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Sample records for linear growth rates

  1. Testing linear growth rate formulas of non-scale endogenous growth models

    NARCIS (Netherlands)

    Ziesemer, Thomas

    2017-01-01

    Endogenous growth theory has produced formulas for steady-state growth rates of income per capita which are linear in the growth rate of the population. Depending on the details of the models, slopes and intercepts are positive, zero or negative. Empirical tests have taken over the assumption of

  2. Wavelength dependence of the linear growth rate of the Es layer instability

    Directory of Open Access Journals (Sweden)

    R. B. Cosgrove

    2007-06-01

    Full Text Available It has recently been shown, by computation of the linear growth rate, that midlatitude sporadic-E (Es layers are subject to a large scale electrodynamic instability. This instability is a logical candidate to explain certain frontal structuring events, and polarization electric fields, which have been observed in Es layers by ionosondes, by coherent scatter radars, and by rockets. However, the original growth rate derivation assumed an infinitely thin Es layer, and therefore did not address the short wavelength cutoff. Also, the same derivation ignored the effects of F region loading, which is a significant wavelength dependent effect. Herein is given a generalized derivation that remedies both these short comings, and thereby allows a computation of the wavelength dependence of the linear growth rate, as well as computations of various threshold conditions. The wavelength dependence of the linear growth rate is compared with observed periodicities, and the role of the zeroth order meridional wind is explored. A three-dimensional paper model is used to explain the instability geometry, which has been defined formally in previous works.

  3. Linear Stability of Binary Alloy Solidification for Unsteady Growth Rates

    Science.gov (United States)

    Mazuruk, K.; Volz, M. P.

    2010-01-01

    An extension of the Mullins and Sekerka (MS) linear stability analysis to the unsteady growth rate case is considered for dilute binary alloys. In particular, the stability of the planar interface during the initial solidification transient is studied in detail numerically. The rapid solidification case, when the system is traversing through the unstable region defined by the MS criterion, has also been treated. It has been observed that the onset of instability is quite accurately defined by the "quasi-stationary MS criterion", when the growth rate and other process parameters are taken as constants at a particular time of the growth process. A singular behavior of the governing equations for the perturbed quantities at the constitutional supercooling demarcation line has been observed. However, when the solidification process, during its transient, crosses this demarcation line, a planar interface is stable according to the linear analysis performed.

  4. Rate-Independent Processes with Linear Growth Energies and Time-Dependent Boundary Conditions

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2012-01-01

    Roč. 5, č. 3 (2012), s. 591-604 ISSN 1937-1632 R&D Projects: GA AV ČR IAA100750802 Grant - others:GA ČR(CZ) GAP201/10/0357 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * oscillations * time - dependent boundary conditions * rate-independent evolution Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2011/MTR/kruzik-rate-independent processes with linear growth energies and time - dependent boundary conditions.pdf

  5. Beneficial effect of physical activity on linear growth rate of ...

    African Journals Online (AJOL)

    It is not known if nutritional and/or other interventions could improve linear growth in adolescents. The purpose of this study was to assess the role of physical activity in promoting linear growth velocity of black adolescents in a low-income shanty town in South Africa. Two schools in a disadvantaged shanty town participated ...

  6. Linear growth rates of resistive tearing modes with sub-Alfvénic streaming flow

    International Nuclear Information System (INIS)

    Wu, L. N.; Ma, Z. W.

    2014-01-01

    The tearing instability with sub-Alfvénic streaming flow along the external magnetic field is investigated using resistive MHD simulation. It is found that the growth rate of the tearing mode instability is larger than that without the streaming flow. With the streaming flow, there exist two Alfvén resonance layers near the central current sheet. The larger perturbation of the magnetic field in two closer Alfvén resonance layers could lead to formation of the observed cone structure and can largely enhance the development of the tearing mode for a narrower streaming flow. For a broader streaming flow, a larger separation of Alfvén resonance layers reduces the magnetic reconnection. The linear growth rate decreases with increase of the streaming flow thickness. The growth rate of the tearing instability also depends on the plasma beta (β). When the streaming flow is embedded in the current sheet, the growth rate increases with β if β  s , but decreases if β > β s . The existence of the specific value β s can be attributed to competition between the suppressing effect of β and the enhancing effect of the streaming flow on the magnetic reconnection. The critical value β s increases with increase of the streaming flow strength

  7. Linear growth of the entanglement entropy and the Kolmogorov-Sinai rate

    Science.gov (United States)

    Bianchi, Eugenio; Hackl, Lucas; Yokomizo, Nelson

    2018-03-01

    The rate of entropy production in a classical dynamical system is characterized by the Kolmogorov-Sinai entropy rate h KS given by the sum of all positive Lyapunov exponents of the system. We prove a quantum version of this result valid for bosonic systems with unstable quadratic Hamiltonian. The derivation takes into account the case of time-dependent Hamiltonians with Floquet instabilities. We show that the entanglement entropy S A of a Gaussian state grows linearly for large times in unstable systems, with a rate Λ A ≤ h KS determined by the Lyapunov exponents and the choice of the subsystem A. We apply our results to the analysis of entanglement production in unstable quadratic potentials and due to periodic quantum quenches in many-body quantum systems. Our results are relevant for quantum field theory, for which we present three applications: a scalar field in a symmetry-breaking potential, parametric resonance during post-inflationary reheating and cosmological perturbations during inflation. Finally, we conjecture that the same rate Λ A appears in the entanglement growth of chaotic quantum systems prepared in a semiclassical state.

  8. On conjugacy growth of linear groups

    OpenAIRE

    Breuillard, Emmanuel; de Cornulier, Yves; Lubotzky, Alexander; Meiri, Chen

    2011-01-01

    We investigate the conjugacy growth of finitely generated linear groups. We show that finitely generated non-virtually-solvable subgroups of GL_d have uniform exponential conjugacy growth and in fact that the number of distinct polynomials arising as characteristic polynomials of the elements of the ball of radius n for the word metric has exponential growth rate bounded away from 0 in terms of the dimension d only.

  9. The Non-Linear Effect of Corporate Taxes on Economic Growth

    Directory of Open Access Journals (Sweden)

    Huňady Ján

    2015-03-01

    Full Text Available The paper deals with the problem of taxation and its potential impact on economic growth and presents some new empirical insights into this topic. The main aim of the paper is to verify an assumed nonlinear impact of corporate tax rates on economic growth. Based on the theory of public finance and taxation, we hypothesize that at relatively low tax rates it is possible that the impact of taxation on economic growth become slightly positive. On the other hand when the tax rates are higher a negative impact of taxation on economic growth could be expected. Despite the fact that the most of the existing studies find a negative linear relationship between these variables, we can also find strong support for a non-linear relationship from several theoretical models as well as some empirical studies. Based on panel data fixed-effects econometric models, we, as well, find empirical evidence for a non-linear relationship between nominal and effective corporate tax rates and economic growth. Our data consists of annual observations for the period 1999 to 2011 for EU Member States. Based on the results, we also estimated the optimal level of the corporate tax rate in terms of maximizing economic growth in the average of the EU countries.

  10. Influence of magnetic flutter on tearing growth in linear and nonlinear theory

    Science.gov (United States)

    Kreifels, L.; Hornsby, W. A.; Weikl, A.; Peeters, A. G.

    2018-06-01

    Recent simulations of tearing modes in turbulent regimes show an unexpected enhancement in the growth rate. In this paper the effect is investigated analytically. The enhancement is linked to the influence of turbulent magnetic flutter, which is modelled by diffusion terms in magnetohydrodynamics (MHD) momentum balance and Ohm’s law. Expressions for the linear growth rate as well as the island width in nonlinear theory for small amplitudes are derived. The results indicate an enhanced linear growth rate and a larger linear layer width compared with resistive MHD. Also the island width in the nonlinear regime grows faster in the diffusive model. These observations correspond well to simulations in which the effect of turbulence on the magnetic island width and tearing mode growth is analyzed.

  11. Piecewise Linear-Linear Latent Growth Mixture Models with Unknown Knots

    Science.gov (United States)

    Kohli, Nidhi; Harring, Jeffrey R.; Hancock, Gregory R.

    2013-01-01

    Latent growth curve models with piecewise functions are flexible and useful analytic models for investigating individual behaviors that exhibit distinct phases of development in observed variables. As an extension of this framework, this study considers a piecewise linear-linear latent growth mixture model (LGMM) for describing segmented change of…

  12. Coral growth rates revisited after 31 years: what is causing lower extension rates in Acropora palmata?

    NARCIS (Netherlands)

    Bak, R.P.M.; Nieuwland, G.; Meesters, H.W.G.

    2009-01-01

    Linear extension of branches in the same Acropora palmata (Lamarck, 1816) population in Curaçao was measured, employing exactly the same methods, in 1971-1973 and in 2002-2004, and the resulting coral growth rates are compared. Linear growth shows the same pattern over seasons in both periods with

  13. Allometries of Maximum Growth Rate versus Body Mass at Maximum Growth Indicate That Non-Avian Dinosaurs Had Growth Rates Typical of Fast Growing Ectothermic Sauropsids

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case’s study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either

  14. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case's study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either of

  15. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Directory of Open Access Journals (Sweden)

    Jan Werner

    Full Text Available We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes strongly differed from Case's study (1978, which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles to 20 (fishes times (in comparison to mammals or even 45 (reptiles to 100 (fishes times (in comparison to birds lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule

  16. Emittance growth rates for displaced beams

    International Nuclear Information System (INIS)

    Anderson, O.A.

    1993-05-01

    Emittance growth rates have been previously analyzed for nonuniform beams in linear channels and for initially uniform mismatched beams in nonlinear channels. These studies were for centered beams. Additional emittance growth can arise in cases where the beam is initially displaced. The purpose of this study is to obtain growth rates for displaced beams. This work differs from studies involving random displacement of electrodes. Our analysis assumes instead that the focusing system is perfectly aligned but that the beam is initially displaced with respect to the equilibrium axis. If the focusing force is slightly nonlinear, we find a gradual transfer of the potential energy of beam displacement into kinetic energy associated with emittance growth. We present explicit results for the emittance growth distance as a function of the nonlinearity of the channel. These results will have practical importance for designers of accelerators and transport systems when setting realistic tolerances for initial beam alignment. These tolerances will depend on the nonlinearity and the length of the system

  17. The effects of oestrogens on linear bone growth

    DEFF Research Database (Denmark)

    Juul, A

    2001-01-01

    Regulation of linear bone growth in children and adolescents comprises a complex interaction of hormones and growth factors. Growth hormone (GH) is considered to be the key hormone regulator of linear growth in childhood. The pubertal increase in growth velocity associated with GH has traditionally...... been attributed to testicular androgen secretion in boys, and to oestrogens or adrenal androgen secretion in girls. Research data indicating that oestrogen may be the principal hormone stimulating the pubertal growth spurt in boys as well as girls is reviewed. Such an action is mediated by oestrogen...... female growth spurt despite lack of androgen action. Oestrogens may also influence linear bone growth indirectly via modulation of the GH-insulin-like growth factor-I (IGF-I) axis. Thus, ER blockade diminishes endogenous GH secretion, androgen receptor (AR) blockade increases GH secretion in peripubertal...

  18. Non-compliance with growth hormone treatment in children is common and impairs linear growth.

    Directory of Open Access Journals (Sweden)

    Wayne S Cutfield

    Full Text Available BACKGROUND: GH therapy requires daily injections over many years and compliance can be difficult to sustain. As growth hormone (GH is expensive, non-compliance is likely to lead to suboptimal growth, at considerable cost. Thus, we aimed to assess the compliance rate of children and adolescents with GH treatment in New Zealand. METHODS: This was a national survey of GH compliance, in which all children receiving government-funded GH for a four-month interval were included. Compliance was defined as ≥ 85% adherence (no more than one missed dose a week on average to prescribed treatment. Compliance was determined based on two parameters: either the number of GH vials requested (GHreq by the family or the number of empty GH vials returned (GHret. Data are presented as mean ± SEM. FINDINGS: 177 patients were receiving GH in the study period, aged 12.1 ± 0.6 years. The rate of returned vials, but not number of vials requested, was positively associated with HVSDS (p < 0.05, such that patients with good compliance had significantly greater linear growth over the study period (p<0.05. GHret was therefore used for subsequent analyses. 66% of patients were non-compliant, and this outcome was not affected by sex, age or clinical diagnosis. However, Maori ethnicity was associated with a lower rate of compliance. INTERPRETATION: An objective assessment of compliance such as returned vials is much more reliable than compliance based on parental or patient based information. Non-compliance with GH treatment is common, and associated with reduced linear growth. Non-compliance should be considered in all patients with apparently suboptimal response to GH treatment.

  19. Why care about linear hair growth rates (LHGR)? a study using in vivo imaging and computer assisted image analysis after manual processing (CAIAMP) in unaffected male controls and men with male pattern hair loss (MPHL).

    Science.gov (United States)

    Van Neste, Dominique

    2014-01-01

    The words "hair growth" frequently encompass many aspects other than just growth. Report on a validation method for precise non-invasive measurement of thickness together with linear hair growth rates of individual hair fibres. To verify the possible correlation between thickness and linear growth rate of scalp hair in male pattern hair loss as compared with healthy male controls. To document the process of validation of hair growth measurement from in vivo image capturing and manual processing, followed by computer assisted image analysis. We analysed 179 paired images obtained with the contrast-enhanced-phototrichogram method with exogen collection (CE-PTG-EC) in 13 healthy male controls and in 87 men with male pattern hair loss (MPHL). There was a global positive correlation between thickness and growth rate (ANOVA; phairs from controls. Finally, the growth rate recorded in the more severe patterns was significantly (ANOVA; P ≤ 0.001) reduced compared with equally thick hair from less severely affected MPHL or controls subjects. Reduced growth rate, together with thinning and shortening of the anagen phase duration in MPHL might contribute together to the global impression of decreased hair volume on the top of the head. Amongst other structural and functional parameters characterizing hair follicle regression, linear hair growth rate warrants further investigation, as it may be relevant in terms of self-perception of hair coverage, quantitative diagnosis and prognostic factor of the therapeutic response.

  20. Vertical instability in TCV: comparison of experimental and theoretical growth rates

    International Nuclear Information System (INIS)

    Hofmann, F.; Dutch, M.J.; Ward, D.J.; Anton, M.; Furno, I.; Lister, J.B.; Moret, J.M.

    1996-12-01

    Growth rates of the axisymmetric mode in vertically elongated plasmas in the TCV tokamak are measured and compared with numerically calculated growth rates for the reconstructed equilibria. This comparison is made over a range of discharge parameters including elongation, triangularity, and vertical position within the vacuum vessel. Growth rates increase with respect to increasing elongation, decreasing triangularity and increasing vertical distance from the top of the vacuum vessel, as expected. The agreement between the measured growth rates in the experiment and the numerically determined growth rates is excellent, in particular for the full linear MHD model which accounts for the non-rigid motion of strongly shaped plasma cross-sections. (author) 7 figs., 22 refs

  1. Growth rate in the dynamical dark energy models

    International Nuclear Information System (INIS)

    Avsajanishvili, Olga; Arkhipova, Natalia A.; Samushia, Lado; Kahniashvili, Tina

    2014-01-01

    Dark energy models with a slowly rolling cosmological scalar field provide a popular alternative to the standard, time-independent cosmological constant model. We study the simultaneous evolution of background expansion and growth in the scalar field model with the Ratra-Peebles self-interaction potential. We use recent measurements of the linear growth rate and the baryon acoustic oscillation peak positions to constrain the model parameter α that describes the steepness of the scalar field potential. (orig.)

  2. Growth rate in the dynamical dark energy models.

    Science.gov (United States)

    Avsajanishvili, Olga; Arkhipova, Natalia A; Samushia, Lado; Kahniashvili, Tina

    Dark energy models with a slowly rolling cosmological scalar field provide a popular alternative to the standard, time-independent cosmological constant model. We study the simultaneous evolution of background expansion and growth in the scalar field model with the Ratra-Peebles self-interaction potential. We use recent measurements of the linear growth rate and the baryon acoustic oscillation peak positions to constrain the model parameter [Formula: see text] that describes the steepness of the scalar field potential.

  3. Nd isotopes and crustal growth rate

    International Nuclear Information System (INIS)

    Albarede, F.

