing theories of cognition and describing the nature of acquired cognitive disorders, but its applicability in a developmental context has been questioned. Here, we revisit this issue, asking whether the cognitive neuropsychological approach can be helpful for exploring the nature and causes of developmental disorders and, if so, how. We outline the key features of the cognitive neuropsychological approach, and then consider how some of the major challenges to this approach from a developmental perspective might be met. In doing so, we distinguish between challenges to the methods of cognitive neuropsychology and those facing its deeper conceptual underpinnings. We conclude that the detailed investigation of patterns of both associations and dissociations, and across both developmental and acquired cases, can assist in describing the cognitive deficits within developmental disorders and in delineating possible causal pathways to their acquisition.

Cyclic electron flow provides acclimatory plasticity for the photosynthetic machinery under various environmental conditions and developmental stages

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Marjaana eSuorsa

2015-09-01

Full Text Available Photosynthetic electron flow operates in two modes, linear and cyclic. In cyclic electron flow (CEF, electrons are recycled around photosystem I. As a result, a transthylakoid proton gradient (ΔpH is generated, leading to the production of ATP without concomitant production of NADPH, thus increasing the ATP/NADPH ratio within the chloroplast. At least two routes for CEF exist: a PGR5-PGRL1–and a chloroplast NDH-like complex mediated pathway. This review focuses on recent findings concerning the characteristics of both CEF routes in higher plants, with special emphasis paid on the crucial role of CEF in under challenging environmental conditions and developmental stages.

Developmental vitamin D deficiency alters MK-801-induced behaviours in adult offspring.

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Kesby, James P; O'Loan, Jonathan C; Alexander, Suzanne; Deng, Chao; Huang, Xu-Feng; McGrath, John J; Eyles, Darryl W; Burne, Thomas H J

2012-04-01

Developmental vitamin D (DVD) deficiency is a candidate risk factor for developing schizophrenia in humans. In rodents DVD deficiency induces subtle changes in the way the brain develops. This early developmental insult leads to select behavioural changes in the adult, such as an enhanced response to amphetamine-induced locomotion in female DVD-deficient rats but not in male DVD-deficient rats and an enhanced locomotor response to the N-methyl-D: -aspartate (NMDA) receptor antagonist, MK-801, in male DVD-deficient rats. However, the response to MK-801-induced locomotion in female DVD-deficient rats is unknown. Therefore, the aim of the current study was to further examine this behavioural finding in male and female rats and assess NMDA receptor density. DVD-deficient Sprague Dawley rats were assessed for locomotion, ataxia, acoustic startle response (ASR) and prepulse inhibition (PPI) of the ASR to multiple doses of MK-801. The NMDA receptor density in relevant brain regions was assessed in a drug-naive cohort. DVD deficiency increased locomotion in response to MK-801 in both sexes. DVD-deficient rats also showed an enhanced ASR compared with control rats, but PPI was normal. Moreover, DVD deficiency decreased NMDA receptor density in the caudate putamen of both sexes. These results suggest that a transient prenatal vitamin D deficiency has a long-lasting effect on NMDA-mediated signalling in the rodent brain and may be a plausible candidate risk factor for schizophrenia and other neuropsychiatric disorders.

Childhood abuse and depression in adulthood: The mediating role of allostatic load.

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Scheuer, Sandra; Wiggert, Nicole; Brückl, Tanja Maria; Awaloff, Yvonne; Uhr, Manfred; Lucae, Susanne; Kloiber, Stefan; Holsboer, Florian; Ising, Marcus; Wilhelm, Frank H

2018-04-22

Traumatic experiences during childhood are considered a major risk factor for depression in adulthood. Childhood trauma may induce physiological dysregulation with long-term effects of increased allostatic load until adulthood, which may lead to depression. Thus, our aim was to investigate whether allostatic load - which represents a multi-system measure of physiological dysregulation - mediates the association between childhood trauma and adult depression. The study sample consisted of 324 depressed inpatients participating in the Munich Antidepressant Response Signature (MARS) project and 261 mentally healthy control participants. The mediation analysis using a case-control approach included childhood trauma, i.e., physical and sexual abuse, as predictor variables and an allostatic load index comprised of 12 stress-related biomarkers as mediator. Age and sex were included as covariates. Mediation analyses revealed that the influence of physical abuse, but not sexual abuse, during childhood on depression in adulthood was mediated by allostatic load. This effect was moderated by age: particularly young (18-42 years) and middle-aged (43-54 years) adults with a history of physical abuse during childhood exhibited high allostatic load, which in turn was associated with increased rates of depression, but this was not the case for older participants (55-81 years). Results support the theoretical assumption of allostatic load mediating the effect of physical abuse during childhood on depression in adulthood. This predominantly holds for younger participants, while depression in older participants was independent of physical abuse and allostatic load. The effect of sexual abuse on depression, however, was not mediated by allostatic load. Identifying allostatic load biomarkers prospectively in the developmental course of depression is an important target for future research. Copyright © 2018 Elsevier Ltd. All rights reserved.

Normal composite face effects in developmental prosopagnosia.

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Biotti, Federica; Wu, Esther; Yang, Hua; Jiahui, Guo; Duchaine, Bradley; Cook, Richard

2017-10-01

Upright face perception is thought to involve holistic processing, whereby local features are integrated into a unified whole. Consistent with this view, the top half of one face appears to fuse perceptually with the bottom half of another, when aligned spatially and presented upright. This 'composite face effect' reveals a tendency to integrate information from disparate regions when faces are presented canonically. In recent years, the relationship between susceptibility to the composite effect and face recognition ability has received extensive attention both in participants with normal face recognition and participants with developmental prosopagnosia. Previous results suggest that individuals with developmental prosopagnosia may show reduced susceptibility to the effect suggestive of diminished holistic face processing. Here we describe two studies that examine whether developmental prosopagnosia is associated with reduced composite face effects. Despite using independent samples of developmental prosopagnosics and different composite procedures, we find no evidence for reduced composite face effects. The experiments yielded similar results; highly significant composite effects in both prosopagnosic groups that were similar in magnitude to the effects found in participants with normal face processing. The composite face effects exhibited by both samples and the controls were greatly diminished when stimulus arrangements were inverted. Our finding that the whole-face binding process indexed by the composite effect is intact in developmental prosopagnosia indicates that other factors are responsible for developmental prosopagnosia. These results are also inconsistent with suggestions that susceptibility to the composite face effect and face recognition ability are tightly linked. While the holistic process revealed by the composite face effect may be necessary for typical face perception, it is not sufficient; individual differences in face recognition ability

Developmental programming and transgenerational transmission of obesity.