    1988-01-01

    Sm/Nd isotopic constraints on crustal growth is discussed. In order to constrain Sm/Nd fractionation between continental crust and depleted mantle, an extensive data base of isotopic measurements (assumed to be adequately representative of continental crust) was compiled. The results imply that the evolution of depleted mantles was roughly linear, with no major discontinuities over the course of geologic time. This is different from other determinations of depleting mantle evolution, which show nonlinear behavior. The Sm/Nd evolution lines for continental crust and depleted mantle intersect between 3.8 to 4.0 Ga, which may indicate that the onset of continental growth was later than 4.5 Ga. A mathematical model is described, the results of which imply that time integrated crustal additions from the mantle are about 1.8 to 2.5 cu km/a, whereas crustal subtractions by sediment recycling are about 0.6 to 1.5 cu km/a. This results in a net time integrated crustal growth rate of about 1 cu km/a, which is similar to present day rates determined, for example, by Reymer and Schubert

  4. Non-linear Growth Models in Mplus and SAS

    Science.gov (United States)

    Grimm, Kevin J.; Ram, Nilam

    2013-01-01

    Non-linear growth curves or growth curves that follow a specified non-linear function in time enable researchers to model complex developmental patterns with parameters that are easily interpretable. In this paper we describe how a variety of sigmoid curves can be fit using the Mplus structural modeling program and the non-linear mixed-effects modeling procedure NLMIXED in SAS. Using longitudinal achievement data collected as part of a study examining the effects of preschool instruction on academic gain we illustrate the procedures for fitting growth models of logistic, Gompertz, and Richards functions. Brief notes regarding the practical benefits, limitations, and choices faced in the fitting and estimation of such models are included. PMID:23882134

  5. Pretreatment Growth Rate Predicts Radiation Response in Vestibular Schwannomas

    International Nuclear Information System (INIS)

    Niu, Nina N.; Niemierko, Andrzej; Larvie, Mykol; Curtin, Hugh; Loeffler, Jay S.; McKenna, Michael J.; Shih, Helen A.

    2014-01-01

    Purpose: Vestibular schwannomas (VS) are often followed without initial therapeutic intervention because many tumors do not grow and radiation therapy is associated with potential adverse effects. In an effort to determine whether maximizing initial surveillance predicts for later treatment response, the predictive value of preirradiation growth rate of VS on response to radiation therapy was assessed. Methods and Materials: Sixty-four patients with 65 VS were treated with single-fraction stereotactic radiation surgery or fractionated stereotactic radiation therapy. Pre- and postirradiation linear expansion rates were estimated using volumetric measurements on sequential magnetic resonance images (MRIs). In addition, postirradiation tumor volume change was classified as demonstrating shrinkage (ratio of volume on last follow-up MRI to MRI immediately preceding irradiation <80%), stability (ratio 80%-120%), or expansion (ratio >120%). The median pre- and postirradiation follow-up was 20.0 and 27.5 months, respectively. Seven tumors from neurofibromatosis type 2 (NF2) patients were excluded from statistical analyses. Results: In the 58 non-NF2 patients, there was a trend of correlation between pre- and postirradiation volume change rates (slope on linear regression, 0.29; P=.06). Tumors demonstrating postirradiation expansion had a median preirradiation growth rate of 89%/year, and those without postirradiation expansion had a median preirradiation growth rate of 41%/year (P=.02). As the preirradiation growth rate increased, the probability of postirradiation expansion also increased. Overall, 24.1% of tumors were stable, 53.4% experienced shrinkage, and 22.5% experienced expansion. Predictors of no postirradiation tumor expansion included no prior surgery (P=.01) and slower tumor growth rate (P=.02). The control of tumors in NF2 patients was only 43%. Conclusions: Radiation therapy is an effective treatment for VS, but tumors that grow quickly preirradiation may be

  6. Pretreatment Growth Rate Predicts Radiation Response in Vestibular Schwannomas

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Nina N. [Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Department of Medicine, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Niemierko, Andrzej [Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts (United States); Larvie, Mykol [Harvard Medical School, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts (United States); Curtin, Hugh [Harvard Medical School, Department of Radiology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts (United States); Loeffler, Jay S. [Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts (United States); McKenna, Michael J. [Harvard Medical School, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-05-01

    Purpose: Vestibular schwannomas (VS) are often followed without initial therapeutic intervention because many tumors do not grow and radiation therapy is associated with potential adverse effects. In an effort to determine whether maximizing initial surveillance predicts for later treatment response, the predictive value of preirradiation growth rate of VS on response to radiation therapy was assessed. Methods and Materials: Sixty-four patients with 65 VS were treated with single-fraction stereotactic radiation surgery or fractionated stereotactic radiation therapy. Pre- and postirradiation linear expansion rates were estimated using volumetric measurements on sequential magnetic resonance images (MRIs). In addition, postirradiation tumor volume change was classified as demonstrating shrinkage (ratio of volume on last follow-up MRI to MRI immediately preceding irradiation <80%), stability (ratio 80%-120%), or expansion (ratio >120%). The median pre- and postirradiation follow-up was 20.0 and 27.5 months, respectively. Seven tumors from neurofibromatosis type 2 (NF2) patients were excluded from statistical analyses. Results: In the 58 non-NF2 patients, there was a trend of correlation between pre- and postirradiation volume change rates (slope on linear regression, 0.29; P=.06). Tumors demonstrating postirradiation expansion had a median preirradiation growth rate of 89%/year, and those without postirradiation expansion had a median preirradiation growth rate of 41%/year (P=.02). As the preirradiation growth rate increased, the probability of postirradiation expansion also increased. Overall, 24.1% of tumors were stable, 53.4% experienced shrinkage, and 22.5% experienced expansion. Predictors of no postirradiation tumor expansion included no prior surgery (P=.01) and slower tumor growth rate (P=.02). The control of tumors in NF2 patients was only 43%. Conclusions: Radiation therapy is an effective treatment for VS, but tumors that grow quickly preirradiation may be

  7. Describing Growth Pattern of Bali Cows Using Non-linear Regression Models

    Directory of Open Access Journals (Sweden)

    Mohd. Hafiz A.W

    2016-12-01

    Full Text Available The objective of this study was to evaluate the best fit non-linear regression model to describe the growth pattern of Bali cows. Estimates of asymptotic mature weight, rate of maturing and constant of integration were derived from Brody, von Bertalanffy, Gompertz and Logistic models which were fitted to cross-sectional data of body weight taken from 74 Bali cows raised in MARDI Research Station Muadzam Shah Pahang. Coefficient of determination (R2 and residual mean squares (MSE were used to determine the best fit model in describing the growth pattern of Bali cows. Von Bertalanffy model was the best model among the four growth functions evaluated to determine the mature weight of Bali cattle as shown by the highest R2 and lowest MSE values (0.973 and 601.9, respectively, followed by Gompertz (0.972 and 621.2, respectively, Logistic (0.971 and 648.4, respectively and Brody (0.932 and 660.5, respectively models. The correlation between rate of maturing and mature weight was found to be negative in the range of -0.170 to -0.929 for all models, indicating that animals of heavier mature weight had lower rate of maturing. The use of non-linear model could summarize the weight-age relationship into several biologically interpreted parameters compared to the entire lifespan weight-age data points that are difficult and time consuming to interpret.

  8. Skeletal muscle protein accretion rates and hindlimb growth are reduced in late gestation intrauterine growth-restricted fetal sheep.

    Science.gov (United States)

    Rozance, Paul J; Zastoupil, Laura; Wesolowski, Stephanie R; Goldstrohm, David A; Strahan, Brittany; Cree-Green, Melanie; Sheffield-Moore, Melinda; Meschia, Giacomo; Hay, William W; Wilkening, Randall B; Brown, Laura D

    2018-01-01

    Adults who were affected by intrauterine growth restriction (IUGR) suffer from reductions in muscle mass, which may contribute to insulin resistance and the development of diabetes. We demonstrate slower hindlimb linear growth and muscle protein synthesis rates that match the reduced hindlimb blood flow and oxygen consumption rates in IUGR fetal sheep. These adaptations resulted in hindlimb blood flow rates in IUGR that were similar to control fetuses on a weight-specific basis. Net hindlimb glucose uptake and lactate output rates were similar between groups, whereas amino acid uptake was significantly lower in IUGR fetal sheep. Among all fetuses, blood O 2 saturation and plasma glucose, insulin and insulin-like growth factor-1 were positively associated and norepinephrine was negatively associated with hindlimb weight. These results further our understanding of the metabolic and hormonal adaptations to reduced oxygen and nutrient supply with placental insufficiency that develop to slow hindlimb growth and muscle protein accretion. Reduced skeletal muscle mass in the fetus with intrauterine growth restriction (IUGR) persists into adulthood and may contribute to increased metabolic disease risk. To determine how placental insufficiency with reduced oxygen and nutrient supply to the fetus affects hindlimb blood flow, substrate uptake and protein accretion rates in skeletal muscle, late gestation control (CON) (n = 8) and IUGR (n = 13) fetal sheep were catheterized with aortic and femoral catheters and a flow transducer around the external iliac artery. Muscle protein kinetic rates were measured using isotopic tracers. Hindlimb weight, linear growth rate, muscle protein accretion rate and fractional synthetic rate were lower in IUGR compared to CON (P fetal norepinephrine and reduced IGF-1 and insulin. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  9. The effects of oestrogens on linear bone growth

    DEFF Research Database (Denmark)

    Juul, A

    2001-01-01

    receptors (ER-alpha and ER-beta) in the human growth plate, and polymorphisms in the ER gene may influence adult height in healthy subjects. Prepubertal oestradiol concentrations are significantly higher in girls than in boys, explaining sex-related differences in pubertal onset. Men with a disruptive......Regulation of linear bone growth in children and adolescents comprises a complex interaction of hormones and growth factors. Growth hormone (GH) is considered to be the key hormone regulator of linear growth in childhood. The pubertal increase in growth velocity associated with GH has traditionally...... been attributed to testicular androgen secretion in boys, and to oestrogens or adrenal androgen secretion in girls. Research data indicating that oestrogen may be the principal hormone stimulating the pubertal growth spurt in boys as well as girls is reviewed. Such an action is mediated by oestrogen...

  10. Modelling of tomato stem diameter growth rate based on physiological responses

    International Nuclear Information System (INIS)

    Li, L.; Tan, J.; Lv, T.

    2017-01-01

    The stem diameter is an important parameter describing the growth of tomato plant during vegetative growth stage. A stem diameter growth model was developed to predict the response of plant growth under different conditions. By analyzing the diurnal variations of stem diameter in tomato (Solanum lycopersicum L.), it was found that the stem diameter measured at 3:00 am was the representative value as the daily basis of tomato stem diameter. Based on the responses of growth rate in stem diameter to light and temperature, a linear regression relationship was applied to establish the stem diameter growth rate prediction model for the vegetative growth stage in tomato and which was further validated by experiment. The root mean square error (RMSE) and relative error (RE) were used to test the correlation between measured and modeled stem diameter variations. Results showed that the model can be used in prediction for stem diameter growth rate at vegetative growth stage in tomato. (author)

  11. A review on pipeline corrosion, in-line inspection (ILI), and corrosion growth rate models

    International Nuclear Information System (INIS)

    Vanaei, H.R.; Eslami, A.; Egbewande, A.

    2017-01-01

    Pipelines are the very important energy transmission systems. Over time, pipelines can corrode. While corrosion could be detected by in-line inspection (ILI) tools, corrosion growth rate prediction in pipelines is usually done through corrosion rate models. For pipeline integrity management and planning selecting the proper corrosion ILI tool and also corrosion growth rate model is important and can lead to significant savings and safer pipe operation. In this paper common forms of pipeline corrosion, state of the art ILI tools, and also corrosion growth rate models are reviewed. The common forms of pipeline corrosion introduced in this paper are Uniform/General Corrosion, Pitting Corrosion, Cavitation and Erosion Corrosion, Stray Current Corrosion, Micro-Bacterial Influenced Corrosion (MIC). The ILI corrosion detection tools assessed in this study are Magnetic Flux Leakage (MFL), Circumferential MFL, Tri-axial MFL, and Ultrasonic Wall Measurement (UT). The corrosion growth rate models considered in this study are single-value corrosion rate model, linear corrosion growth rate model, non-linear corrosion growth rate model, Monte-Carlo method, Markov model, TD-GEVD, TI-GEVD model, Gamma Process, and BMWD model. Strengths and limitations of ILI detection tools, and also corrosion predictive models with some practical examples are discussed. This paper could be useful for those whom are supporting pipeline integrity management and planning. - Highlights: • Different forms of pipeline corrosion are explained. • Common In-Line Inspection (ILI) tools and corrosion growth rate models are introduced. • Strength and limitations of corrosion growth rate models/ILI tools are discussed. • For pipeline integrity management programs using more than one corrosion growth rate model/ILI tool is suggested.

  12. Dietary arginine and linear growth

    DEFF Research Database (Denmark)

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W

    2013-01-01

    Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept......The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School...... and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity...

  13. The effect of changes in sea surface temperature on linear growth of Porites coral in Ambon Bay

    International Nuclear Information System (INIS)

    Corvianawatie, Corry; Putri, Mutiara R.; Cahyarini, Sri Y.

    2015-01-01

    Coral is one of the most important organisms in the coral reef ecosystem. There are several factors affecting coral growth, one of them is changes in sea surface temperature (SST). The purpose of this research is to understand the influence of SST variability on the annual linear growth of Porites coral taken from Ambon Bay. The annual coral linear growth was calculated and compared to the annual SST from the Extended Reconstructed Sea Surface Temperature version 3b (ERSST v3b) model. Coral growth was calculated by using Coral X-radiograph Density System (CoralXDS) software. Coral sample X-radiographs were used as input data. Chronology was developed by calculating the coral’s annual growth bands. A pair of high and low density banding patterns observed in the coral’s X-radiograph represent one year of coral growth. The results of this study shows that Porites coral extents from 2001-2009 and had an average growth rate of 1.46 cm/year. Statistical analysis shows that the annual coral linear growth declined by 0.015 cm/year while the annual SST declined by 0.013°C/year. SST and the annual linear growth of Porites coral in the Ambon Bay is insignificantly correlated with r=0.304 (n=9, p>0.05). This indicates that annual SST variability does not significantly influence the linear growth of Porites coral from Ambon Bay. It is suggested that sedimentation load, salinity, pH or other environmental factors may affect annual linear coral growth

  14. The effect of changes in sea surface temperature on linear growth of Porites coral in Ambon Bay

    Energy Technology Data Exchange (ETDEWEB)

    Corvianawatie, Corry, E-mail: corvianawatie@students.itb.ac.id; Putri, Mutiara R., E-mail: mutiara.putri@fitb.itb.ac.id [Oceanography Study Program, Bandung Institute of Technology (ITB), Jl. Ganesha 10 Bandung (Indonesia); Cahyarini, Sri Y., E-mail: yuda@geotek.lipi.go.id [Research Center for Geotechnology, Indonesian Institute of Sciences (LIPI), Bandung (Indonesia)

    2015-09-30

    Coral is one of the most important organisms in the coral reef ecosystem. There are several factors affecting coral growth, one of them is changes in sea surface temperature (SST). The purpose of this research is to understand the influence of SST variability on the annual linear growth of Porites coral taken from Ambon Bay. The annual coral linear growth was calculated and compared to the annual SST from the Extended Reconstructed Sea Surface Temperature version 3b (ERSST v3b) model. Coral growth was calculated by using Coral X-radiograph Density System (CoralXDS) software. Coral sample X-radiographs were used as input data. Chronology was developed by calculating the coral’s annual growth bands. A pair of high and low density banding patterns observed in the coral’s X-radiograph represent one year of coral growth. The results of this study shows that Porites coral extents from 2001-2009 and had an average growth rate of 1.46 cm/year. Statistical analysis shows that the annual coral linear growth declined by 0.015 cm/year while the annual SST declined by 0.013°C/year. SST and the annual linear growth of Porites coral in the Ambon Bay is insignificantly correlated with r=0.304 (n=9, p>0.05). This indicates that annual SST variability does not significantly influence the linear growth of Porites coral from Ambon Bay. It is suggested that sedimentation load, salinity, pH or other environmental factors may affect annual linear coral growth.

  15. On the growth rate of gallstones in the human gallbladder

    Science.gov (United States)

    Nudelman, I.

    1993-05-01

    The growth rate of a single symmetrically oval shaped gallbladder stone weighing 10.8 g was recorded over a period of six years before surgery and removal. The length of the stone was measured by ultrasonography and the growth rate was found to be linear with time, with a value of 0.4 mm/year. A smaller stone growing in the wall of the gallbladder was detected only three years before removal and grew at a rate of ˜ 1.33 mm/year. The morphology and metallic ion chemical composition of the large stone and of a randomly selected small stone weighing about 1.1 g, extracted from another patient, were analyzed and compared. It was found that the large stone contained besides calcium also lead, whereas the small stone contained mainly calcium. It is possible that the lead causes a difference in mechanism between the growth of a single large and growth of multiple small gallstones.

  16. Convex variational problems linear, nearly linear and anisotropic growth conditions

    CERN Document Server

    Bildhauer, Michael

    2003-01-01

    The author emphasizes a non-uniform ellipticity condition as the main approach to regularity theory for solutions of convex variational problems with different types of non-standard growth conditions. This volume first focuses on elliptic variational problems with linear growth conditions. Here the notion of a "solution" is not obvious and the point of view has to be changed several times in order to get some deeper insight. Then the smoothness properties of solutions to convex anisotropic variational problems with superlinear growth are studied. In spite of the fundamental differences, a non-uniform ellipticity condition serves as the main tool towards a unified view of the regularity theory for both kinds of problems.

  17. Caregiver perceptions of children's linear growth in Bangladesh: a qualitative analysis.

    Science.gov (United States)

    Hossain, Muttaquina; Ickes, Scott; Rice, Lauren; Ritter, Gaelen; Naila, Nurun Nahar; Zia, Tasnia; Nahar, Baitun; Mahfuz, Mustafa; Denno, Donna M; Ahmed, Tahmeed; Walson, Judd

    2018-03-26

    To understand caregivers' perceptions of children's linear growth and to identify the cultural meanings and perceptions of risk associated with poor height attainment. Three investigators from Bangladesh conducted twelve focus group discussions. The study was conducted in rural and slum settings in Bangladesh. Participants included mothers and alternative caregivers (n 81) who were recruited by household screening. No eligible, recruited subjects refused participation. Caregivers reported limited experience with growth monitoring services from the health system. Caregivers mainly use visual cues and developmental milestones to understand if children are growing properly, and recognize that children normally experience both weight gain and linear growth with age. Mothers expressed concern over children's malnutrition and short stature, but did not discuss children's failure to attain a 'growth potential' or distinguish inherited short stature from stunting. Caregivers interpret the consequences of poor height attainment as primarily social and economic and cite few health risks. Linear growth interpretation is determined more by community norms than by guidance from nutrition programming or the health system. Interventions to prevent or reduce linear growth failure may be perceived to have limited value where appropriate linear growth in children is determined by comparison to peers and siblings. Such perceptions may be significant barriers to programmes addressing stunting prevention in settings where many children are stunted. Efforts to raise awareness about the risks of linear growth faltering may need to consider delivering messages to caregivers that emphasize the social and economic consequences of stunting.

  18. Conifers in cold environments synchronize maximum growth rate of tree-ring formation with day length.

    Science.gov (United States)

    Rossi, Sergio; Deslauriers, Annie; Anfodillo, Tommaso; Morin, Hubert; Saracino, Antonio; Motta, Renzo; Borghetti, Marco

    2006-01-01

    Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote (A), x-axis placement (beta) and rate of change (kappa). A strong linear relationship was found between the constants beta and kappa for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter.

  19. Accretion of Fat-Free Mass Rather Than Fat Mass in Infancy Is Positively Associated with Linear Growth in Childhood.

    Science.gov (United States)

    Admassu, Bitiya; Ritz, Christian; Wells, Jonathan C K; Girma, Tsinuel; Andersen, Gregers S; Belachew, Tefera; Owino, Victor; Michaelsen, Kim F; Abera, Mubarek; Wibaek, Rasmus; Friis, Henrik; Kæstel, Pernille

    2018-04-01

    We have previously shown that fat-free mass (FFM) at birth is associated with height at 2 y of age in Ethiopian children. However, to our knowledge, the relation between changes in body composition during early infancy and later linear growth has not been studied. This study examined the associations of early infancy fat mass (FM) and FFM accretion with linear growth from 1 to 5 y of age in Ethiopian children. In the infant Anthropometry and Body Composition (iABC) study, a prospective cohort study was carried out in children in Jimma, Ethiopia, followed from birth to 5 y of age. FM and FFM were measured ≤6 times from birth to 6 mo by using air-displacement plethysmography. Linear mixed-effects models were used to identify associations between standardized FM and FFM accretion rates during early infancy and linear growth from 1 to 5 y of age. Standardized accretion rates were obtained by dividing FM and FFM accretion by their respective SD. FFM accretion from 0 to 6 mo of age was positively associated with length at 1 y (β = 0.64; 95% CI: 0.19, 1.09; P = 0.005) and linear growth from 1 to 5 y (β = 0.63; 95% CI: 0.19, 1.07; P = 0.005). The strongest association with FFM accretion was observed at 1 y. The association with linear growth from 1 to 5 y was mainly engendered by the 1-y association. FM accretion from 0 to 4 mo was positively associated with linear growth from 1 to 5 y (β = 0.45; 95% CI: 0.02, 0.88; P = 0.038) in the fully adjusted model. In Ethiopian children, FFM accretion was associated with linear growth at 1 y and no clear additional longitudinal effect from 1 to 5 y was observed. FM accretion showed a weak association from 1 to 5 y. This trial was registered at www.controlled-trials.com as ISRCTN46718296.

  20. Methods of forecasting crack growth rate under creep conditions

    International Nuclear Information System (INIS)

    Ol'kin, S.I.

    1979-01-01

    Using construction aluminium alloy application possibility of linear mechanics of the destruction for quantitative description of crack development process under creepage conditions is investigated. It is shown, that the grade dependence between the stress intensity coefficient and the crack growth rate takes place only at certain combination of the sample geometry and creepage parameters, and consequently, its applicability in every given case must necessarily be tested experimentally

  1. McDonald Generalized Linear Failure Rate Distribution

    Directory of Open Access Journals (Sweden)

    Ibrahim Elbatal

    2014-10-01

    Full Text Available We introduce in this paper a new six-parameters generalized version of the generalized linear failure rate (GLFR distribution which is called McDonald Generalized Linear failure rate (McGLFR distribution. The new distribution is quite flexible and can be used effectively in modeling survival data and reliability problems. It can have a constant, decreasing, increasing, and upside down bathtub-and bathtub shaped failure rate function depending on its parameters. It includes some well-known lifetime distributions as special sub-models. Some structural properties of the new distribution are studied. Moreover we discuss maximum likelihood estimation of the unknown parameters of the new model.

  2. Miniaturized Stretchable and High-Rate Linear Supercapacitors

    OpenAIRE

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-01-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electr...

  3. Estimating monotonic rates from biological data using local linear regression.

    Science.gov (United States)

    Olito, Colin; White, Craig R; Marshall, Dustin J; Barneche, Diego R

    2017-03-01

    Accessing many fundamental questions in biology begins with empirical estimation of simple monotonic rates of underlying biological processes. Across a variety of disciplines, ranging from physiology to biogeochemistry, these rates are routinely estimated from non-linear and noisy time series data using linear regression and ad hoc manual truncation of non-linearities. Here, we introduce the R package LoLinR, a flexible toolkit to implement local linear regression techniques to objectively and reproducibly estimate monotonic biological rates from non-linear time series data, and demonstrate possible applications using metabolic rate data. LoLinR provides methods to easily and reliably estimate monotonic rates from time series data in a way that is statistically robust, facilitates reproducible research and is applicable to a wide variety of research disciplines in the biological sciences. © 2017. Published by The Company of Biologists Ltd.

  4. Rate of Language Growth in Children with Hearing Loss in an Auditory-Verbal Early Intervention Program

    Science.gov (United States)

    Jackson, Carla Wood; Schatschneider, Christopher

    2013-01-01

    This longitudinal study explored the rate of language growth of children in an early intervention program providing auditory-verbal therapy. A retrospective investigation, the study applied a linear growth model to estimate a mean growth curve and the extent of individual variation in language performance on the Preschool Language Scale, 4th ed.…

  5. Periosteal PTHrP regulates cortical bone modeling during linear growth in mice.

    Science.gov (United States)

    Wang, Meina; VanHouten, Joshua N; Nasiri, Ali R; Tommasini, Steven M; Broadus, Arthur E

    2014-07-01

    The modeling of long bone surfaces during linear growth is a key developmental process, but its regulation is poorly understood. We report here that parathyroid hormone-related peptide (PTHrP) expressed in the fibrous layer of the periosteum (PO) drives the osteoclastic (OC) resorption that models the metaphyseal-diaphyseal junction (MDJ) in the proximal tibia and fibula during linear growth. PTHrP was conditionally deleted (cKO) in the PO via Scleraxis gene targeting (Scx-Cre). In the lateral tibia, cKO of PTHrP led to a failure of modeling, such that the normal concave MDJ was replaced by a mound-like deformity. This was accompanied by a failure to induce receptor activator of NF-kB ligand (RANKL) and a 75% reduction in OC number (P ≤ 0.001) on the cortical surface. The MDJ also displayed a curious threefold increase in endocortical osteoblast mineral apposition rate (P ≤ 0.001) and a thickened cortex, suggesting some form of coupling of endocortical bone formation to events on the PO surface. Because it fuses distally, the fibula is modeled only proximally and does so at an extraordinary rate, with an anteromedial cortex in CD-1 mice that was so moth-eaten that a clear PO surface could not be identified. The cKO fibula displayed a remarkable phenotype, with a misshapen club-like metaphysis and an enlargement in the 3D size of the entire bone, manifest as a 40-45% increase in the PO circumference at the MDJ (P ≤ 0.001) as well as the mid-diaphysis (P ≤ 0.001). These tibial and fibular phenotypes were reproduced in a Scx-Cre-driven RANKL cKO mouse. We conclude that PTHrP in the fibrous PO mediates the modeling of the MDJ of long bones during linear growth, and that in a highly susceptible system such as the fibula this surface modeling defines the size and shape of the entire bone. © 2014 Anatomical Society.

  6. Accretion of fat-free mass rather than fat mass in infancy is positively associated with linear growth in childhood

    DEFF Research Database (Denmark)

    Admassu Wossen, Bitiya; Ritz, Christian; Wells, Jonathan C K

    2018-01-01

    Background: We have previously shown that fat-free mass (FFM) at birth is associated with height at 2 y of age in Ethiopian children. However, to our knowledge, the relation between changes in body composition during early infancy and later linear growth has not been studied. Objective: This study...... examined the associations of early infancy fat mass (FM) and FFM accretion with linear growth from 1 to 5 y of age in Ethiopian children. Methods: In the infant Anthropometry and Body Composition (iABC) study, a prospective cohort study was carried out in children in Jimma, Ethiopia, followed from birth...... to 5 y of age. FM and FFM were measured ≤6 times from birth to 6 mo by using air-displacement plethysmography. Linear mixed-effects models were used to identify associations between standardized FM and FFM accretion rates during early infancy and linear growth from 1 to 5 y of age. Standardized...

  7. Low temperature diamond growth by linear antenna plasma CVD over large area

    International Nuclear Information System (INIS)

    Izak, Tibor; Babchenko, Oleg; Potocky, Stepan; Kromka, Alexander; Varga, Marian

    2012-01-01

    Recently, there is a great effort to increase the deposition area and decrease the process temperature for diamond growth which will enlarge its applications including use of temperature sensitive substrates. In this work, we report on the large area (20 x 30 cm 2 ) and low temperature (250 C) polycrystalline diamond growth by pulsed linear antenna microwave plasma system. The influence of substrate temperature varied from 250 to 680 C, as controlled by the table heater and/or by microwave power, is studied. It was found that the growth rate, film morphology and diamond to non-diamond phases (sp 3 /sp 2 carbon bonds) are influenced by the growth temperature, as confirmed by SEM and Raman measurements. The surface chemistry and growth processes were studied in terms of activation energies (E a ) calculated from Arrhenius plots. The activation energies of growth processes were very low (1.7 and 7.8 kcal mol -1 ) indicating an energetically favourable growth process from the CO 2 -CH 4 -H 2 gas mixture. In addition, from activation energies two different growth regimes were observed at low and high temperatures, indicating different growth mechanism. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Miniaturized Stretchable and High-Rate Linear Supercapacitors

    Science.gov (United States)

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-07-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g-1 at the discharge current of 1 A g-1.

  9. Breast meat quality of chickens with divergent growth rates and its relation to growth curve parameters

    Directory of Open Access Journals (Sweden)

    P. C. Muth

    2017-11-01

    Full Text Available The effects of the increase of body weight of contemporary broilers during growth on functional meat quality and color characteristics of the chicken breast muscle are controversially debated. Therefore, male chickens (n = 264 of a fast-growing commercial broiler (Ross 308 and two slow-growing experimental meat-type chicken lines were compared at equal age and at similar body weight in order to investigate the effect of growth rate on selected functional breast meat traits and meat color. Additionally, the breast meat characteristics of birds with different growth profiles were compared within lines. When the body weight of commercial broilers reached about 40 to 60 % of their growth potential, they exhibited particularly high ultimate pH values compared with slow-growing lines. The ability of the meat of fast-growing broilers to retain water during cooking was impaired (5 to 16 percentage points increased cooking loss compared to slow-growing lines, which, in contrast to pH, was only marginally affected by body weight and/or age at slaughter. No unfavorable correlations of breast meat quality traits with the growth profile, represented by growth curve parameters derived from the Gompertz–Laird equation, were detected within any of the investigated chicken lines. It is noteworthy that the associations of ultimate pH and cooking loss with maximum growth speed indicate a non-linear relationship. Thus, some of the functional characteristics of breast meat of the fast-growing broiler resembled the white-striping defect described for poultry meat, but the hypothesis that selection on increased growth rates is detrimental for meat quality per se could not be confirmed. In fact, an elevated growth potential in particular, i.e., body weight at maturity, could have some beneficial effects for the water-holding capacity of breast meat, regardless of the genotypic growth rate.

  10. Non-linear self-reinforced growth of tearing modes with multiple rational surfaces

    International Nuclear Information System (INIS)

    Maschke, E.K.; Persson, M.; Dewar, R.L.; Australian National Univ., Canberra, ACT

    1993-06-01

    The non-linear evolution of tearing modes with multiple rational surfaces is discussed. It is demonstrated that, in the presence of small differential rotation, the non-linear growth might be faster than exponential. This growth occurs as the rotation frequencies of the plasma at the different rational surfaces go into equilibrium

  11. The effect of shear flow and the density gradient on the Weibel instability growth rate in the dense plasma

    Science.gov (United States)

    Amininasab, S.; Sadighi-Bonabi, R.; Khodadadi Azadboni, F.

    2018-02-01

    Shear stress effect has been often neglected in calculation of the Weibel instability growth rate in laser-plasma interactions. In the present work, the role of the shear stress in the Weibel instability growth rate in the dense plasma with density gradient is explored. By increasing the density gradient, the shear stress threshold is increasing and the range of the propagation angles of growing modes is limited. Therefore, by increasing steps of the density gradient plasma near the relativistic electron beam-emitting region, the Weibel instability occurs at a higher stress flow. Calculations show that the minimum value of the stress rate threshold for linear polarization is greater than that of circular polarization. The Wiebel instability growth rate for linear polarization is 18.3 times circular polarization. One sees that for increasing stress and density gradient effects, there are smaller maximal growth rates for the range of the propagation angles of growing modes /π 2 propagation angles of growing modes /π 2 < θ m i n < π and /3 π 2 < θ m i n < 2 π in circular polarized plasma.