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Vickers, M H

2014-01-01

The global obesity pandemic is often causally linked to marked changes in diet and lifestyle, namely marked increases in dietary intakes of high-energy diets and concomitant reductions in physical activity levels. However, far less attention has been paid to the role of developmental plasticity and alterations in phenotypic outcomes resulting from environmental perturbations during the early-life period. Human and animal studies have highlighted the link between alterations in the early-life environment and increased susceptibility to obesity and related metabolic disorders in later life. In particular, altered maternal nutrition, including both undernutrition and maternal obesity, has been shown to lead to transgenerational transmission of metabolic disorders. This association has been conceptualised as the developmental programming hypothesis whereby the impact of environmental influences during critical periods of developmental plasticity can elicit lifelong effects on the physiology of the offspring. Further, evidence to date suggests that this developmental programming is a transgenerational phenomenon, with a number of studies showing transmission of programming effects to subsequent generations, even in the absence of continued environmental stressors, thus perpetuating a cycle of obesity and metabolic disorders. The mechanisms responsible for these transgenerational effects remain poorly understood; evidence to date suggests a number of potential mechanisms underpinning the transgenerational transmission of the developmentally programmed phenotype through both the maternal and paternal lineage. Transgenerational phenotype transmission is often seen as a form of epigenetic inheritance with evidence showing both germline and somatic inheritance of epigenetic modifications leading to phenotype changes across generations. However, there is also evidence for non-genomic components as well as an interaction between the developing fetus with the in utero

Autism in community pre-schoolers: developmental profiles.

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Kantzer, Anne-Katrin; Fernell, Elisabeth; Gillberg, Christopher; Miniscalco, Carmela

2013-09-01

Autism is often a complex developmental disorder. The aim of the present study was to describe the developmental characteristics of 129 1-4-year-old children (102 boys, 27 girls) referred for clinical assessment (mean age 2.9 years) due to suspicion of autism spectrum disorder (ASD) after community screening at Child Health Care centers. All children were clinically assessed at the Child Neuropsychiatry Clinic (CNC) in Gothenburg by a research team (neurodevelopmental examination, structured interviews and general cognitive and language examinations). Of the 129 children, 100 met diagnostic criteria for ASD (69 with autistic disorder, and 31 with atypical autism/pervasive developmental disorder-not otherwise specified). The remaining 29 children had a variety of developmental disorders, most often attention-deficit/hyperactivity disorder (ADHD), language disorder, borderline intellectual functioning, and intellectual developmental disorder (IDD) with (n=25) or without (n=4) autistic traits (AT). IDD was found in 36% of the 100 children with ASD, and in 4% of the 25 children with AT. Of the children with ASD, 56% had language disorder with no or just a few words at the initial assessment at the CNC, many of whom in combination with IDD. Hyperactivity was found in 37% of those with ASD and in 40% of those with AT. Epilepsy was found in 6% of the total group and in 7% of those with a diagnosis of ASD. Of the latter group 11% had a history of regression, while none of the AT cases had a similar background. When results were compared with a non-screened preschool ASD group of 208 children, referred for ASD intervention at a mean age of 3.4 years, very similar developmental profiles were seen. In conclusion, early community ASD screening appears to systematically identify those children who are in need of intervention and follow-up. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessing hopping developmental level in childhood using wearable inertial sensor devices.

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Masci, Ilaria; Vannozzi, Giuseppe; Getchell, Nancy; Cappozzo, Aurelio

2012-07-01

Assessing movement skills is a fundamental issue in motor development. Current process-oriented assessments, such as developmental sequences, are based on subjective judgments; if paired with quantitative assessments, a better understanding of movement performance and developmental change could be obtained. Our purpose was to examine the use of inertial sensors to evaluate developmental differences in hopping over distance. Forty children executed the task wearing the inertial sensor and relevant time durations and 3D accelerations were obtained. Subjects were also categorized in different developmental levels according to the hopping developmental sequence. Results indicated that some time and kinematic parameters changed with some developmental levels, possibly as a function of anthropometry and previous motor experience. We concluded that, since inertial sensors were suitable in describing hopping performance and sensitive to developmental changes, this technology is promising as an in-field and user-independent motor development assessment tool.

Emotional insecurity about the community: A dynamic, within-person mediator of child adjustment in contexts of political violence.

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Cummings, E Mark; Merrilees, Christine; Taylor, Laura K; Goeke-Morey, Marcie; Shirlow, Peter

2017-02-01

Over 1 billion children worldwide are exposed to political violence and armed conflict. The current conclusions are qualified by limited longitudinal research testing sophisticated process-oriented explanatory models for child adjustment outcomes. In this study, consistent with a developmental psychopathology perspective emphasizing the value of process-oriented longitudinal study of child adjustment in developmental and social-ecological contexts, we tested emotional insecurity about the community as a dynamic, within-person mediating process for relations between sectarian community violence and child adjustment. Specifically, this study explored children's emotional insecurity at a person-oriented level of analysis assessed over 5 consecutive years, with child gender examined as a moderator of indirect effects between sectarian community violence and child adjustment. In the context of a five-wave longitudinal research design, participants included 928 mother-child dyads in Belfast (453 boys, 475 girls) drawn from socially deprived, ethnically homogenous areas that had experienced political violence. Youth ranged in age from 10 to 20 years and were 13.24 (SD = 1.83) years old on average at the initial time point. Greater insecurity about the community measured over multiple time points mediated relations between sectarian community violence and youth's total adjustment problems. The pathway from sectarian community violence to emotional insecurity about the community was moderated by child gender, with relations to emotional insecurity about the community stronger for girls than for boys. The results suggest that ameliorating children's insecurity about community in contexts of political violence is an important goal toward improving adolescents' well-being and adjustment. These results are discussed in terms of their translational research implications, consistent with a developmental psychopathology model for the interface between basic and intervention

Spelling performance of students with developmental dyslexia and with developmental dyslexia associated to attention deficit disorder and hyperactivity.

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Alves, Débora Cristina; Casella, Erasmo Barbante; Ferraro, Alexandre Arcanjo

2016-04-01

Purpose to analyze and classify the spelling performance according to the semiology of spelling error of children with developmental dyslexia (DD) and with developmental dyslexia associated to attention deficit disorder and hyperactivity(DD and ADHD) comparing them to a group of children without learning process complaints. Methods Seventy students, from the third to fifth grade, participated in this study divided as follows: 32 children without complaints of learning difficulties (GI), mean age 9.5 years; 22 students with developmental dyslexia (GII), mean age 10 years; 16 scholars with developmental dyslexia associated to attention deficit disorders and hyperactivity (GIII), mean age 9.9. Spelling skills were assessed through a standardized word dictation task. Results Data indicated that GII and GIII children presented lower performance when compared with typically developed children. There was no statistical difference between the performance of GII and GIII children regarding the score reached in spelling, although GIII children presented the lowest performance. We observed differences between GII and GIII only in the type of misspelling. Conclusion Data from this research contribute to develop better programs for intervention in the studied population.

DMPD: Developmental plasticity of lymphocytes. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18472258 Developmental plasticity of lymphocytes. Cobaleda C, Busslinger M. Curr Op...in Immunol. 2008 Apr;20(2):139-48. Epub 2008 May 9. (.png) (.svg) (.html) (.csml) Show Developmental plastic...ity of lymphocytes. PubmedID 18472258 Title Developmental plasticity of lymphocytes. Authors Cobaleda C, Bus

VIII. THE PAST, PRESENT, AND FUTURE OF DEVELOPMENTAL METHODOLOGY.

Science.gov (United States)

Little, Todd D; Wang, Eugene W; Gorrall, Britt K

2017-06-01

This chapter selectively reviews the evolution of quantitative practices in the field of developmental methodology. The chapter begins with an overview of the past in developmental methodology, discussing the implementation and dissemination of latent variable modeling and, in particular, longitudinal structural equation modeling. It then turns to the present state of developmental methodology, highlighting current methodological advances in the field. Additionally, this section summarizes ample quantitative resources, ranging from key quantitative methods journal articles to the various quantitative methods training programs and institutes. The chapter concludes with the future of developmental methodology and puts forth seven future innovations in the field. The innovations discussed span the topics of measurement, modeling, temporal design, and planned missing data designs. Lastly, the chapter closes with a brief overview of advanced modeling techniques such as continuous time models, state space models, and the application of Bayesian estimation in the field of developmental methodology. © 2017 The Society for Research in Child Development, Inc.

Perceptual skills of children with developmental coordination disorder

NARCIS (Netherlands)

Schoemaker, M.M.; van der Wees, M.; Flapper, B.; Verheij-Jansen, N.; Scholten-Jaegers, S.; Geuze, R.H.

The aim of this study was to investigate whether children with a Developmental Coordination Disorder (DCD) experience problems in the processing of visual, proprioceptive or tactile information. Different aspects of visual perception were tested with the Developmental Test of Visual Perception

Continuing harmonization of terminology and innovations for methodologies in developmental toxicology: Report of the 8th Berlin Workshop on Developmental Toxicity, 14-16 May 2014.

Science.gov (United States)

Solecki, Roland; Rauch, Martina; Gall, Andrea; Buschmann, Jochen; Clark, Ruth; Fuchs, Antje; Kan, Haidong; Heinrich, Verena; Kellner, Rupert; Knudsen, Thomas B; Li, Weihua; Makris, Susan L; Ooshima, Yojiro; Paumgartten, Francisco; Piersma, Aldert H; Schönfelder, Gilbert; Oelgeschläger, Michael; Schaefer, Christof; Shiota, Kohei; Ulbrich, Beate; Ding, Xuncheng; Chahoud, Ibrahim

2015-11-01

This article is a report of the 8th Berlin Workshop on Developmental Toxicity held in May 2014. The main aim of the workshop was the continuing harmonization of terminology and innovations for methodologies used in the assessment of embryo- and fetotoxic findings. The following main topics were discussed: harmonized categorization of external, skeletal, visceral and materno-fetal findings into malformations, variations and grey zone anomalies, aspects of developmental anomalies in humans and laboratory animals, and innovations for new methodologies in developmental toxicology. The application of Version 2 terminology in the DevTox database was considered as a useful improvement in the categorization of developmental anomalies. Participants concluded that initiation of a project for comparative assessments of developmental anomalies in humans and laboratory animals could support regulatory risk assessment and university-based training. Improvement of new methodological approaches for alternatives to animal testing should be triggered for a better understanding of developmental outcomes. Copyright © 2015. Published by Elsevier Inc.

Examining the Criterion-Related Validity of the Pervasive Developmental Disorder Behavior Inventory

Science.gov (United States)

McMorris, Carly A.; Perry, Adrienne

2015-01-01

The Pervasive Developmental Disorder Behavior Inventory is a questionnaire designed to aid in the diagnosis of pervasive developmental disorders or autism spectrum disorders. The Pervasive Developmental Disorder Behavior Inventory assesses adaptive and maladaptive behaviors associated with pervasive developmental disorders and provides an…

Integrating 4-d light-sheet imaging with interactive virtual reality to recapitulate developmental cardiac mechanics and physiology

Science.gov (United States)

Ding, Yichen; Yu, Jing; Abiri, Arash; Abiri, Parinaz; Lee, Juhyun; Chang, Chih-Chiang; Baek, Kyung In; Sevag Packard, René R.; Hsiai, Tzung K.

2018-02-01

There currently is a limited ability to interactively study developmental cardiac mechanics and physiology. We therefore combined light-sheet fluorescence microscopy (LSFM) with virtual reality (VR) to provide a hybrid platform for 3- dimensional (3-D) architecture and time-dependent cardiac contractile function characterization. By taking advantage of the rapid acquisition, high axial resolution, low phototoxicity, and high fidelity in 3-D and 4-D (3-D spatial + 1-D time or spectra), this VR-LSFM hybrid methodology enables interactive visualization and quantification otherwise not available by conventional methods such as routine optical microscopes. We hereby demonstrate multi-scale applicability of VR-LSFM to 1) interrogate skin fibroblasts interacting with a hyaluronic acid-based hydrogel, 2) navigate through the endocardial trabecular network during zebrafish development, and 3) localize gene therapy-mediated potassium channel expression in adult murine hearts. We further combined our batch intensity normalized segmentation (BINS) algorithm with deformable image registration (DIR) to interface a VR environment for the analysis of cardiac contraction. Thus, the VR-LSFM hybrid platform demonstrates an efficient and robust framework for creating a user-directed microenvironment in which we uncovered developmental cardiac mechanics and physiology with high spatiotemporal resolution.

How teacher emotional support motivates students: The mediating roles of perceived peer relatedness, autonomy support, and competence

Science.gov (United States)

Ruzek, Erik A.; Hafen, Christopher A.; Allen, Joseph P.; Gregory, Anne; Mikami, Amori Yee; Pianta, Robert C.

2017-01-01

Multilevel mediation analyses test whether students' mid-year reports of classroom experiences of autonomy, relatedness with peers, and competence mediate associations between early in the school year emotionally-supportive teacher-student interactions (independently observed) and student-reported academic year changes in mastery motivation and behavioral engagement. When teachers were observed to be more emotionally-supportive in the beginning of the school year, adolescents reported academic year increases in their behavioral engagement and mastery motivation. Mid-year student reports indicated that in emotionally-supportive classrooms, adolescents experienced more developmentally-appropriate opportunities to exercise autonomy in their day-to-day activities and had more positive relationships with their peers. Analyses of the indirect effects of teacher emotional support on students' engagement and motivation indicated significant mediating effects of autonomy and peer relatedness experiences, but not competence beliefs, in this sample of 960 students (ages 11–17) in the classrooms of 68 middle and high school teachers in 12 U.S. schools. PMID:28190936

How teacher emotional support motivates students: The mediating roles of perceived peer relatedness, autonomy support, and competence.