  12. The non-linear growth of the magnetic Rayleigh-Taylor instability

    Science.gov (United States)

    Carlyle, Jack; Hillier, Andrew

    2017-09-01

    This work examines the effect of the embedded magnetic field strength on the non-linear development of the magnetic Rayleigh-Taylor instability (RTI) (with a field-aligned interface) in an ideal gas close to the incompressible limit in three dimensions. Numerical experiments are conducted in a domain sufficiently large so as to allow the predicted critical modes to develop in a physically realistic manner. The ratio between gravity, which drives the instability in this case (as well as in several of the corresponding observations), and magnetic field strength is taken up to a ratio which accurately reflects that of observed astrophysical plasma, in order to allow comparison between the results of the simulations and the observational data which served as inspiration for this work. This study finds reduced non-linear growth of the rising bubbles of the RTI for stronger magnetic fields, and that this is directly due to the change in magnetic field strength, rather than the indirect effect of altering characteristic length scales with respect to domain size. By examining the growth of the falling spikes, the growth rate appears to be enhanced for the strongest magnetic field strengths, suggesting that rather than affecting the development of the system as a whole, increased magnetic field strengths in fact introduce an asymmetry to the system. Further investigation of this effect also revealed that the greater this asymmetry, the less efficiently the gravitational energy is released. By better understanding the under-studied regime of such a major phenomenon in astrophysics, deeper explanations for observations may be sought, and this work illustrates that the strength of magnetic fields in astrophysical plasmas influences observed RTI in subtle and complex ways.

  13. Rate-dependent mode I interlaminar crack growth mechanisms in graphite/epoxy and graphite/PEEK

    Science.gov (United States)

    Gillespie, J. W., Jr.; Carlsson, L. A.; Smiley, A. J.

    1987-01-01

    In this paper the mode I fracture behavior of graphite/epoxy and graphite/PEEK composites is examined over four decades of crosshead rates (0.25-250 mm/min). Straight-sided double-cantilever-beam specimens consisting of unidirectional laminates were tested at room temperature. For graphite/epoxy the load-deflection response was linear to fracture, and stable slow crack growth initiating at the highest load level was observed for all rates tested. In contrast, mode I crack growth in the graphite/PEEK material was often unstable and showed stick-slip behavior. Subcritical crack growth occurring prior to the onset of fracture was observed at intermediate displacement rates. A mechanism for the fracture behavior of the graphite/PEEK material (based on viscoelastic, plastic, and microcrack coalescence in the process zone) is proposed and related to the observed rate-dependent phenomena.

  14. Miniaturized Stretchable and High-Rate Linear Supercapacitors.

    Science.gov (United States)

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-12-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g -1 at the discharge current of 1 A g -1 .

  15. Investigation of the growth rate for joint fast breeder reactor and light water reactor operation

    International Nuclear Information System (INIS)

    Hanan, N.A.; Borg, C.R.; Ott, K.O.

    1977-07-01

    An investigation of fuel consumption and breeding characteristics of FBR-LWR joint operation is presented. The FBR operates in a closed cycle with joint-reprocessing of core and blanket material. The LWR-portion that runs on FBR plutonium operates in an open cycle. The growth rate of the system is defined based upon the fact that the discharge from the system will make up a fraction of an identical system; the system growth rate is found to have an almost linear dependence on the fraction of the LWR fed by plutonium from the FBR. The LWR growth rate, which is negative, is a constant and represents the fraction of the fuel burnt in the LWR-fraction that runs on FBR plutonium per year

  16. On Decidable Growth-Rate Properties of Imperative Programs

    Directory of Open Access Journals (Sweden)

    Amir M. Ben-Amram

    2010-05-01

    Full Text Available In 2008, Ben-Amram, Jones and Kristiansen showed that for a simple "core" programming language - an imperative language with bounded loops, and arithmetics limited to addition and multiplication - it was possible to decide precisely whether a program had certain growth-rate properties, namely polynomial (or linear bounds on computed values, or on the running time. This work emphasized the role of the core language in mitigating the notorious undecidability of program properties, so that one deals with decidable problems. A natural and intriguing problem was whether more elements can be added to the core language, improving its utility, while keeping the growth-rate properties decidable. In particular, the method presented could not handle a command that resets a variable to zero. This paper shows how to handle resets. The analysis is given in a logical style (proof rules, and its complexity is shown to be PSPACE-complete (in contrast, without resets, the problem was PTIME. The analysis algorithm evolved from the previous solution in an interesting way: focus was shifted from proving a bound to disproving it, and the algorithm works top-down rather than bottom-up.

  17. Linear growth of children on a ketogenic diet: does the protein-to-energy ratio matter?

    Science.gov (United States)

    Nation, Judy; Humphrey, Maureen; MacKay, Mark; Boneh, Avihu

    2014-11-01

    Ketogenic diet is a structured effective treatment for children with intractable epilepsy. Several reports have indicated poor linear growth in children on the diet but the mechanism of poor growth has not been elucidated. We aimed to explore whether the protein to energy ratio plays a role in linear growth of children on ketogenic diet. Data regarding growth and nutrition were, retrospectively, collected from the clinical histories of 35 children who were treated with ketogenic diet for at least 6 months between 2002 and 2010. Patients were stratified into groups according to periods of satisfactory or poor linear growth. Poor linear growth was associated with protein or caloric intake of <80% recommended daily intake, and with a protein-to-energy ratio consistently ≤1.4 g protein/100 kcal even when protein and caloric intakes were adequate. We recommend a protein-to-energy ratio of 1.5 g protein/100 kcal be prescribed to prevent growth retardation. © The Author(s) 2013.

  18. Control of the graphene growth rate on capped SiC surface under strong Si confinement

    International Nuclear Information System (INIS)

    Çelebi, C.; Yanık, C.; Demirkol, A.G.; Kaya, İsmet İ.

    2013-01-01

    Highlights: ► Graphene is grown on capped SiC surface with well defined cavity size. ► Graphene growth rate linearly increases with the cavity height. ► Graphene uniformity is reduced with thickness. - Abstract: The effect of the degree of Si confinement on the thickness and morphology of UHV grown epitaxial graphene on (0 0 0 −1) SiC is investigated by using atomic force microscopy and Raman spectroscopy measurements. Prior to the graphene growth process, the C-face surface of a SiC substrate is capped by another SiC comprising three cavities on its Si-rich surface with depths varying from 0.5 to 2 microns. The Si atoms, thermally decomposed from the sample surface during high temperature annealing of the SiC cap /SiC sample stack, are separately trapped inside these individual cavities at the sample/cap interface. Our analyses show that the growth rate linearly increases with the cavity height. It was also found that stronger Si confinement yields more uniform graphene layers.

  19. Dose Rate Effects in Linear Bipolar Transistors

    Science.gov (United States)

    Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

    2011-01-01

    Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

  20. Growth rates and energy intake of hand-reared cheetah cubs (Acinonyx jubatus) in South Africa.

    Science.gov (United States)

    Bell, K M; Rutherfurd, S M; Morton, R H

    2012-04-01

    Growth rate is an important factor in neonatal survival. The aim of this study was to determine growth rates in hand-reared cheetah cubs in South Africa fed a prescribed energy intake, calculated for growth in the domestic cat. Growth was then compared with previously published data from hand-reared cubs in North America and the relationship between growth and energy intake explored. Daily body weight (BW) gain, feed and energy intake data was collected from 18 hand-reared cheetah cubs up to 120 days of age. The average pre-weaning growth rate was 32 g/day, which is lower than reported in mother-reared cubs and hand-reared cubs in North American facilities. However, post-weaning growth increased to an average of 55 g/day. Growth was approximately linear prior to weaning, but over the entire age range it exhibited a sigmoidal shape with an asymptotic plateau averaging 57 kg. Energy intake associated with pre-weaning growth was 481 kJ ME/kg BW(0.75). Regression analysis described the relationship between metabolic BW, metabolisable energy (ME) intake, and hence daily weight gain. This relationship may be useful in predicting energy intake required to achieve growth rates in hand-reared cheetah cubs similar to those observed for their mother-reared counterparts. © 2011 Blackwell Verlag GmbH.

  1. Hoof Growth Rates of the European Roe Deer (Capreolus capreolus for Dating the Hoof’s Isotopic Archive

    Directory of Open Access Journals (Sweden)

    Benjamin D. Hafner

    2017-11-01

    Full Text Available Hooves preserve the isotopic information laid down during their growth and may be used for reconstruction of animal feeding history. To assign certain positions along hooves to corresponding times, growth rates are required. Hoof growth rates are known for domestic animals; however, they cannot be obtained easily in wild animals. We estimated the hoof growth rate of the European roe deer (Capreolus capreolus L. by using the immediate drop in δ13C along the hoof as a tag that is assigned to the date of maize (Zea mays L. harvest. Keratin samples were taken each mm along 17 hooves and analyzed for their δ13C. A linear regression between (1 time differences of expected maize harvest to animal death and (2 distances between the points of the δ13C drop to the periople yielded the growth rate. Mean hoof growth rate was 0.122 mm/day (95% CI 0.014 mm/day and 0.365%/day (±0.026%/day of the hoof length and within the range of domestic animals. The method may be applied to determine growth rates of other incrementally growing tissues. Our estimated growth rate fosters dating isotopic information in hooves, facilitating research on feed resources and space use of roe deer.

  2. The Effect of Exchange Rate and Inflation on Foreign Direct Investment and Its Relationship with Economic Growth in Nigeria

    Directory of Open Access Journals (Sweden)

    Alex Ehimare OMANKHANLEN

    2011-03-01

    Full Text Available This study is on the effect of exchange rate and inflation on foreign direct investment and its relationship with economic growth. Its main objective is to find the effect of inflation and exchange rate and the bidirectional influences between FDI and economic growth in Nigeria. A thirty year period was studied. A linear regression analysis was used on the thirty year data to determine the relationship between inflation, exchange rate, FDI inflows and economic growth. The study reveals that FDI follow economic growth occasioned by trade openness which saw the entry of some major companies especially the telecommunication companies, while Inflation has no effect on FDI. However exchange rate has effect on FDI.

  3. On Associative Conformal Algebras of Linear Growth

    OpenAIRE

    Retakh, Alexander

    2000-01-01

    Lie conformal algebras appear in the theory of vertex algebras. Their relation is similar to that of Lie algebras and their universal enveloping algebras. Associative conformal algebras play a role in conformal representation theory. We introduce the notions of conformal identity and unital associative conformal algebras and classify finitely generated simple unital associative conformal algebras of linear growth. These are precisely the complete algebras of conformal endomorphisms of finite ...

  4. Direct and Maternal Additive Effects on Rabbit Growth and Linear ...

    African Journals Online (AJOL)

    Growth and linear body measurements of rabbits which consisted of 17 ew Zealand White (ZW), 19 Chinchilla (CH), 29 ZW x CH and 33 CH x ZW kittens were compared. The aim of the experiment was to evaluate the crossbreeding effects (i.e direct and maternal additive effect) for growth (individual body weight, IBW) and ...

  5. Newborn length predicts early infant linear growth retardation and disproportionately high weight gain in a low-income population.

    Science.gov (United States)

    Berngard, Samuel Clark; Berngard, Jennifer Bishop; Krebs, Nancy F; Garcés, Ana; Miller, Leland V; Westcott, Jamie; Wright, Linda L; Kindem, Mark; Hambidge, K Michael

    2013-12-01

    Stunting is prevalent by the age of 6 months in the indigenous population of the Western Highlands of Guatemala. The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy. One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 months. Maternal measurements were also obtained. Mean ± SD length-for-age Z-score (LAZ) declined from newborn -1.0 ± 1.01 to -2.20 ± 1.05 and -2.26 ± 1.01 at 3 and 6 months respectively. Stunting rates for newborn, 3 and 6 months were 47%, 53% and 56% respectively. A multiple regression model (R(2) = 0.64) demonstrated that the major predictor of LAZ at 3 months was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education∗maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from -0.44 to +1.28 from birth to 3 months. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ. The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions. © 2013.

  6. Major Changes in Growth Rate and Growth Variability of Beech (Fagus sylvatica L. Related to Soil Alteration and Climate Change in Belgium

    Directory of Open Access Journals (Sweden)

    Nicolas Latte

    2016-08-01

    Full Text Available Global change—particularly climate change, forest management, and atmospheric deposition—has significantly altered forest growing conditions in Europe. The influences of these changes on beech growth (Fagus sylvatica L. were investigated for the past 80 years in Belgium, using non-linear mixed effects models on ring-width chronologies of 149 mature and dominant beech trees (87–186 years old. The effects of the developmental stage (i.e., increasing tree size were filtered out in order to focus on time-dependent growth changes. Beech radial growth was divided into a low-frequency signal (=growth rate, mainly influenced by forest management and atmospheric deposition, and into a high-frequency variability (≈mean sensitivity, mainly influenced by climate change. Between 1930 and 2008, major long-term and time-dependent changes were highlighted. The beech growth rate has decreased by about 38% since the 1950–1960s, and growth variability has increased by about 45% since the 1970–1980s. Our results indicate that (1 before the 1980s, beech growth rate was not predominantly impacted by climate change but rather by soil alteration (i.e., soil compaction and/or nitrogen deposition; and (2 since the 1980s, climate change induced more frequent and intense yearly growth reductions that amplified the growth rate decrease. The highlighted changes were similar in the two ecoregions of Belgium, although more pronounced in the lowlands than in the uplands.

  7. The VIMOS Public Extragalactic Redshift Survey. Measuring the growth rate of structure around cosmic voids

    Science.gov (United States)

    Hawken, A. J.; Granett, B. R.; Iovino, A.; Guzzo, L.; Peacock, J. A.; de la Torre, S.; Garilli, B.; Bolzonella, M.; Scodeggio, M.; Abbas, U.; Adami, C.; Bottini, D.; Cappi, A.; Cucciati, O.; Davidzon, I.; Fritz, A.; Franzetti, P.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Arnouts, S.; Bel, J.; Branchini, E.; De Lucia, G.; Ilbert, O.; Moscardini, L.; Percival, W. J.

    2017-11-01

    We aim to develop a novel methodology for measuring thegrowth rate of structure around cosmic voids. We identified voids in the completed VIMOS Public Extragalactic Redshift Survey (VIPERS), using an algorithm based on searching for empty spheres. We measured the cross-correlation between the centres of voids and the complete galaxy catalogue. The cross-correlation function exhibits a clear anisotropy in both VIPERS fields (W1 and W4), which is characteristic of linear redshift space distortions. By measuring the projected cross-correlation and then de-projecting it we are able to estimate the un-distorted cross-correlation function. We propose that given a sufficiently well-measured cross-correlation function one should be able to measure the linear growth rate of structure by applying a simple linear Gaussian streaming model for the redshift space distortions (RSD). Our study of voids in 306 mock galaxy catalogues mimicking the VIPERS fields suggests that VIPERS is capable of measuring β, the ratio of the linear growth rate to the bias, with an error of around 25%. Applying our method to the VIPERS data, we find a value for the redshift space distortion parameter, β = 0.423-0.108+0.104 which, given the bias of the galaxy population we use, gives a linear growth rate of f σ8 = 0.296-0.078+0.075 at z = 0.727. These results are consistent with values observed in parallel VIPERS analyses that use standard techniques. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programs 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in

  8. Sodium flow rate measurement method of annular linear induction pump

    International Nuclear Information System (INIS)

    Araseki, Hideo

    2011-01-01

    This report describes a method for measuring sodium flow rate of annular linear induction pumps arranged in parallel and its verification result obtained through an experiment and a numerical analysis. In the method, the leaked magnetic field is measured with measuring coils at the stator end on the outlet side and is correlated with the sodium flow rate. The experimental data and the numerical result indicate that the leaked magnetic field at the stator edge keeps almost constant when the sodium flow rate changes and that the leaked magnetic field change arising from the flow rate change is small compared with the overall leaked magnetic field. It is shown that the correlation between the leaked magnetic field and the sodium flow rate is almost linear due to this feature of the leaked magnetic field, which indicates the applicability of the method to small-scale annular linear induction pumps. (author)

  9. Non-linear direct effects of acid rain on leaf photosynthetic rate of terrestrial plants.

    Science.gov (United States)

    Dong, Dan; Du, Enzai; Sun, Zhengzhong; Zeng, Xuetong; de Vries, Wim

    2017-12-01

    Anthropogenic emissions of acid precursors have enhanced global occurrence of acid rain, especially in East Asia. Acid rain directly suppresses leaf function by eroding surface waxes and cuticle and leaching base cations from mesophyll cells, while the simultaneous foliar uptake of nitrates in rainwater may directly benefit leaf photosynthesis and plant growth, suggesting a non-linear direct effect of acid rain. By synthesizing data from literature on acid rain exposure experiments, we assessed the direct effects of acid rain on leaf photosynthesis across 49 terrestrial plants in China. Our results show a non-linear direct effect of acid rain on leaf photosynthetic rate, including a neutral to positive effect above pH 5.0 and a negative effect below that pH level. The acid rain sensitivity of leaf photosynthesis showed no significant difference between herbs and woody species below pH 5.0, but the impacts above that pH level were strongly different, resulting in a significant increase in leaf photosynthetic rate of woody species and an insignificant effect on herbs. Our analysis also indicates a positive effect of the molar ratio of nitric versus sulfuric acid in the acid solution on leaf photosynthetic rate. These findings imply that rainwater acidity and the composition of acids both affect the response of leaf photosynthesis and therefore result in a non-linear direct effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Linear rate-equilibrium relations arising from ion channel-bilayer energetic coupling

    DEFF Research Database (Denmark)

    Greisen, Per Junior; Lum, Kevin; Ashrafuzzaman, Md

    2011-01-01

    Linear rate-equilibrium (RE) relations, also known as linear free energy relations, are widely observed in chemical reactions, including protein folding, enzymatic catalysis, and channel gating. Despite the widespread occurrence of linear RE relations, the principles underlying the linear relatio...

  11. Linear analysis on the growth of non-spherical perturbations in supersonic accretion flows

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Kazuya; Yamada, Shoichi, E-mail: ktakahashi@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku 169-8555 (Japan)

    2014-10-20

    We analyzed the growth of non-spherical perturbations in supersonic accretion flows. We have in mind an application to the post-bounce phase of core-collapse supernovae (CCSNe). Such non-spherical perturbations have been suggested by a series of papers by Arnett, who has numerically investigated violent convections in the outer layers of pre-collapse stars. Moreover, Couch and Ott demonstrated in their numerical simulations that such perturbations may lead to a successful supernova even for a progenitor that fails to explode without fluctuations. This study investigated the linear growth of perturbations during the infall onto a stalled shock wave. The linearized equations are solved as an initial and boundary value problem with the use of a Laplace transform. The background is a Bondi accretion flow whose parameters are chosen to mimic the 15 M {sub ☉} progenitor model by Woosley and Heger, which is supposed to be a typical progenitor of CCSNe. We found that the perturbations that are given at a large radius grow as they flow down to the shock radius; the density perturbations can be amplified by a factor of 30, for example. We analytically show that the growth rate is proportional to l, the index of the spherical harmonics. We also found that the perturbations oscillate in time with frequencies that are similar to those of the standing accretion shock instability. This may have an implication for shock revival in CCSNe, which will be investigated in our forthcoming paper in more detail.

  12. Short- and long-term variations in non-linear dynamics of heart rate variability

    DEFF Research Database (Denmark)

    Kanters, J K; Højgaard, M V; Agner, E

    1996-01-01

    OBJECTIVES: The purpose of the study was to investigate the short- and long-term variations in the non-linear dynamics of heart rate variability, and to determine the relationships between conventional time and frequency domain methods and the newer non-linear methods of characterizing heart rate...... rate and describes mainly linear correlations. Non-linear predictability is correlated with heart rate variability measured as the standard deviation of the R-R intervals and the respiratory activity expressed as power of the high-frequency band. The dynamics of heart rate variability changes suddenly...

  13. Sex-based differences in Adelie penguin (Pygoscelis adeliae) chick growth rates.

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Catherine; Ballard, Grant; Ainley, David G.

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species—one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact

  14. Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

    DEFF Research Database (Denmark)

    Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus

    2009-01-01

    , quantified as time to first feeding, and growth in later stages was demonstrated in Atlantic salmon (Salmo salar L.). The observed relationship between future growth and larval developmental rate suggests that sorting larvae by time to first feeding can be a potential tool to optimize feeding strategies...... and growth in commercial rearing of Atlantic salmon. Furthermore, the link between larval standard metabolic rate and developmental rate and future growth is discussed in the present study....

  15. The relationships among iron supplement use, Hb concentration and linear growth in young children: Ethiopian Demographic and Health Survey.

    Science.gov (United States)

    Mohammed, Shimels Hussien; Esmaillzadeh, Ahmad

    2017-11-01

    Growth faltering and anaemia remain unacceptably high among infants and young children in Ethiopia. In this study, we investigated the relationships among Fe supplement use (ISU), Hb concentration and linear growth, hypothesising positive relationships between ISU and Hb, ISU and linear growth and Hb and linear growth. We used a nationally representative data of 2400 children aged 6-24 months from the Ethiopian Demographic and Health Survey (EDHS) 2011, conducted following a stratified, two-stage cluster sampling. We examined the links by Pearson's correlation, bivariate and multivariate linear regression analyses and reported adjusted estimates. We found that ISU was not significantly associated with either Hb (β=1·09; 95 % CI -2·73, 5·01, P=0·567) or linear growth (β=0·07; 95 % CI -0·06, 0·21, P=0·217). We found a positive, however, weak, correlation between Hb and linear growth (r 0·09; 95 % CI 0·06, 0·11, PHb predicted linear growth independent of a variety dietary and non-dietary factors (β=0·08; 95 % CI 0·04, 0·11, PHb; age, birth type, size at birth, sex, breast-feeding duration, dietary diversity and deworming were independently associated with linear growth, indicating that Hb and linear growth are multifactorial with both nutritional and non-nutritional factors implicated. Further studies, with better design and exposure assessment, are warranted on the relation of ISU with Hb or linear growth.

  16. Connection between the growth rate distribution and the size dependent crystal growth

    Science.gov (United States)

    Mitrović, M. M.; Žekić, A. A.; IIić, Z. Z.

    2002-07-01

    The results of investigations of the connection between the growth rate dispersions and the size dependent crystal growth of potassium dihydrogen phosphate (KDP), Rochelle salt (RS) and sodium chlorate (SC) are presented. A possible way out of the existing confusion in the size dependent crystal growth investigations is suggested. It is shown that the size independent growth exists if the crystals belonging to one growth rate distribution maximum are considered separately. The investigations suggest possible reason for the observed distribution maxima widths, and the high data scattering on the growth rate versus the crystal size dependence.

  17. Standard test method for measurement of fatigue crack growth rates

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    1.1 This test method covers the determination of fatigue crack growth rates from near-threshold to Kmax controlled instability. Results are expressed in terms of the crack-tip stress-intensity factor range (ΔK), defined by the theory of linear elasticity. 1.2 Several different test procedures are provided, the optimum test procedure being primarily dependent on the magnitude of the fatigue crack growth rate to be measured. 1.3 Materials that can be tested by this test method are not limited by thickness or by strength so long as specimens are of sufficient thickness to preclude buckling and of sufficient planar size to remain predominantly elastic during testing. 1.4 A range of specimen sizes with proportional planar dimensions is provided, but size is variable to be adjusted for yield strength and applied force. Specimen thickness may be varied independent of planar size. 1.5 The details of the various specimens and test configurations are shown in Annex A1-Annex A3. Specimen configurations other than t...

  18. Sodium flow rate measurement method of annular linear induction pumps

    International Nuclear Information System (INIS)

    Araseki, Hideo; Kirillov, Igor R.; Preslitsky, Gennady V.

    2012-01-01

    Highlights: ► We found a new method of flow rate monitoring of electromagnetic pump. ► The method is very simple and does not require a large space. ► The method was verified with an experiment and a numerical analysis. ► The experimental data and the numerical results are in good agreement. - Abstract: The present paper proposes a method for measuring sodium flow rate of annular linear induction pumps. The feature of the method lies in measuring the leaked magnetic field with measuring coils near the stator end on the outlet side and in correlating it with the sodium flow rate. This method is verified through an experiment and a numerical analysis. The data obtained in the experiment reveals that the correlation between the leaked magnetic field and the sodium flow rate is almost linear. The result of the numerical analysis agrees with the experimental data. The present method will be particularly effective to sodium flow rate monitoring of each one of plural annular linear induction pumps arranged in parallel in a vessel which forms a large-scale pump unit.

  19. Measurement of the volume growth rate of single budding yeast with the MOSFET-based microfluidic Coulter counter.

    Science.gov (United States)

    Sun, Jiashu; Stowers, Chris C; Boczko, Erik M; Li, Deyu

    2010-11-07

    We report on measurements of the volume growth rate of ten individual budding yeast cells using a recently developed MOSFET-based microfluidic Coulter counter. The MOSFET-based microfluidic Coulter counter is very sensitive, provides signals that are immune from the baseline drift, and can work with cell culture media of complex composition. These desirable features allow us to directly measure the volume growth rate of single cells of Saccharomyces cerevisiae LYH3865 strain budding yeast in YNB culture media over a whole cell cycle. Results indicate that all budding yeast follow a sigmoid volume growth profile with reduced growth rates at the initial stage before the bud emerges and the final stage after the daughter gets mature. Analysis of the data indicates that even though all piecewise linear, Gomperitz, and Hill's function models can fit the global growth profile equally well, the data strongly support local exponential growth phenomenon. Accurate volume growth measurements are important for applications in systems biology where quantitative parameters are required for modeling and simulation.

  20. Growth Rates of Microbes in the Oceans.

    Science.gov (United States)

    Kirchman, David L

    2016-01-01

    A microbe's growth rate helps to set its ecological success and its contribution to food web dynamics and biogeochemical processes. Growth rates at the community level are constrained by biomass and trophic interactions among bacteria, phytoplankton, and their grazers. Phytoplankton growth rates are approximately 1 d(-1), whereas most heterotrophic bacteria grow slowly, close to 0.1 d(-1); only a few taxa can grow ten times as fast. Data from 16S rRNA and other approaches are used to speculate about the growth rate and the life history strategy of SAR11, the most abundant clade of heterotrophic bacteria in the oceans. These strategies are also explored using genomic data. Although the methods and data are imperfect, the available data can be used to set limits on growth rates and thus on the timescale for changes in the composition and structure of microbial communities.

  1. Investigation of various growth mechanisms of solid tumour growth within the linear-quadratic model for radiotherapy

    International Nuclear Information System (INIS)

    McAneney, H; O'Rourke, S F C

    2007-01-01

    The standard linear-quadratic survival model for radiotherapy is used to investigate different schedules of radiation treatment planning to study how these may be affected by different tumour repopulation kinetics between treatments. The laws for tumour cell repopulation include the logistic and Gompertz models and this extends the work of Wheldon et al (1977 Br. J. Radiol. 50 681), which was concerned with the case of exponential re-growth between treatments. Here we also consider the restricted exponential model. This has been successfully used by Panetta and Adam (1995 Math. Comput. Modelling 22 67) in the case of chemotherapy treatment planning.Treatment schedules investigated include standard fractionation of daily treatments, weekday treatments, accelerated fractionation, optimized uniform schedules and variation of the dosage and α/β ratio, where α and β are radiobiological parameters for the tumour tissue concerned. Parameters for these treatment strategies are extracted from the literature on advanced head and neck cancer, prostate cancer, as well as radiosensitive parameters. Standardized treatment protocols are also considered. Calculations based on the present analysis indicate that even with growth laws scaled to mimic initial growth, such that growth mechanisms are comparable, variation in survival fraction to orders of magnitude emerged. Calculations show that the logistic and exponential models yield similar results in tumour eradication. By comparison the Gompertz model calculations indicate that tumours described by this law result in a significantly poorer prognosis for tumour eradication than either the exponential or logistic models. The present study also shows that the faster the tumour growth rate and the higher the repair capacity of the cell line, the greater the variation in outcome of the survival fraction. Gaps in treatment, planned or unplanned, also accentuate the differences of the survival fraction given alternative growth

  2. The effect of zinc supplementation on linear growth, body composition, and growth factors in preterm infants.

    Science.gov (United States)

    Díaz-Gómez, N Marta; Doménech, Eduardo; Barroso, Flora; Castells, Silvia; Cortabarria, Carmen; Jiménez, Alejandro

    2003-05-01

    The aim of our study was to evaluate the effect of zinc supplementation on linear growth, body composition, and growth factors in premature infants. Thirty-six preterm infants (gestational age: 32.0 +/- 2.1 weeks, birth weight: 1704 +/- 364 g) participated in a longitudinal double-blind, randomized clinical trial. They were randomly allocated either to the supplemental (S) group fed with a standard term formula supplemented with zinc (final content 10 mg/L) and a small quantity of copper (final content 0.6 mg/L), or to the placebo group fed with the same formula without supplementation (final content of zinc: 5 mg/L and copper: 0.4 mg/L), from 36 weeks postconceptional age until 6 months corrected postnatal age. At each evaluation, anthropometric variables and bioelectrical impedance were measured, a 3-day dietary record was collected, and a blood sample was taken. We analyzed serum levels of total alkaline phosphatase, skeletal alkaline phosphatase (sALP), insulin growth factor (IGF)-I, IGF binding protein-3, IGF binding protein-1, zinc and copper, and the concentrations of zinc in erythrocytes. The S group had significantly higher zinc levels in serum and erythrocytes and lower serum copper levels with respect to the placebo group. We found that the S group had a greater linear growth (from baseline to 3 months corrected age: Delta score deviation standard length: 1.32 +/-.8 vs.38 +/-.8). The increase in total body water and in serum levels of sALP was also significantly higher in the S group (total body water: 3 months; corrected age: 3.8 +/-.5 vs 3.5 +/-.4 kg, 6 months; corrected age: 4.5 +/-.5 vs 4.2 +/-.4 kg; sALP: 3 months; corrected age: 140.2 +/- 28.7 vs 118.7 +/- 18.8 micro g/L). Zinc supplementation has a positive effect on linear growth in premature infants.

  3. Effect of massing on larval growth rate.

    Science.gov (United States)

    Johnson, Aidan P; Wallman, James F

    2014-08-01

    Estimation of minimum postmortem interval commonly relies on predicting the age of blowfly larvae based on their size and an estimate of the temperatures to which they have been exposed throughout their development. The majority of larval growth rate data have been developed using small larval masses in order to avoid excess heat generation. The current study collected growth rate data for larvae at different mass volumes, and assessed the temperature production of these masses, for two forensically important blow fly species, Chrysomya rufifacies and Calliphora vicina. The growth rate of larvae in a small mass, exposed to the higher temperatures equivalent to those experienced by large masses, was also assessed to determine if observed differences were due to the known temperature effects of maggot masses. The results showed that temperature production increased with increasing mass volume, with temperature increases of 11 °C observed in the large Ch. rufifacies masses and increases of 5 °C in the large C. vicina masses. Similarly, the growth rate of the larvae was affected by mass size. The larvae from small masses grown at the higher temperatures experienced by large masses displayed an initial delay in growth, but then grew at a similar rate to those larvae at a constant 23 °C. Since these larvae from masses of equivalent sizes displayed similar patterns of growth rate, despite differing temperatures, and these growth rates differed from larger masses exposed to the same temperatures, it can be concluded that larval growth rate within a mass may be affected by additional factors other than temperature. Overall, this study highlights the importance of understanding the role of massing in larval development and provides initial developmental data for mass sizes of two forensically important blowfly species commonly encountered in Australian forensic casework. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Plant allometry, leaf nitrogen and phosphorus stoichiometry, and interspecific trends in annual growth rates.

    Science.gov (United States)

    Niklas, Karl J

    2006-02-01

    Life forms as diverse as unicellular algae, zooplankton, vascular plants, and mammals appear to obey quarter-power scaling rules. Among the most famous of these rules is Kleiber's (i.e. basal metabolic rates scale as the three-quarters power of body mass), which has a botanical analogue (i.e. annual plant growth rates scale as the three-quarters power of total body mass). Numerous theories have tried to explain why these rules exist, but each has been heavily criticized either on conceptual or empirical grounds. N,P-STOICHIOMETRY: Recent models predicting growth rates on the basis of how total cell, tissue, or organism nitrogen and phosphorus are allocated, respectively, to protein and rRNA contents may provide the answer, particularly in light of the observation that annual plant growth rates scale linearly with respect to standing leaf mass and that total leaf mass scales isometrically with respect to nitrogen but as the three-quarters power of leaf phosphorus. For example, when these relationships are juxtaposed with other allometric trends, a simple N,P-stoichiometric model successfully predicts the relative growth rates of 131 diverse C3 and C4 species. The melding of allometric and N,P-stoichiometric theoretical insights provides a robust modelling approach that conceptually links the subcellular 'machinery' of protein/ribosomal metabolism to observed growth rates of uni- and multicellular organisms. Because the operation of this 'machinery' is basic to the biology of all life forms, its allometry may provide a mechanistic explanation for the apparent ubiquity of quarter-power scaling rules.