Science.gov (United States)

Ruzek, Erik A; Hafen, Christopher A; Allen, Joseph P; Gregory, Anne; Mikami, Amori Yee; Pianta, Robert C

2016-04-01

Multilevel mediation analyses test whether students' mid-year reports of classroom experiences of autonomy, relatedness with peers, and competence mediate associations between early in the school year emotionally-supportive teacher-student interactions (independently observed) and student-reported academic year changes in mastery motivation and behavioral engagement. When teachers were observed to be more emotionally-supportive in the beginning of the school year, adolescents reported academic year increases in their behavioral engagement and mastery motivation. Mid-year student reports indicated that in emotionally-supportive classrooms, adolescents experienced more developmentally-appropriate opportunities to exercise autonomy in their day-to-day activities and had more positive relationships with their peers. Analyses of the indirect effects of teacher emotional support on students' engagement and motivation indicated significant mediating effects of autonomy and peer relatedness experiences, but not competence beliefs, in this sample of 960 students (ages 11-17) in the classrooms of 68 middle and high school teachers in 12 U.S. schools.

Developmental Methodology as a Context for Interdisciplinary Dialogue in Developmental Science

Science.gov (United States)

Card, Noel A.

2014-01-01

In this comment, I first highlight the contributions of Robinson-Cimpian, Lubienski, Ganley, and Copur-Gencturk (2014) in particular and a more interdisciplinary approach in general for the subdiscipline of developmental psychology. Second, I identify some historic methodological foci of psychology and encourage Robinson-Cimpian et al. to consider…

48 CFR 1019.202-70-13 - Developmental assistance.

Science.gov (United States)

2010-10-01

... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 1019.202-70-13 Developmental assistance. The forms of developmental assistance a mentor can provide to a protégé include: (a) Management guidance relating to financial management, organizational management, overall business management/planning, business development...

Clinical profile of children with developmental delay and microcephaly

Science.gov (United States)

Aggarwal, Anju; Mittal, Hema; Patil, Rahul; Debnath, Sanjib; Rai, Anuradha

2013-01-01

Aim: To study the profile of children with developmental delay and microcephaly. Materials and Methods: Children attending child development clinic with developmental delay were evaluated as per protocol. Z scores of head circumference were calculated using WHO charts. Clinical, radiological and etiological profile of those with microcephaly and those without was compared. Results: Of the 414 children with developmental delay 231 had microcephaly (z score ≤ -3). Mean age of children with microcephaly was 35.1 ± 27.9 months (range 4-184), males (72.7%). Comorbidities were epilepsy (42.9%), visual abnormality (26.4%), hearing abnormality (16.9%). Mean DQ was 29.75 + 17.8 in those with microcephaly was significantly lower compared to the rest (P = 0.002). Secondary microcephaly was associated with cerebral palsy in 69.7%. Other causes were congenital infections (4), inborn error of metabolism (3), post-meningoencephalitis (5), malformations (12), and syndromic (13). Neuroimaging was done in 118 (51.1%) cases of which 104 (88.1%) were abnormal. On comparison children with microcephaly had more epilepsy, lower developmental quotient, vision abnormalities findings as compared to normocephalic children with developmental delay (P > 0.05). Conclusion: Microcephaly was associated with lower, DQ, higher comorbidities in children with developmental delay. Spastic CP is commonly associated with microcephaly. PMID:24250161

Facts about Developmental Disabilities

Science.gov (United States)

... play, learn, speak, behave, and move (for example, crawling and walking). Children develop at their own pace, ... person’s lifetime. Most developmental disabilities begin before a baby is born, but some can happen after birth ...

Past climate change on Sky Islands drives novelty in a core developmental gene network and its phenotype.

Science.gov (United States)

Favé, Marie-Julie; Johnson, Robert A; Cover, Stefan; Handschuh, Stephan; Metscher, Brian D; Müller, Gerd B; Gopalan, Shyamalika; Abouheif, Ehab

2015-09-04

findings reveal dynamics of developmental gene network evolution in wild populations. This holds important implications: (1) for understanding how phenotypic novelty is generated in the wild; (2) for providing a possible bridge between micro- and macroevolution; and (3) for understanding how development mediates the response of organisms to past, and potentially, future climate change.

Developmental Programming of Adult Disease: Reprogramming by Melatonin?

Directory of Open Access Journals (Sweden)

You-Lin Tain

2017-02-01

Full Text Available Adult-onset chronic non-communicable diseases (NCDs can originate from early life through so-called the “developmental origins of health and disease” (DOHaD or “developmental programming”. The DOHaD concept offers the “reprogramming” strategy to shift the treatment from adulthood to early life, before clinical disease is apparent. Melatonin, an endogenous indoleamine produced by the pineal gland, has pleiotropic bioactivities those are beneficial in a variety of human diseases. Emerging evidence support that melatonin is closely inter-related to other proposed mechanisms contributing to the developmental programming of a variety of chronic NCDs. Recent animal studies have begun to unravel the multifunctional roles of melatonin in many experimental models of developmental programming. Even though some progress has been made in research on melatonin as a reprogramming strategy to prevent DOHaD-related NCDs, future human studies should aim at filling the translational gap between animal models and clinical trials. Here, we review several key themes on the reprogramming effects of melatonin in DOHaD research. We have particularly focused on the following areas: mechanisms of developmental programming; the interrelationship between melatonin and mechanisms underlying developmental programming; pathophysiological roles of melatonin in pregnancy and fetal development; and insight provided by animal models to support melatonin as a reprogramming therapy. Rates of NCDs are increasing faster than anticipated all over the world. Hence, there is an urgent need to understand reprogramming mechanisms of melatonin and to translate experimental research into clinical practice for halting a growing list of DOHaD-related NCDs.

Developmental Programming of Adult Disease: Reprogramming by Melatonin?