  5. Linear neoclassical tearing mode in tokamaks

    International Nuclear Information System (INIS)

    Shaing, K. C.

    2007-01-01

    The growth rate of linear tearing modes in tokamaks is calculated including the neoclassical dissipation mechanism. It is found that when the growth rate is much smaller than the ion-ion collision frequency, the growth rate is reduced approximately by a factor of (B p /B) 2/5 from its standard value, and when the growth rate is much larger than the ion-ion collision frequency, the growth rate is reduced by a factor [√(ε)/(1.6q 2 )] 1/5 . Here, B p is the poloidal magnetic field strength, B is the magnetic field strength, ε is the inverse aspect ratio, and q is the safety factor. The width of the resistive layer is broadened when compared to that of the standard theory. In both limits, the growth rate and the resistive layer width only depend on B p and are independent of B. The growth rates in the plateau regime and for the inertia dominant modes are also presented

  6. Growth rate of Heterobasidion annosum in Picea abies established on forest land and arable land

    Energy Technology Data Exchange (ETDEWEB)

    Bendz-Hellgren, M.; Johansson, Martin; Swedjemark, G.; Stenlid, J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology; Brandtberg, P.O. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    1999-07-01

    The growth rates of Heterobasidion annosum in Norway spruce were investigated in southern Sweden. In one study, stump and tree roots in stands established on previous forest or arable land were inoculated with H. annosum-infested sawdust. After 1-3 yrs, the linear extent of colonization by the fungus was measured, based on detection of its conidiophores on incubated samples. The average growth rate was 25 cm yr{sup -1} in stump roots and 9 cm yr{sup -1} in tree roots, neither of which differed significantly between forest and arable land. The feeling of a decayed tree could enhance the spread of H. annosum within root systems. In the second study, the height of discoloration and extent of colonization by H. annosum, measured as above, were assessed in naturally infected trees. On average, discoloration moved through the roots and stem at a rate of 36 cm yr{sup -1}. Heterobasidion annosum was found 60 cm in advance of the discoloration, corresponding to a growth rate of 52 cm yr{sup -1}.

  7. Modelling subject-specific childhood growth using linear mixed-effect models with cubic regression splines.

    Science.gov (United States)

    Grajeda, Laura M; Ivanescu, Andrada; Saito, Mayuko; Crainiceanu, Ciprian; Jaganath, Devan; Gilman, Robert H; Crabtree, Jean E; Kelleher, Dermott; Cabrera, Lilia; Cama, Vitaliano; Checkley, William

    2016-01-01

    Childhood growth is a cornerstone of pediatric research. Statistical models need to consider individual trajectories to adequately describe growth outcomes. Specifically, well-defined longitudinal models are essential to characterize both population and subject-specific growth. Linear mixed-effect models with cubic regression splines can account for the nonlinearity of growth curves and provide reasonable estimators of population and subject-specific growth, velocity and acceleration. We provide a stepwise approach that builds from simple to complex models, and account for the intrinsic complexity of the data. We start with standard cubic splines regression models and build up to a model that includes subject-specific random intercepts and slopes and residual autocorrelation. We then compared cubic regression splines vis-à-vis linear piecewise splines, and with varying number of knots and positions. Statistical code is provided to ensure reproducibility and improve dissemination of methods. Models are applied to longitudinal height measurements in a cohort of 215 Peruvian children followed from birth until their fourth year of life. Unexplained variability, as measured by the variance of the regression model, was reduced from 7.34 when using ordinary least squares to 0.81 (p linear mixed-effect models with random slopes and a first order continuous autoregressive error term. There was substantial heterogeneity in both the intercept (p modeled with a first order continuous autoregressive error term as evidenced by the variogram of the residuals and by a lack of association among residuals. The final model provides a parametric linear regression equation for both estimation and prediction of population- and individual-level growth in height. We show that cubic regression splines are superior to linear regression splines for the case of a small number of knots in both estimation and prediction with the full linear mixed effect model (AIC 19,352 vs. 19

  8. Effect of milk proteins on linear growth and IGF variables in overweight adolescents

    DEFF Research Database (Denmark)

    Larnkjær, Anni; Arnberg, Karina; Michaelsen, Kim F

    2014-01-01

    Milk may stimulate growth acting via insulin-like growth factor-I (IGF-I) secretion but the effect in adolescents is less examined. This study investigates the effect of milk proteins on linear growth, IGF-I, IGF binding protein-3 (IGFBP-3) and IGF-I/IGFBP-3 ratio in overweight adolescents....

  9. Linear and Non-Linear Associations of Gonorrhea Diagnosis Rates with Social Determinants of Health

    Directory of Open Access Journals (Sweden)

    Hazel D. Dean

    2012-09-01

    Full Text Available Identifying how social determinants of health (SDH influence the burden of disease in communities and populations is critically important to determine how to target public health interventions and move toward health equity. A holistic approach to disease prevention involves understanding the combined effects of individual, social, health system, and environmental determinants on geographic area-based disease burden. Using 2006–2008 gonorrhea surveillance data from the National Notifiable Sexually Transmitted Disease Surveillance and SDH variables from the American Community Survey, we calculated the diagnosis rate for each geographic area and analyzed the associations between those rates and the SDH and demographic variables. The estimated product moment correlation (PMC between gonorrhea rate and SDH variables ranged from 0.11 to 0.83. Proportions of the population that were black, of minority race/ethnicity, and unmarried, were each strongly correlated with gonorrhea diagnosis rates. The population density, female proportion, and proportion below the poverty level were moderately correlated with gonorrhea diagnosis rate. To better understand relationships among SDH, demographic variables, and gonorrhea diagnosis rates, more geographic area-based estimates of additional variables are required. With the availability of more SDH variables and methods that distinguish linear from non-linear associations, geographic area-based analysis of disease incidence and SDH can add value to public health prevention and control programs.

  10. Forecasting the EMU inflation rate: Linear econometric vs. non-linear computational models using genetic neural fuzzy systems

    DEFF Research Database (Denmark)

    Kooths, Stefan; Mitze, Timo Friedel; Ringhut, Eric

    2004-01-01

    This paper compares the predictive power of linear econometric and non-linear computational models for forecasting the inflation rate in the European Monetary Union (EMU). Various models of both types are developed using different monetary and real activity indicators. They are compared according...

  11. GROWTH RATE DISTRIBUTION OF BORAX SINGLE CRYSTALS ON THE (001 FACE UNDER VARIOUS FLOW RATES

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available The growth rates of borax single crystals from aqueous solutions at various flow rates in the (001 direction were measured using in situ cell method. From the growth rate data obtained, the growth rate distribution of borax crystals was investigated using Minitab Software and SPSS Software at relative supersaturation of 0807 and temperature of 25 °C. The result shows that normal, gamma, and log-normal distribution give a reasonably good fit to GRD. However, there is no correlation between growth rate distribution and flow rate of solution.   Keywords: growth rate dispersion (GRD, borax, flow rate

  12. Dinosaur Metabolism and the Allometry of Maximum Growth Rate.

    Science.gov (United States)

    Myhrvold, Nathan P

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued.

  13. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    Science.gov (United States)

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued. PMID:27828977

  14. Morphology and mycelial growth rate of Pleurotus spp. strains from the Mexican mixtec region

    Science.gov (United States)

    Guadarrama-Mendoza, P.C.; del Toro, G. Valencia; Ramírez-Carrillo, R.; Robles-Martínez, F.; Yáñez-Fernández, J.; Garín-Aguilar, M.E.; Hernández, C.G.; Bravo-Villa, G.

    2014-01-01

    Two native Pleurotus spp. strains (white LB-050 and pale pink LB-051) were isolated from rotten tree trunks of cazahuate (Ipomoea murucoides) from the Mexican Mixtec Region. Both strains were chemically dedikaryotized to obtain their symmetrical monokaryotic components (neohaplonts). This was achieved employing homogenization time periods from 60 to 65 s, and 3 day incubation at 28 °C in a peptone-glucose solution (PGS). Pairing of compatible neohaplonts resulted in 56 hybrid strains which were classified into the four following hybrid types: (R1-nxB1-n, R1-nxB2-1, R2-nxB1-n and R2-nxB2-1). The mycelial growth of Pleurotus spp. monokaryotic and dikaryotic strains showed differences in texture (cottony or floccose), growth (scarce, regular or abundant), density (high, regular or low), and pigmentation (off-white, white or pale pink). To determine the rate and the amount of mycelium growth in malt extract agar at 28 °C, the diameter of the colony was measured every 24 h until the Petri dish was completely colonized. A linear model had the best fit to the mycelial growth kinetics. A direct relationship between mycelial morphology and growth rate was observed. Cottony mycelium presented significantly higher growth rates (p < 0.01) in comparison with floccose mycelium. Thus, mycelial morphology can be used as criterion to select which pairs must be used for optimizing compatible-mating studies. Hybrids resulting from cottony neohaplonts maintained the characteristically high growth rates of their parental strains with the hybrid R1-nxB1-n being faster than the latter. PMID:25477920

  15. Microtubules Growth Rate Alteration in Human Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Irina B. Alieva

    2010-01-01

    Full Text Available To understand how microtubules contribute to the dynamic reorganization of the endothelial cell (EC cytoskeleton, we established an EC model expressing EB3-GFP, a protein that marks microtubule plus-ends. Using this model, we were able to measure microtubule growth rate at the centrosome region and near the cell periphery of a single human EC and in the EC monolayer. We demonstrate that the majority of microtubules in EC are dynamic, the growth rate of their plus-ends is highest in the internal cytoplasm, in the region of the centrosome. Growth rate of microtubule plus-ends decreases from the cell center toward the periphery. Our data suggest the existing mechanism(s of local regulation of microtubule plus-ends growth in EC. Microtubule growth rate in the internal cytoplasm of EC in the monolayer is lower than that of single EC suggesting the regulatory effect of cell-cell contacts. Centrosomal microtubule growth rate distribution in single EC indicated the presence of two subpopulations of microtubules with “normal” (similar to those in monolayer EC and “fast” (three times as much growth rates. Our results indicate functional interactions between cell-cell contacts and microtubules.

  16. Local linear heat rate ramps in the WWER-440 transient regimes

    International Nuclear Information System (INIS)

    Brik, A.N.; Bibilashvili, Ju.L.; Bogatyr, S.M.; Medvedev, A.V.

    1998-01-01

    The operation of the WWER-440 reactors must be accomplished in such a way that the fuel rods durability would be high enough during the whole operation period. The important factors determining the absence of fuel rod failures are the criteria limiting the core characteristics (fuel rod and fuel assembly power, local linear heat rate, etc.). For the transient and load follow conditions the limitations on the permissible local linear rate ramp are also introduced. This limitation is the result of design limit of stress corrosion cracking of the fuel cladding and depends on the local fuel burn-up. The control rod motion is accompanied by power redistribution, which, in principle, can result in violating the design and operation limitations. Consequently, this motion have to be such as the core parameters, including the local ramps of the linear heat generation rates would not exceed the permissible ones.The paper considers the problem of WWER-440 reactor control under transient and load follow conditions and the associated optimisation of local linear heat generation rate ramps. The main factors affecting the solution of the problem under consideration are discussed. Some recommendations for a more optimal reactor operation are given.(Author)

  17. Effect of synchronizing the rate of degradation of dietary energy and nitrogen release on growth performance in Brahman cattle

    Directory of Open Access Journals (Sweden)

    Virote Pattarajinda

    2006-01-01

    Full Text Available The objective of this research was to determine the effect of synchronizing the rate of degradation of dietary energy and nitrogen release on growth performance in Brahman beef cattle. Fifteen Brahman cattle, 1.5 years old, with an average initial body weight of 184.8±11.1 kg were assigned to one of three treatments according to a randomized complete block design. Dietary treatments contained 3 levels of synchrony index (0.39, 0.56 and 0.74 that were derived from laboratory chemical composition analysis and degradation kinetics using nylon bag technique. Diets were fed at the rate of 2.5% BW by separate concentrate and roughage. Average daily gain increased linearly (P<0.05 with increase levels of synchrony index in the diets. The digestibility of dry matter, organic matter and neutral detergent fiber increased linearly (P<0.01. The digestibility of acid detergent fiber increased linearly (P<0.05. Ruminal total volatile fatty acids concentration increased linearly (P<0.05 at 6 h post feeding. Higher concentration and fluctuation of ruminal ammonia nitrogen and blood urea nitrogen were observed in animals that received lower synchrony index in their diets. Rumen microbial population tended to increase with diets having higher levels of synchrony index. The results indicated that synchronized rate of dietary energy and nitrogen degradation improved ruminal fermentation and digestibility, thus this increased the growth rate in Brahman cattle fed with ricestraw- based diets.

  18. Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis.

    Science.gov (United States)

    Blair, David P; Blanchard, Wade; Banks, Sam C; Lindenmayer, David B

    2017-01-01

    Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two species were unaffected by aspect and elevation but slope had a minor effect with D. antarctica growing 0.3mm faster for each additional degree of slope. Geographic location influenced growth in both species by up to 12 - 14mm/yr. The most consistent factor influencing growth rate, however, was initial height at the time of the 2009 fire; a finding consistent in both species and all geographic locations. For both tree fern species, individuals that were taller at the commencement of the study had greater overall growth for the duration of the study. This effect did not decrease even among the tallest tree ferns in our study (up to 6 metres tall). Overall, Cyathea australis averaged 73 (± 22)mm/year of growth (± 1SD), with the rate increasing 5mm/yr per metre of additional height. Dicksonia antarctica averaged 33 (± 13)mm/year, increasing by 6mm/yr/m. Growth rates dependent on initial height were unexpected and we discuss possible reasons for this finding. Variable growth rates also suggest that common age estimation methods of dividing height by average growth rate are likely to underestimate the age of short tree ferns, while overestimating the age of tall tree ferns, particularly if they have been subject to a fire.

  19. Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis.

    Directory of Open Access Journals (Sweden)

    David P Blair

    Full Text Available Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two species were unaffected by aspect and elevation but slope had a minor effect with D. antarctica growing 0.3mm faster for each additional degree of slope. Geographic location influenced growth in both species by up to 12 - 14mm/yr. The most consistent factor influencing growth rate, however, was initial height at the time of the 2009 fire; a finding consistent in both species and all geographic locations. For both tree fern species, individuals that were taller at the commencement of the study had greater overall growth for the duration of the study. This effect did not decrease even among the tallest tree ferns in our study (up to 6 metres tall. Overall, Cyathea australis averaged 73 (± 22mm/year of growth (± 1SD, with the rate increasing 5mm/yr per metre of additional height. Dicksonia antarctica averaged 33 (± 13mm/year, increasing by 6mm/yr/m. Growth rates dependent on initial height were unexpected and we discuss possible reasons for this finding. Variable growth rates also suggest that common age estimation methods of dividing height by average growth rate are likely to underestimate the age of short tree ferns, while overestimating the age of tall tree ferns, particularly if they have been subject to a fire.

  20. Exchange-rate regimes and economic growth: An empirical evaluation

    OpenAIRE

    Simón Sosvilla-Rivero; María del Carmen Ramos-Herrera

    2014-01-01

    Based on a dataset of 123 economies, this paper empirically investigates the relation between exchange-rate regimes and economic growth. We find that growth performance is best under intermediate exchange rate regimes, while the smallest growth rates are associated with flexible exchange rates. Nevertheless, this conclusion is tempered when we analyze the countries by income level: even though countries that adopt intermediate exchange-rate regimes are characterized by higher economic growth,...

  1. Model for predicting non-linear crack growth considering load sequence effects (LOSEQ)

    International Nuclear Information System (INIS)

    Fuehring, H.

    1982-01-01

    A new analytical model for predicting non-linear crack growth is presented which takes into account the retardation as well as the acceleration effects due to irregular loading. It considers not only the maximum peak of a load sequence to effect crack growth but also all other loads of the history according to a generalised memory criterion. Comparisons between crack growth predicted by using the LOSEQ-programme and experimentally observed data are presented. (orig.) [de

  2. Non-Linear Relationship between Economic Growth and CO₂ Emissions in China: An Empirical Study Based on Panel Smooth Transition Regression Models.