Science.gov (United States)

Tain, You-Lin; Huang, Li-Tung; Hsu, Chien-Ning

2017-02-16

Adult-onset chronic non-communicable diseases (NCDs) can originate from early life through so-called the "developmental origins of health and disease" (DOHaD) or "developmental programming". The DOHaD concept offers the "reprogramming" strategy to shift the treatment from adulthood to early life, before clinical disease is apparent. Melatonin, an endogenous indoleamine produced by the pineal gland, has pleiotropic bioactivities those are beneficial in a variety of human diseases. Emerging evidence support that melatonin is closely inter-related to other proposed mechanisms contributing to the developmental programming of a variety of chronic NCDs. Recent animal studies have begun to unravel the multifunctional roles of melatonin in many experimental models of developmental programming. Even though some progress has been made in research on melatonin as a reprogramming strategy to prevent DOHaD-related NCDs, future human studies should aim at filling the translational gap between animal models and clinical trials. Here, we review several key themes on the reprogramming effects of melatonin in DOHaD research. We have particularly focused on the following areas: mechanisms of developmental programming; the interrelationship between melatonin and mechanisms underlying developmental programming; pathophysiological roles of melatonin in pregnancy and fetal development; and insight provided by animal models to support melatonin as a reprogramming therapy. Rates of NCDs are increasing faster than anticipated all over the world. Hence, there is an urgent need to understand reprogramming mechanisms of melatonin and to translate experimental research into clinical practice for halting a growing list of DOHaD-related NCDs.

Intracranial developmental venous anomaly: is it asymptomatic?

Science.gov (United States)

Puente, A Bolívar; de Asís Bravo Rodríguez, F; Bravo Rey, I; Romero, E Roldán

2018-03-16

Intracranial developmental venous anomalies are the most common vascular malformation. In the immense majority of cases, these anomalies are asymptomatic and discovered incidentally, and they are considered benign. Very exceptionally, however, they can cause neurological symptoms. In this article, we present three cases of patients with developmental venous anomalies that presented with different symptoms owing to complications derived from altered venous drainage. These anomalies were located in the left insula, right temporal lobe, and cerebellum. The exceptionality of the cases presented as well as of the images associated, which show the mechanism through which the symptoms developed, lies in the low incidence of symptomatic developmental venous anomalies reported in the literature. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

THE MAKING OF FAMILY VALUES: DEVELOPMENTAL IDEALISM IN GANSU, CHINA

Science.gov (United States)

Lai, Qing; Thornton, Arland

2014-01-01

This paper examines the role of developmental thinking in the making of family values. We analyze survey data collected from Gansu Province in China with regular and multilevel logit models. The results show that individuals’ endorsement of neolocal residence, self-choice marriage, gender egalitarianism, late marriage for women, and low fertility depends on the conjunction of preference for development and beliefs in its association with those family attributes, which we term developmental idealism associational evaluation. Furthermore, such impact of developmental thinking on family values holds robust in the presence of indigenous ideational forces, in this case Islamic religion. Although Islam influences family values in the opposite direction than developmental ideas do, the effect of Developmental Idealism associational evaluation does not differ significantly between Muslims and non-Muslims. PMID:25769860

Selecting score types for longitudinal evaluations: the responsiveness of the Comprehensive Developmental Inventory for Infants and Toddlers in children with developmental disabilities

Directory of Open Access Journals (Sweden)

Tsai YP

2016-05-01

Full Text Available Yu-Pei Tsai,1,2 Li-Chen Tung,1,3 Ya-Chen Lee,4 Yu-Lin Wang,1,5 Yun-Shan Yen,1 Kuan-Lin Chen4,6 1Department of Physical Medicine and Rehabilitation, Chi-Mei Medical Center, Tainan, 2Department of Special Education, National Chiayi University, Chiayi, 3School of Medicine, Chung Shan Medical University, Taichung, 4Department of Occupational Therapy, College of Medicine, National Cheng Kung University, 5Department of Sports Management, Chia Nan University of Pharmacy and Science, 6Department of Physical Medicine and Rehabilitation, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan Objective: The objective of this study was to examine the responsiveness of the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT in children with developmental disabilities (DD.Methods: The responsiveness of a measure is its ability to detect change over time, and it is fundamental to an outcome measure for detecting changes over time. We compared the responsiveness of four types of scores (ie, raw scores, developmental ages [DAs], percentile ranks [PRs], and developmental quotients [DQs] in the five subtests of the CDIIT. The CDIIT was administrated three times at intervals of 3 months on 32 children with DD aged between 5 months and 64 months (mean =30.6, standard deviation [SD] =17.8. The CDIIT is a pediatric norm-referenced assessment commonly used for clinical diagnosis of developmental delays in five developmental areas: cognition, language, motor, social, and self-care skills. The responsiveness was analyzed using three methods: effect size, standardized response mean, and paired t-test.Results: The effect size results showed that at the 3-month and 6-month follow-ups, responsiveness was small or moderate in the raw scores and DAs of most of the subtest scores of the CDIIT, but the level of responsiveness varied in the PRs and DQs. The standardized response mean results of the 3-month

Fired up or burned out? How developmental challenge differentially impacts leader behavior.

Science.gov (United States)

Courtright, Stephen H; Colbert, Amy E; Choi, Daejeong

2014-07-01

Leadership development research has largely drawn on experiential and enactive learning theories to explore the positive effects of developmental challenge on leaders. In contrast, we examined potential positive and negative effects of developmental challenge (i.e., challenging job assignments) on leader behavior through an alternative theoretical lens--transactional stress theory. We predicted, on one hand, that developmental challenge may be associated with higher leader engagement and transformational leadership behavior; however, developmental challenge also has the potential to be associated with higher leader emotional exhaustion and laissez-faire leadership behavior. We further proposed that leadership self-efficacy (LSE) moderates these potential effects of developmental challenge and helps explain why leaders react either positively or negatively to developmental challenge. We tested our hypotheses in a sample of 153 leaders and 631 direct reports at a Fortune 500 company. Findings supported positive relationships among developmental challenge, leader engagement, and transformational leadership. However, we also found support for significant relationships among developmental challenge, emotional exhaustion, and laissez-faire leadership. Additionally, leaders lower in LSE were more likely to encounter the negative effects of developmental challenge by experiencing increased emotional exhaustion and displaying laissez-faire leadership behaviors. Our study contributes to theory and practice by elucidating a "dark side" of developmental challenge, identifying LSE as a moderator of the negative effects of developmental challenge, identifying antecedents of transformational and laissez-faire leadership behaviors, and investigating demands and stress in leadership roles.

Acetaminophen developmental pharmacokinetics in premature neonates and infants

DEFF Research Database (Denmark)

Anderson, Brian J; van Lingen, Richard A; Hansen, Tom G

2002-01-01

The aim of this study was to describe acetaminophen developmental pharmacokinetics in premature neonates through infancy to suggest age-appropriate dosing regimens.......The aim of this study was to describe acetaminophen developmental pharmacokinetics in premature neonates through infancy to suggest age-appropriate dosing regimens....

Developmental psychopathology in an era of molecular genetics and neuroimaging: A developmental neurogenetics approach.

Science.gov (United States)

Hyde, Luke W

2015-05-01

The emerging field of neurogenetics seeks to model the complex pathways from gene to brain to behavior. This field has focused on imaging genetics techniques that examine how variability in common genetic polymorphisms predict differences in brain structure and function. These studies are informed by other complimentary techniques (e.g., animal models and multimodal imaging) and have recently begun to incorporate the environment through examination of Imaging Gene × Environment interactions. Though neurogenetics has the potential to inform our understanding of the development of psychopathology, there has been little integration between principles of neurogenetics and developmental psychopathology. The paper describes a neurogenetics and Imaging Gene × Environment approach and how these approaches have been usefully applied to the study of psychopathology. Six tenets of developmental psychopathology (the structure of phenotypes, the importance of exploring mechanisms, the conditional nature of risk, the complexity of multilevel pathways, the role of development, and the importance of who is studied) are identified, and how these principles can further neurogenetics applications to understanding the development of psychopathology is discussed. A major issue of this piece is how neurogenetics and current imaging and molecular genetics approaches can be incorporated into developmental psychopathology perspectives with a goal of providing models for better understanding pathways from among genes, environments, the brain, and behavior.

Developmental Screening Disparities for Languages Other than English and Spanish.

Science.gov (United States)

Knuti Rodrigues, Kristine; Hambidge, Simon J; Dickinson, Miriam; Richardson, Douglas B; Davidson, Arthur J

2016-01-01

Limited English proficiency (LEP) is a known barrier to preventive care. Children from families with LEP face socioeconomic circumstances associated with increased odds of developmental delays and decreased participation in early care and education programs. Little is known about developmental surveillance and screening for children from families who speak languages other than English and Spanish. We sought to compare developmental surveillance and screening at well-child visits (WCVs) by preferred parental language. Using a retrospective cohort (n = 15,320) of children aged 8 to 40 months with ≥2 WCVs from January 1, 2006, to July 1, 2010, in a community health system, 450 children from 3 language groups (150 English, 150 Spanish, and 150 non-English, non-Spanish) were randomly selected. Chart review assessed 2 primary outcomes, developmental surveillance at 100% of WCVs and screened with a standardized developmental screening tool, and also determined whether children were referred for diagnostic developmental evaluation. Bivariate and multiple logistic regression analyses were conducted. Compared to the English-speaking group, the non-English, non-Spanish group had lower odds of receiving developmental surveillance at 100% of WCVs (odds ratio, 0.3; 95% confidence interval, 0.2, 0.5) and of being screened with a standardized developmental screening tool (odds ratio, 0.1; 95% confidence interval, 0.1, 0.2). There were no differences between the English- and Spanish-speaking groups. Though underpowered, no differences were found for referral. Improved developmental surveillance and screening are needed for children from families who speak languages other than English and Spanish. Lack of statistically significant differences between English- and Spanish-speaking groups suggests that improved translation and interpretation resources may decrease disparities. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

AMPA receptor mediated excitotoxicity in neocortical neurons is developmentally regulated and dependent upon receptor desensitization

DEFF Research Database (Denmark)

Jensen, J B; Schousboe, A; Pickering, D S

1998-01-01

with a fast and rapidly desensitizing response, this could explain the relatively low toxicity produced by 500 microM AMPA. This was investigated by blocking AMPA receptor desensitization with cyclothiazide. Using a lower concentration (25 microM) of AMPA, addition of 50 microM cyclothiazide increased...... the AMPA induced excitotoxicity in cultured cortical neurons at all DIV except for DIV 2. This combination of AMPA + cyclothiazide yielded 77% cell death for DIV 12 cultures. In contrast to the results observed with 500 microM AMPA, the neurotoxicity mediated directly by AMPA receptors when desensitization...

Nanoparticle-induced neuronal toxicity across placental barriers is mediated by autophagy and dependent on astrocytes

Science.gov (United States)

Hawkins, Simon J.; Crompton, Lucy A.; Sood, Aman; Saunders, Margaret; Boyle, Noreen T.; Buckley, Amy; Minogue, Aedín M.; McComish, Sarah F.; Jiménez-Moreno, Natalia; Cordero-Llana, Oscar; Stathakos, Petros; Gilmore, Catherine E.; Kelly, Stephen; Lane, Jon D.; Case, C. Patrick; Caldwell, Maeve A.

2018-05-01

The potential for maternal nanoparticle (NP) exposures to cause developmental toxicity in the fetus without the direct passage of NPs has previously been shown, but the mechanism remained elusive. We now demonstrate that exposure of cobalt and chromium NPs to BeWo cell barriers, an in vitro model of the human placenta, triggers impairment of the autophagic flux and release of interleukin-6. This contributes to the altered differentiation of human neural progenitor cells and DNA damage in the derived neurons and astrocytes. Crucially, neuronal DNA damage is mediated by astrocytes. Inhibiting the autophagic degradation in the BeWo barrier by overexpression of the dominant-negative human ATG4BC74A significantly reduces the levels of DNA damage in astrocytes. In vivo, indirect NP toxicity in mice results in neurodevelopmental abnormalities with reactive astrogliosis and increased DNA damage in the fetal hippocampus. Our results demonstrate the potential importance of autophagy to elicit NP toxicity and the risk of indirect developmental neurotoxicity after maternal NP exposure.

Computer-based multisensory learning in children with developmental dyslexia.

Science.gov (United States)

Kast, Monika; Meyer, Martin; Vögeli, Christian; Gross, Markus; Jäncke, Lutz

2007-01-01

Several attempts have been made to remediate developmental dyslexia using various training environments. Based on the well-known retrieval structure model, the memory strength of phonemes and graphemes should be strengthened by visual and auditory associations between graphemes and phonemes. Using specifically designed training software, we examined whether establishing a multitude of visuo-auditory associations might help to mitigate writing errors in children with developmental dyslexia. Forty-three children with developmental dyslexia and 37 carefully matched normal reading children performed a computer-based writing training (15-20 minutes 4 days a week) for three months with the aim to recode a sequential textual input string into a multi-sensory representation comprising visual and auditory codes (including musical tones). The study included four matched groups: a group of children with developmental dyslexia (n=20) and a control group (n=18) practiced with the training software in the first period (3 months, 15-20 minutes 4 days a week), while a second group of children with developmental dyslexia (n=23) (waiting group) and a second control group (n=19) received no training during the first period. In the second period the children with developmental dyslexia and controls who did not receive training during the first period now took part in the training. Children with developmental dyslexia who did not perform computer-based training during the first period hardly improved their writing skills (post-pre improvement of 0-9%), the dyslexic children receiving training strongly improved their writing skills (post-pre improvement of 19-35%). The group who did the training during the second period also revealed improvement of writing skills (post-pre improvement of 27-35%). Interestingly, we noticed a strong transfer from trained to non-trained words in that the children who underwent the training were also better able to write words correctly that were not part

Boundary layer flow of an oldroyd-b fluid in the region of stagnation point over a stretching sheet

International Nuclear Information System (INIS)

Sajid, M.