    Science.gov (United States)

    Wang, Zheng-Xin; Hao, Peng; Yao, Pei-Yi

    2017-12-13

    The non-linear relationship between provincial economic growth and carbon emissions is investigated by using panel smooth transition regression (PSTR) models. The research indicates that, on the condition of separately taking Gross Domestic Product per capita (GDPpc), energy structure (Es), and urbanisation level (Ul) as transition variables, three models all reject the null hypothesis of a linear relationship, i.e., a non-linear relationship exists. The results show that the three models all contain only one transition function but different numbers of location parameters. The model taking GDPpc as the transition variable has two location parameters, while the other two models separately considering Es and Ul as the transition variables both contain one location parameter. The three models applied in the study all favourably describe the non-linear relationship between economic growth and CO₂ emissions in China. It also can be seen that the conversion rate of the influence of Ul on per capita CO₂ emissions is significantly higher than those of GDPpc and Es on per capita CO₂ emissions.

  3. Linear ubiquitin chain induces apoptosis and inhibits tumor growth.

    Science.gov (United States)

    Qin, Zhoushuai; Jiang, Wandong; Wang, Guifen; Sun, Ying; Xiao, Wei

    2018-01-01

    Ubiquitination of proliferating cell nuclear antigen (PCNA) plays an important role in DNA damage response. Ectopic expression of PCNA fused at either terminus with ubiquitin (Ub) lacking two C-terminal glycine residues induces translesion DNA synthesis which resembles synthesis mediated by PCNA monoubiquitination. PCNA fused with Ub containing the C-terminal Gly residues at the C-terminus can be further polyubiquitinated in a Gly-dependent manner, which inhibits cell proliferation and induces ATR-dependent replication checkpoint. In this study, we surprisingly found that PCNA fused to a head-to-tail linear Ub chain induces apoptosis in a Ub chain length-dependent manner. Further investigation revealed that the apoptotic effect is actually induced by the linear Ub chain independently from PCNA, as the Ub chain fused to GFP or an epitope tag still efficiently induces apoptosis. It is revealed that the artificial linear Ub chain differs from endogenously encoded linear Ub chains in that its Ubs contain a Ub-G76S substitution, making the Ub chain resistant to cleavage by deubiquitination enzymes. We demonstrated in this study that ectopic expression of the artificial Ub chain alone in cultured human cancer cells is sufficient to inhibit tumor growth in a xenograft mouse model, making the linear Ub chain a putative anti-cancer agent.

  4. Growth and development rates have different thermal responses.

    Science.gov (United States)

    Forster, Jack; Hirst, Andrew G; Woodward, Guy

    2011-11-01

    Growth and development rates are fundamental to all living organisms. In a warming world, it is important to determine how these rates will respond to increasing temperatures. It is often assumed that the thermal responses of physiological rates are coupled to metabolic rate and thus have the same temperature dependence. However, the existence of the temperature-size rule suggests that intraspecific growth and development are decoupled. Decoupling of these rates would have important consequences for individual species and ecosystems, yet this has not been tested systematically across a range of species. We conducted an analysis on growth and development rate data compiled from the literature for a well-studied group, marine pelagic copepods, and use an information-theoretic approach to test which equations best describe these rates. Growth and development rates were best characterized by models with significantly different parameters: development has stronger temperature dependence than does growth across all life stages. As such, it is incorrect to assume that these rates have the same temperature dependence. We used the best-fit models for these rates to predict changes in organism mass in response to temperature. These predictions follow a concave relationship, which complicates attempts to model the impacts of increasing global temperatures on species body size.

  5. Predicting Madura cattle growth curve using non-linear model

    Science.gov (United States)

    Widyas, N.; Prastowo, S.; Widi, T. S. M.; Baliarti, E.

    2018-03-01

    Madura cattle is Indonesian native. It is a composite breed that has undergone hundreds of years of selection and domestication to reach nowadays remarkable uniformity. Crossbreeding has reached the isle of Madura and the Madrasin, a cross between Madura cows and Limousine semen emerged. This paper aimed to compare the growth curve between Madrasin and one type of pure Madura cows, the common Madura cattle (Madura) using non-linear models. Madura cattles are kept traditionally thus reliable records are hardly available. Data were collected from small holder farmers in Madura. Cows from different age classes (5years) were observed, and body measurements (chest girth, body length and wither height) were taken. In total 63 Madura and 120 Madrasin records obtained. Linear model was built with cattle sub-populations and age as explanatory variables. Body weights were estimated based on the chest girth. Growth curves were built using logistic regression. Results showed that within the same age, Madrasin has significantly larger body compared to Madura (plogistic models fit better for Madura and Madrasin cattle data; with the estimated MSE for these models were 39.09 and 759.28 with prediction accuracy of 99 and 92% for Madura and Madrasin, respectively. Prediction of growth curve using logistic regression model performed well in both types of Madura cattle. However, attempts to administer accurate data on Madura cattle are necessary to better characterize and study these cattle.

  6. Division-Based, Growth Rate Diversity in Bacteria

    Directory of Open Access Journals (Sweden)

    Ghislain Y. Gangwe Nana

    2018-05-01

    Full Text Available To investigate the nature and origins of growth rate diversity in bacteria, we grew Escherichia coli and Bacillus subtilis in liquid minimal media and, after different periods of 15N-labeling, analyzed and imaged isotope distributions in individual cells with Secondary Ion Mass Spectrometry. We find a striking inter- and intra-cellular diversity, even in steady state growth. This is consistent with the strand-dependent, hyperstructure-based hypothesis that a major function of the cell cycle is to generate coherent, growth rate diversity via the semi-conservative pattern of inheritance of strands of DNA and associated macromolecular assemblies. We also propose quantitative, general, measures of growth rate diversity for studies of cell physiology that include antibiotic resistance.

  7. Measurements of Protein Crystal Face Growth Rates

    Science.gov (United States)

    Gorti, S.

    2014-01-01

    Protein crystal growth rates will be determined for several hyperthermophile proteins.; The growth rates will be assessed using available theoretical models, including kinetic roughening.; If/when kinetic roughening supersaturations are established, determinations of protein crystal quality over a range of supersaturations will also be assessed.; The results of our ground based effort may well address the existence of a correlation between fundamental growth mechanisms and protein crystal quality.

  8. Linear perturbation growth at the trailing edge of a rarefaction wave

    International Nuclear Information System (INIS)

    Wouchuk, J.G.; Carretero, R.

    2003-01-01

    An analytic model for the perturbation growth inside a rarefaction wave is presented. The objective of the work is to calculate the growth of the perturbations at the trailing edge of a simple expanding wave in planar geometry. Previous numerical and analytical works have shown that the ripples at the rarefaction tail exhibit linear growth asymptotically in time [Yang et al., Phys. Fluids 6, 1856 (1994), A. Velikovich and L. Phillips, ibid. 8, 1107 (1996)]. However, closed expressions for the asymptotic value of the perturbed velocity of the trailing edge have not been reported before, except for very weak rarefactions. Explicit analytic solutions for the perturbations growing at the rarefaction trailing edge as a function of time and also for the asymptotic perturbed velocity are given, for fluids with γ<3. The limits of weak and strong rarefactions are considered and the corresponding scaling laws are given. A semi-qualitative discussion of the late time linear growth at the trailing edge ripple is presented and it is seen that the lateral mass flow induced by the sound wave fluctuations is solely responsible for that behavior. Only the rarefactions generated after the interaction of a shock wave with a contact discontinuity are considered

  9. [Linear growth retardation in children under five years of age: a baseline study].

    Science.gov (United States)

    Rissin, Anete; Figueiroa, José Natal; Benício, Maria Helena D'Aquino; Batista Filho, Malaquias

    2011-10-01

    The scope of this study was to describe the prevalence of, and analyze factors associated with, linear growth retardation in children. The baseline study analyzed 2040 children under the age of five, establishing a possible association between growth delay (height/age index non-binary variables, there was a positive association with roof type and number of inhabitants per room and a negative association with income per capita, mother's schooling and birth weight. The adjusted analysis also indicated water supply, visit from the community health agent, birth delivery location, internment for diarrhea, or for pneumonia and birth weight as significant variables. Several risk factors were identified for linear growth retardation pointing to the multi-causal aspects of the problem and highlighting the need for control measures by the various hierarchical government agents.

  10. Growth rate of YBCO-Ag superconducting single grains

    Science.gov (United States)

    Congreve, J. V. J.; Shi, Y. H.; Dennis, A. R.; Durrell, J. H.; Cardwell, D. A.

    2017-12-01

    The large scale use of (RE)Ba2Cu3O7 bulk superconductors, where RE=Y, Gd, Sm, is, in part, limited by the relatively poor mechanical properties of these inherently brittle ceramic materials. It is reported that alloying of (RE)Ba2Cu3O7 with silver enables a significant improvement in the mechanical strength of bulk, single grain samples without any detrimental effect on their superconducting properties. However, due to the complexity and number of inter-related variables involved in the top seeded melt growth (TSMG) process, the growth of large single grains is difficult and the addition of silver makes it even more difficult to achieve successful growth reliably. The key processing variables in the TSMG process include the times and temperatures of the stages within the heating profile, which can be derived from the growth rate during the growth process. To date, the growth rate of the YBa2Cu3O7-Ag system has not been reported in detail and it is this lacuna that we have sought to address. In this work we measure the growth rate of the YBCO-Ag system using a method based on continuous cooling and isothermal holding (CCIH). We have determined the growth rate by measuring the side length of the crystallised region for a number of samples for specified isothermal hold temperatures and periods. This has enabled the growth rate to be modelled and from this an optimized heating profile for the successful growth of YBCO-Ag single grains to be derived.

  11. [Peculiarities of linear growth of the melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler].

    Science.gov (United States)

    Vember, V V; Zhdanova, N N

    2001-01-01

    Results on determination of radial (linear) growth rate of melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler concerning place of their isolation and ecologic peculiarities are presented in the paper. Essential differences, as to all studied indices of the strains of C. sphaerospermum strains, isolated from premices of the ChNPP 4th unit from the control strains of this species have been established. Only strain 34 of C. sphaerospermum, isolated from the cable driving region of the "Shelter" object, which did not differ from the control strains as to all the studied indices, made the exception. The radial growth rate was 2-4 times as low and variability amplitude 10-30 times as high in strains 60 and 5-1 of C. sphaerospermum, (which suffered high radiation load), as in the control strains of this species. The radial growth rate of C. sphaerospermum studied strains was an order lower as a whole than that of A. alternata strains. All the above said evidence for implementation of K-type vital strategy by C. sphaerospermum species and in this connection one can suppose its active growth on the surface of walls and ferroconcrete structures of the ChNPP 4th unit. Absence of differences, as to the studied radial growth indices, between A. alternata strains isolated from the ChNPP 4th unit premices and control strains of the species can evidence for the existence of A. alternata species under the conditions of high radioactivity in the surviving state.

  12. Sex-Based Differences in Adelie Penguin (Pygoscelis adeliae Chick Growth Rates and Diet.

    Directory of Open Access Journals (Sweden)

    Scott Jennings

    Full Text Available Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11% as well as bill (~8% and flipper length (~3%. We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d(-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species--one krill (Euphausia crystallorophias and one fish (Pleuragramma antarctica, with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors

  13. Association between parental socio-demographic factors and declined linear growth of young children in Jakarta

    Directory of Open Access Journals (Sweden)

    Hartono Gunardi

    2018-02-01

    Full Text Available Background: In Indonesia, approximately 35.5% of children under five years old were stunted. Stunting is related to shorter adult stature, poor cognition and educational performance, low adult wages, lost productivity, and higher risk of nutrition-related chronic disease. The aim of this study was to identify parental socio-demographic risk factors of declined linear growth in children younger than 2 years old.Methods: This was a cohort-prospective study between August 2012 and May 2014 at three primary community health care centers (Puskesmas in Jakarta, Indonesia, namely Puskesmas Jatinegara, Mampang, and Tebet. Subjects were healthy children under 2 years old, in which their weight and height were measured serially (at 6–11 weeks old and 18–24 months old. The length-for-age based on those data was used to determine stature status. The serial measurement was done to detect growth pattern. Parental socio-demographic data were obtained from questionnairesResults: From the total of 160 subjects, 14 (8.7% showed declined growth pattern from normal to stunted and 10 (6.2% to severely stunted. As many as 134 (83.8% subjects showed consistent normal growth pattern. Only 2 (1.2% showed improvement in the linear growth. Maternal education duration less than 9 years (RR=2.60, 95% CI=1.23–5.46; p=0.02 showed statistically significant association with declined linear growth in children.Conclusion: Mother with education duration less than 9 years was the determining socio-demographic risk factor that contributed to the declined linear growth in children less than 2 years of age.

  14. Theoretical growth rates, periods, and pulsation constants for long-period variables

    International Nuclear Information System (INIS)

    Fox, M.W.; Wood, P.R.

    1982-01-01

    Theoretical values of the growth rate, period, and pulsation constant for the first three radial pulsation modes in red giants (Population II and galactic disk) and supergiants have been derived in the linear, nonadiabatic approximation. The effects of altering the surface boundary conditions, the effective temperature (or mixing length), and the opacity in the outer layers have been explored. In the standard models, the Q-value for the first overtone can be much larger (Q 1 1 roughly-equal0.04); in addition, the Q-value for the fundamental mode is reduced from previous values, as is the period ratio P 0 /P 1 . The growth rate for the fundamental mode is found to increase with luminosity on the giant branch while the growth rate for the first overtone decreases. Dynamical instabilities found in previous adiabatic models of extreme red giants do not occur when nonadiabatic effects are included in the models. In some massive, luminous models, period ratios P 0 /P 1 approx.7 occur when P 0 approx.2000--5000 days; it is suggested that the massive galactic supergiants and carbon stars which have secondary periods Papprox.2000--7000 days and primary periods Papprox.300--700 days are first-overtone pulsators in which the long secondary periods are due to excitation of the fundamental mode. Some other consequences of the present results are briefly discussed, with particular emphasis on the mode of pulsation of the Mira variables. Subject headings: stars: long-period variables: stars: pulsation: stars: supergiants

  15. Increased linear bone growth by GH in the absence of SOCS2 is independent of IGF-1.

    Science.gov (United States)

    Dobie, Ross; Ahmed, Syed F; Staines, Katherine A; Pass, Chloe; Jasim, Seema; MacRae, Vicky E; Farquharson, Colin

    2015-11-01

    Growth hormone (GH) signaling is essential for postnatal linear bone growth, but the relative importance of GHs actions on the liver and/or growth plate cartilage remains unclear. The importance of liver derived insulin like-growth factor-1 (IGF-1) for endochondral growth has recently been challenged. Here, we investigate linear growth in Suppressor of Cytokine Signaling-2 (SOCS2) knockout mice, which have enhanced growth despite normal systemic GH/IGF-1 levels. Wild-type embryonic ex vivo metatarsals failed to exhibit increased linear growth in response to GH, but displayed increased Socs2 transcript levels (P growth over a 12 day period. Despite this increase, IGF-1 transcript and protein levels were not increased in response to GH. In accordance with these data, IGF-1 levels were unchanged in GH-challenged postnatal Socs2(-/-) conditioned medium despite metatarsals showing enhanced linear growth. Growth-plate Igf1 mRNA levels were not elevated in juvenile Socs2(-/-) mice. GH did however elevate IGF-binding protein 3 levels in conditioned medium from GH challenged metatarsals and this was more apparent in Socs2(-/-) metatarsals. GH did not enhance the growth of Socs2(-/-) metatarsals when the IGF receptor was inhibited, suggesting that IGF receptor mediated mechanisms are required. IGF-2 may be responsible as IGF-2 promoted metatarsal growth and Igf2 expression was elevated in Socs2(-/-) (but not WT) metatarsals in response to GH. These studies emphasise the critical importance of SOCS2 in regulating GHs ability to promote bone growth. Also, GH appears to act directly on the metatarsals of Socs2(-/-) mice, promoting growth via a mechanism that is independent of IGF-1. © 2014 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

  16. Growth rate, population entropy, and perturbation theory.

    OpenAIRE

    Demetrius, L.

    1989-01-01

    This paper is concerned with the connection between two classes of population variables: measures of population growth rate—the Malthusian parameter, the net reproduction rate, the gross reproduction rate, and the mean life expectancy; and measures of demographic heterogeneity—population entropy. It is shown that the entropy functions predict the response of the growth rate parameters to perturbations in the age-specific fecundity and mortality schedule. These results are invoked to introduce...