2012-01-01

The mathematical modeling for the two-dimensional boundary layer flow of an Oldroyd-B fluid is presented. The developed equations are used to discuss the problem of two-dimensional flow in the region of a stagnation point over a stretching sheet. The obtained partial differential equations are reduced to an ordinary differential equation by a suitable transformation. The obtained equation is then solved using a finite difference method. The influence of the pertinent fluid parameters on the velocity is discussed through graphs. The behavior of f (0) is also investigated for the change in parameter values. Our main focus is to discuss the effects of relaxation and retardation time parameters on the velocity components in the x and y directions. In addition to it the skin friction coefficient is evaluated which is a measure of frictional drag at the surface illustrates that the boundary layer thickness decreases due to an increase in the relaxation time constant. The reason is that a higher relaxation time constant give rise to a slower recovery process and as a result the boundary layer thickness grows at a slower rate for a higher value of the relaxation time constant when compared with its lower value. (orig./A.B.)

Assessment of the Developmental Toxicity of Epidermal Growth ...

African Journals Online (AJOL)

Purpose: To determine whether epidermal growth factor (EGF) is involved in reproductive developmental toxicity, using the embryonic stem cell test (EST), as well as ascertain how EGF influences embryonic development. Methods: To predict developmental toxicity on the basis of reducing cell viability and inhibition of ...

Neighborhoods, Schools, and Academic Achievement: A Formal Mediation Analysis of Contextual Effects on Reading and Mathematics Abilities.

Science.gov (United States)

Wodtke, Geoffrey T; Parbst, Matthew

2017-10-01

Although evidence indicates that neighborhoods affect educational outcomes, relatively little research has explored the mechanisms thought to mediate these effects. This study investigates whether school poverty mediates the effect of neighborhood context on academic achievement. Specifically, it uses longitudinal data from the Panel Study of Income Dynamics, counterfactual methods, and a value-added modeling strategy to estimate the total, natural direct, and natural indirect effects of exposure to an advantaged rather than disadvantaged neighborhood on reading and mathematics abilities during childhood and adolescence. Contrary to expectations, results indicate that school poverty is not a significant mediator of neighborhood effects during either developmental period. Although moving from a disadvantaged neighborhood to an advantaged neighborhood is estimated to substantially reduce subsequent exposure to school poverty and improve academic achievement, school poverty does not play an important mediating role because even the large differences in school composition linked to differences in neighborhood context appear to have no appreciable effect on achievement. An extensive battery of sensitivity analyses indicates that these results are highly robust to unobserved confounding, alternative model specifications, alternative measures of school context, and measurement error, which suggests that neighborhood effects on academic achievement are largely due to mediating factors unrelated to school poverty.

Unsteady mixed convection flow of a micro-polar fluid near the stagnation point on a vertical surface

Energy Technology Data Exchange (ETDEWEB)

Lok, Y.Y. [Center for Academic Services, Kolej Universiti Teknikal Kebangsaan Malaysia, 75450 Ayer Keroh, Melaka (Malaysia); Amin, N. [Department of Mathematics, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Pop, I. [Faculty of Mathematics, University of Cluj, R-3400 Cluj, CP 253 (Romania)

2006-12-15

The unsteady mixed convection boundary-layer flow of a micro-polar fluid near the region of the stagnation point on a double-infinite vertical flat plate is studied. It is assumed that the unsteadiness is caused by the impulsive motion of the free stream velocity and by sudden increase or sudden decrease in the surface temperature from the uniform ambient temperature. The problem is reduced to a system of non-dimensional partial differential equations, which is solved numerically using the Keller-box method. This method may present well-behaved solutions for the transient (small time) solution and those of the steady-state flow (large time) solution. It was found that there is a smooth transition from the small-time solution (initial unsteady-state flow) to the large-time solution (final steady-state flow). Further, it is shown that for both assisting and opposing cases and a fixed value of the Prandtl number, the reduced steady-state skin friction and the steady-state heat transfer from the wall (or Nusselt number) decrease with the increase of the material parameter. On the other hand, it is shown that with the increase of the Prandtl number and a fixed value of the material parameter, the reduced steady-state skin friction decreases when the flow is assisting and it increases when the flow is opposing. (author)

Longitudinal pathways from early maternal depression to children's dysregulated representations: a moderated mediation analysis of harsh parenting and gender.

Science.gov (United States)

Martoccio, Tiffany L; Brophy-Herb, Holly E; Maupin, Angela N; Robinson, Joann L

2016-01-01

There is some evidence linking maternal depression, harsh parenting, and children's internal representations of attachment, yet, longitudinal examinations of these relationships and differences in the developmental pathways between boys and girls are lacking. Moderated mediation growth curves were employed to examine harsh parenting as a mechanism underlying the link between maternal depression and children's dysregulated representations using a nationally-representative, economically-vulnerable sample of mothers and their children (n = 575; 49% boys, 51% girls). Dysregulation representations were measured using the MacArthur Story Stem Battery at five years of age (M = 5.14, SD = 0.29). Harsh parenting mediated the association between early maternal depression and dysregulated representations for girls. Though initial harsh parenting was a significant mediator for boys, a stronger direct effect of maternal depression to dysregulated representations emerged over time. Results are discussed in terms of their implications for intervention efforts aimed at promoting early supportive parenting.

Hepatic deficiency of the pioneer transcription factor FoxA restricts hepatitis B virus biosynthesis by the developmental regulation of viral DNA methylation.

Directory of Open Access Journals (Sweden)

Vanessa C McFadden

2017-02-01

Full Text Available The FoxA family of pioneer transcription factors regulates hepatitis B virus (HBV transcription, and hence viral replication. Hepatocyte-specific FoxA-deficiency in the HBV transgenic mouse model of chronic infection prevents the transcription of the viral DNA genome as a result of the failure of the developmentally controlled conversion of 5-methylcytosine residues to cytosine during postnatal hepatic maturation. These observations suggest that pioneer transcription factors such as FoxA, which mark genes for expression at subsequent developmental steps in the cellular differentiation program, mediate their effects by reversing the DNA methylation status of their target genes to permit their ensuing expression when the appropriate tissue-specific transcription factor combinations arise during development. Furthermore, as the FoxA-deficient HBV transgenic mice are viable, the specific developmental timing, abundance and isoform type of pioneer factor expression must permit all essential liver gene expression to occur at a level sufficient to support adequate liver function. This implies that pioneer transcription factors can recognize and mark their target genes in distinct developmental manners dependent upon, at least in part, the concentration and affinity of FoxA for its binding sites within enhancer and promoter regulatory sequence elements. This selective marking of cellular genes for expression by the FoxA pioneer factor compared to HBV may offer the opportunity for the specific silencing of HBV gene expression and hence the resolution of chronic HBV infections which are responsible for approximately one million deaths worldwide annually due to liver cirrhosis and hepatocellular carcinoma.

Reproductive and developmental toxicology

National Research Council Canada - National Science Library

Gupta, Ramesh C

2011-01-01

.... With a special focus on placental toxicity, this book is the only available reference to connect the three key risk stages, and is the only resource to include reproductive and developmental toxicity in domestic animals, fish, and wildlife.

A Developmental Learning Approach of Mobile Manipulator via Playing

Directory of Open Access Journals (Sweden)

Ruiqi Wu

2017-10-01

Full Text Available Inspired by infant development theories, a robotic developmental model combined with game elements is proposed in this paper. This model does not require the definition of specific developmental goals for the robot, but the developmental goals are implied in the goals of a series of game tasks. The games are characterized into a sequence of game modes based on the complexity of the game tasks from simple to complex, and the task complexity is determined by the applications of developmental constraints. Given a current mode, the robot switches to play in a more complicated game mode when it cannot find any new salient stimuli in the current mode. By doing so, the robot gradually achieves it developmental goals by playing different modes of games. In the experiment, the game was instantiated into a mobile robot with the playing task of picking up toys, and the game is designed with a simple game mode and a complex game mode. A developmental algorithm, “Lift-Constraint, Act and Saturate,” is employed to drive the mobile robot move from the simple mode to the complex one. The experimental results show that the mobile manipulator is able to successfully learn the mobile grasping ability after playing simple and complex games, which is promising in developing robotic abilities to solve complex tasks using games.

Associations of Early Developmental Milestones with Adult Intelligence

Science.gov (United States)

Flensborg-Madsen, Trine; Mortensen, Erik L.

2018-01-01

The study investigated whether age at attainment of 20 developmental milestones within the areas of language, walking, eating, dressing, social interaction, and toilet training was associated with adult intelligence. Mothers of 821 children of the Copenhagen Perinatal Cohort recorded 20 developmental milestones at a 3-year examination, and all…

Instructional Technology Practices in Developmental Education in Texas

Science.gov (United States)

Martirosyan, Nara M.; Kennon, J. Lindsey; Saxon, D. Patrick; Edmonson, Stacey L.; Skidmore, Susan T.

2017-01-01

The purpose of this study was to examine the current state of technology integration in developmental education in Texas higher education. Analyzing survey data from developmental education faculty members in 70 2- and 4-year colleges in Texas, researchers identified instructor-reported best instructional technology practices in developmental…

Treatment of Epilepsy in Children with Developmental Disabilities

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Depositario-Cabacar, Dewi Frances T.; Zelleke, Tesfaye-Getaneh

2010-01-01

Children with developmental disabilities are at increased risk for epilepsy with a prevalence rate higher than the general population. Some of the more common developmental disorders in childhood and the features of epilepsy in these conditions are discussed. Specifically, autism, cerebral palsy, mental retardation, and attention deficit and…

Low functional programming of renal AT2R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure

International Nuclear Information System (INIS)

Ao, Ying; Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na; Li, Bin; Yang, Shuailong; Xia, Liping; Wu, Yong; Wang, Linlong; He, Zheng; Wang, Hui

2015-01-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT 2 R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT 1a R)/AT 2 R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT 2 R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT 2 R might mediate the developmental origin of adult glomerulosclerosis. - Highlights: • Prenatal caffeine exposure induces glomerulosclerosis in adult offspring. • Prenatal caffeine exposure inhibits

Neurobehavioral impairments caused by developmental imidacloprid exposure in zebrafish.

Science.gov (United States)

Crosby, Emily B; Bailey, Jordan M; Oliveri, Anthony N; Levin, Edward D

2015-01-01

Neonicotinoid insecticides are becoming more widely applied as organophosphate (OP) insecticides are decreasing in use. Because of their relative specificity to insect nicotinic receptors, they are thought to have reduced risk of neurotoxicity in vertebrates. However, there is scant published literature concerning the neurobehavioral effects of developmental exposure of vertebrates to neonicotinoids. Using zebrafish, we investigated the neurobehavioral effects of developmental exposure to imidacloprid, a prototypic neonicotinoid pesticide. Nicotine was also administered for comparison. Zebrafish were exposed via immersion in aqueous solutions containing 45 μM or 60 μM of imidacloprid or nicotine (or vehicle control) from 4h to 5d post fertilization. The functional effects of developmental exposure to both imidacloprid and nicotine were assessed in larvae using an activity assay and during adolescence and adulthood using a battery of neurobehavioral assays, including assessment of sensorimotor response and habituation in a tactile startle test, novel tank swimming, and shoaling behavior. In larvae, developmental imidacloprid exposure at both doses significantly decreased swimming activity. The 5D strains of zebrafish were more sensitive to both nicotine and imidacloprid than the AB* strain. In adolescent and adult fish, developmental exposure to imidacloprid significantly decreased novel tank exploration and increased sensorimotor response to startle stimuli. While nicotine did not affect novel tank swimming, it increased sensorimotor response to startle stimuli at the low dose. No effects of either compound were found on shoaling behavior or habituation to a startling stimulus. Early developmental exposure to imidacloprid has both early-life and persisting effects on neurobehavioral function in zebrafish. Its developmental neurotoxicity should be further investigated. Copyright © 2015 Elsevier Inc. All rights reserved.

Intraspecific hybridization, developmental stability and fitness in Drosophila mercatorum

DEFF Research Database (Denmark)

Andersen, D.H.; Pertoldi, C.; Scali, V.

2002-01-01

One of the possible effects of intraspecific hybridization is outbreeding depression, due to a breakdown of coadapted gene complexes, which can lead to reduced fitness and decreased developmental stability in hybrids. Alternatively, increased fitness and increased developmental stability in hybrids...... (hybrid vigour) may be a result of hybridization, probably due to increased heterozygosity. Developmental stability is assumed to be correlated with fitness and is commonly measured as fluctuating asymmetry or phenotypic variance. Drosophila mercatorum is capable of reproducing sexually, but also...

Comparing rat and rabbit embryo-fetal developmental toxicity studies for 379 pharmaceuticals: On systemic dose and developmental effects (Critical Reviews in Toxicology)

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A database of embryo-fetal developmental toxicity (EFDT) studies of 379 pharmaceutical compounds in rat and rabbit was analyzed for species differences based on toxicokinetic parameters of area under the curve (AUC) and maximum concentration (Cmax) at the developmental adverse ef...

The Effectiveness of Tutoring on Developmental English Grades

Science.gov (United States)

Vick, Nicholas; Robles-Piña, Rebecca A.; Martirosyan, Nara M.; Kite, Valerie

2015-01-01

Tutoring is an important form of academic support for developmental education students. A comparison study was conducted to investigate the benefits of tutoring on the final grades for developmental English students who participated in tutoring versus those students who did not. The final grades for three consecutive semesters were analyzed to…