  17. EVIDENCE ON EMPLOYMENT RATE AND ECONOMIC GROWTH

    Directory of Open Access Journals (Sweden)

    Cornelia VĂCEANU

    2014-11-01

    Full Text Available This paper explores a causal relationship between employment rate and economic growth for European Union countries, in general, and produces a structural assessment of employment on the background of labour market dynamics. Economic growth is the key in economic theory and the main source of well-being and quality of life. Since the 2008 financial crisis, most European countries have experienced job shortage and unemployment problem, but today's European economic outlook is strengthening on the bases of a GDP growing momentum. Empirical data shows, regardless the GDP's moderate positive trend, the employment rate did not increase enough. Given this, the present analysis address the question: to what extent the employment rate is affected by economic growth?

  18. Fecal Markers of Intestinal Inflammation and Permeability Associated with the Subsequent Acquisition of Linear Growth Deficits in Infants

    Science.gov (United States)

    Kosek, Margaret; Haque, Rashidul; Lima, Aldo; Babji, Sudhir; Shrestha, Sanjaya; Qureshi, Shahida; Amidou, Samie; Mduma, Estomih; Lee, Gwenyth; Yori, Pablo Peñataro; Guerrant, Richard L.; Bhutta, Zulfiqar; Mason, Carl; Kang, Gagandeep; Kabir, Mamun; Amour, Caroline; Bessong, Pascal; Turab, Ali; Seidman, Jessica; Olortegui, Maribel Paredes; Quetz, Josiane; Lang, Dennis; Gratz, Jean; Miller, Mark; Gottlieb, Michael

    2013-01-01

    Enteric infections are associated with linear growth failure in children. To quantify the association between intestinal inflammation and linear growth failure three commercially available enzyme-linked immunosorbent assays (neopterin [NEO], alpha-anti-trypsin [AAT], and myeloperoxidase [MPO]) were performed in a structured sampling of asymptomatic stool from children under longitudinal surveillance for diarrheal illness in eight countries. Samples from 537 children contributed 1,169 AAT, 916 MPO, and 954 NEO test results that were significantly associated with linear growth. When combined to form a disease activity score, children with the highest score grew 1.08 cm less than children with the lowest score over the 6-month period following the tests after controlling for the incidence of diarrheal disease. This set of affordable non-invasive tests delineates those at risk of linear growth failure and may be used for the improved assessments of interventions to optimize growth during a critical period of early childhood. PMID:23185075

  19. Associations of infant feeding and timing of linear growth and relative weight gain during early life with childhood body composition

    NARCIS (Netherlands)

    de Beer, M.; Vrijkotte, T. G. M.; Fall, C. H. D.; van Eijsden, M.; Osmond, C.; Gemke, R. J. B. J.

    2015-01-01

    Growth and feeding during infancy have been associated with later life body mass index. However, the associations of infant feeding, linear growth and weight gain relative to linear growth with separate components of body composition remain unclear. Of 5551 children with collected growth and

  20. Hatching rate and growth rate of Nothobranchius guentheri fertilized eggs after space flight

    International Nuclear Information System (INIS)

    Guo Mingzhong; Zheng Leyun; Lin Guangji; Zhong Jianxing; Yang Huosheng; Zheng Yangfu

    2012-01-01

    Hatching, abnormal, growth and survival rate of the fertilized eggs of Nothobranchius guentheri were carried by Shenzhou 7 spacecraft were studied. The results indicated that the hatching and abnormal rate were no significant difference between the spaceflight group (99.3% and 16.8%) and ground group (97.2% and 10.4%); but the growth rate of male fish from spaceflight group was significant higher (0.094 g/d) than that of ground group (0.059 g/d), leading to the significant bigger of the male fish from spaceflight group. The survival rate of spaceflight group (66.7%) was higher than the ground group (47.9%). It was concluded that there was a higher growth and survival rate of Nothobranchius guentheri fertilized eggs after space flight. (authors)

  1. A meta-analysis of cambium phenology and growth: linear and non-linear patterns in conifers of the northern hemisphere.

    Science.gov (United States)

    Rossi, Sergio; Anfodillo, Tommaso; Cufar, Katarina; Cuny, Henri E; Deslauriers, Annie; Fonti, Patrick; Frank, David; Gricar, Jozica; Gruber, Andreas; King, Gregory M; Krause, Cornelia; Morin, Hubert; Oberhuber, Walter; Prislan, Peter; Rathgeber, Cyrille B K

    2013-12-01

    Ongoing global warming has been implicated in shifting phenological patterns such as the timing and duration of the growing season across a wide variety of ecosystems. Linear models are routinely used to extrapolate these observed shifts in phenology into the future and to estimate changes in associated ecosystem properties such as net primary productivity. Yet, in nature, linear relationships may be special cases. Biological processes frequently follow more complex, non-linear patterns according to limiting factors that generate shifts and discontinuities, or contain thresholds beyond which responses change abruptly. This study investigates to what extent cambium phenology is associated with xylem growth and differentiation across conifer species of the northern hemisphere. Xylem cell production is compared with the periods of cambial activity and cell differentiation assessed on a weekly time scale on histological sections of cambium and wood tissue collected from the stems of nine species in Canada and Europe over 1-9 years per site from 1998 to 2011. The dynamics of xylogenesis were surprisingly homogeneous among conifer species, although dispersions from the average were obviously observed. Within the range analysed, the relationships between the phenological timings were linear, with several slopes showing values close to or not statistically different from 1. The relationships between the phenological timings and cell production were distinctly non-linear, and involved an exponential pattern. The trees adjust their phenological timings according to linear patterns. Thus, shifts of one phenological phase are associated with synchronous and comparable shifts of the successive phases. However, small increases in the duration of xylogenesis could correspond to a substantial increase in cell production. The findings suggest that the length of the growing season and the resulting amount of growth could respond differently to changes in environmental conditions.

  2. The effect of size and competition on tree growth rate in old-growth coniferous forests

    Science.gov (United States)

    Das, Adrian

    2012-01-01

    Tree growth and competition play central roles in forest dynamics. Yet models of competition often neglect important variation in species-specific responses. Furthermore, functions used to model changes in growth rate with size do not always allow for potential complexity. Using a large data set from old-growth forests in California, models were parameterized relating growth rate to tree size and competition for four common species. Several functions relating growth rate to size were tested. Competition models included parameters for tree size, competitor size, and competitor distance. Competitive strength was allowed to vary by species. The best ranked models (using Akaike’s information criterion) explained between 18% and 40% of the variance in growth rate, with each species showing a strong response to competition. Models indicated that relationships between competition and growth varied substantially among species. The results also suggested that the relationship between growth rate and tree size can be complex and that how we model it can affect not only our ability to detect that complexity but also whether we obtain misleading results. In this case, for three of four species, the best model captured an apparent and unexpected decline in potential growth rate for the smallest trees in the data set.

  3. Volume growth rate of acoustic neurinomas

    International Nuclear Information System (INIS)

    Laasonen, E.M.; Troupp, H.

    1986-01-01

    Of 79 acoustic neurinomas seen between June 1980 and June 1984, at least two CT scans were available for each of 23 tumours (21 patients); the scans were performed at intervals of at least 6 months. The volume growth rate of the tumours was either moderate, with a volume doubling time ranging from 205 to 545 days, or slow, with a doubling time ranging from 1090 days to no observable growth. No single clinical, radiological or histological feature correlated with any type of growth rate. However, some conclusions were drawn. If a primary CT scan is negative, at least 1 year should elapse before it is worthwhile taking another scan, even though audiological findings suggest growth; after an apparently radical removal, at least 3 years should elapse before a check CT scan is worthwhile; and if a small acoustic neurinoma is diagnosed, but for some reason not operated upon, a second CT scan should be carried out 1 year later in order to reassess the case. (orig.)

  4. Insights into crystal growth rates from a study of orbicular granitoids from western Australia

    Science.gov (United States)

    Zhang, J.; Lee, C. T.

    2017-12-01

    The purpose of this study is to develop new tools for constraining crystal growth rate in geologic systems. Of interest is the growth of crystals in magmatic systems because crystallization changes the rheology of a magma as well as provides surfaces on which bubbles can nucleate. To explore crystal growth in more detail, we conducted a case study of orbicular granitoids from western Australia. The orbicules occur as spheroids dispersed in a granitic matrix. Most orbicules have at least two to three concentric bands, composed of elongate and radially oriented hornblende surrounded by interstitial plagioclase. We show that mineral modes and hence bulk composition at the scale of the band is homogeneous from rim to core. Crystal number density decreases and crystal size increases from rim to core. These observations suggest that the orbicules crystallized rapidly from rim to core. We hypothesize that the orbicules are blobs of hot dioritic liquid injected into a cold granitic magma and subsequently cooled and solidified. Crystals stop growing when the mass transport rate tends to zero due to the low temperature. We estimated cooling timescales based on conductive cooling models, constraining crystal growth rates to be 10-6 to 10-5 m/s. We also show that the oscillatory banding is controlled by disequilibrium crystallization, wherein hornblende preferentially crystallizes, resulting in the diffusive growth of a chemical boundary layer enriched in plagioclase component, which in turns results in crystallization of plagioclase. We show that the correlation between the width of each crystallization couplet (band) with distance from orbicule rim is linear, with the slope corresponding to the square root of the ratio between chemical diffusivity in the growth medium and thermal diffusivity. We estimate chemical diffusivity of 2*10-7 m2/s, which is remarkably fast for silicate liquids but reasonable for diffusion in hot aqueous fluids, suggesting that crystallization

  5. Stunting at birth: recognition of early-life linear growth failure in the western highlands of Guatemala.

    Science.gov (United States)

    Solomons, Noel W; Vossenaar, Marieke; Chomat, Anne-Marie; Doak, Colleen M; Koski, Kristine G; Scott, Marilyn E

    2015-07-01

    Measurements of length at birth, or in the neonatal period, are challenging to obtain and often discounted for lack of validity. Hence, classical 'under-5' stunting rates have been derived from surveys on children from 6 to 59 months of age. Guatemala has a high prevalence of stunting (49.8%), but the age of onset of growth failure is not clearly defined. The objective of the study was to assess length-for-age within the first 1.5 months of life among Guatemalan infants. As part of a cross-sectional observational study, supine length was measured in young infants. Mothers' height was measured. Length-for-age Z-scores (HAZ) were generated and stunting was defined as HAZ Guatemala. Three hundred and six newborns with a median age of 19 d. The median rural HAZ was -1.56 and prevalence of stunting was 38%; the respective urban values were -1.41 and 25%. Linear regression revealed no relationship between infant age and HAZ (r = 0.101, r(2) = 0.010, P = 0.077). Maternal height explained 3% of the variability in HAZ (r = 0.171, r(2) = 0.029, P = 0.003). Stunting must be carried over from in utero growth retardation in short-stature Guatemalan mothers. As linear growth failure in this setting begins in utero, its prevention must be linked to maternal care strategies during gestation, or even before. A focus on maternal nutrition and health in an intergenerational dimension is needed to reduce its prevalence.

  6. Money Supply, Interest Rate, and Economic Growth in Cameroon: A ...

    African Journals Online (AJOL)

    Money Supply, Interest Rate, and Economic Growth in Cameroon: A Time Series ... the impacts of money and interest rate on economic growth and development. ... Money Supply, Interest Rates, Economic growth, Co-integration and Inflation.

  7. Stochastic process corrosion growth models for pipeline reliability

    International Nuclear Information System (INIS)

    Bazán, Felipe Alexander Vargas; Beck, André Teófilo

    2013-01-01

    Highlights: •Novel non-linear stochastic process corrosion growth model is proposed. •Corrosion rate modeled as random Poisson pulses. •Time to corrosion initiation and inherent time-variability properly represented. •Continuous corrosion growth histories obtained. •Model is shown to precisely fit actual corrosion data at two time points. -- Abstract: Linear random variable corrosion models are extensively employed in reliability analysis of pipelines. However, linear models grossly neglect well-known characteristics of the corrosion process. Herein, a non-linear model is proposed, where corrosion rate is represented as a Poisson square wave process. The resulting model represents inherent time-variability of corrosion growth, produces continuous growth and leads to mean growth at less-than-one power of time. Different corrosion models are adjusted to the same set of actual corrosion data for two inspections. The proposed non-linear random process corrosion growth model leads to the best fit to the data, while better representing problem physics

  8. Response of Escherichia coli growth rate to osmotic shock.

    Science.gov (United States)

    Rojas, Enrique; Theriot, Julie A; Huang, Kerwyn Casey

    2014-05-27

    It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless "stored" growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan.

  9. Can we estimate bacterial growth rates from ribosomal RNA content?

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, P.F.

    1995-12-31

    Several studies have demonstrated a strong relationship between the quantity of RNA in bacterial cells and their growth rate under laboratory conditions. It may be possible to use this relationship to provide information on the activity of natural bacterial communities, and in particular on growth rate. However, if this approach is to provide reliably interpretable information, the relationship between RNA content and growth rate must be well-understood. In particular, a requisite of such applications is that the relationship must be universal among bacteria, or alternately that the relationship can be determined and measured for specific bacterial taxa. The RNA-growth rate relationship has not been used to evaluate bacterial growth in field studies, although RNA content has been measured in single cells and in bulk extracts of field samples taken from coastal environments. These measurements have been treated as probable indicators of bacterial activity, but have not yet been interpreted as estimators of growth rate. The primary obstacle to such interpretations is a lack of information on biological and environmental factors that affect the RNA-growth rate relationship. In this paper, the available data on the RNA-growth rate relationship in bacteria will be reviewed, including hypotheses regarding the regulation of RNA synthesis and degradation as a function of growth rate and environmental factors; i.e. the basic mechanisms for maintaining RNA content in proportion to growth rate. An assessment of the published laboratory and field data, the current status of this research area, and some of the remaining questions will be presented.

  10. Linear Growth and Child Development in Burkina Faso, Ghana, and Malawi.

    Science.gov (United States)

    Prado, Elizabeth L; Abbeddou, Souheila; Adu-Afarwuah, Seth; Arimond, Mary; Ashorn, Per; Ashorn, Ulla; Brown, Kenneth H; Hess, Sonja Y; Lartey, Anna; Maleta, Kenneth; Ocansey, Eugenia; Ouédraogo, Jean-Bosco; Phuka, John; Somé, Jérôme W; Vosti, Steve A; Yakes Jimenez, Elizabeth; Dewey, Kathryn G

    2016-08-01

    We aimed to produce quantitative estimates of the associations between 4 domains of child development and linear growth during 3 periods: before birth, early infancy, and later infancy. We also aimed to determine whether several factors attenuated these associations. In 3700 children in Burkina Faso, Ghana, and Malawi, growth was measured several times from birth to age 18 months. At 18 months, language, motor, socioemotional, and executive function development were assessed. In Burkina Faso (n = 1111), personal-social development was assessed rather than the latter 2 domains. Linear growth was significantly associated with language, motor, and personal-social development but not socioemotional development or executive function. For language, the pooled adjusted estimate of the association with length-for-age z score (LAZ) at 6 months was 0.13 ± 0.02 SD, and with ΔLAZ from 6 to 18 months it was 0.11 ± 0.03 SD. For motor, these estimates were 0.16 ± 0.02 SD and 0.22 ± 0.03 SD, respectively. In 1412 children measured at birth, estimates of the association with LAZ at birth were similar (0.07-0.16 SD for language and 0.09-0.18 SD for motor development). These associations were weaker or absent in certain subsets of children with high levels of developmental stimulation or mothers who received nutritional supplementation. Growth faltering during any period from before birth to 18 months is associated with poor development of language and motor skills. Interventions to provide developmental stimulation or maternal supplementation may protect children who are faltering in growth from poor language and motor development. Copyright © 2016 by the American Academy of Pediatrics.

  11. Resistive Wall Growth Rate Measurements in the Fermilab Recycler

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, R. [Fermilab; Adamson, P. [Fermilab; Burov, A. [Fermilab; Kourbanis, I. [Fermilab

    2016-10-05

    Impedance could represent a limitation of running high intensity beams in the Fermilab recycler. With high intensity upgrades foreseen, it is important to quantify the impedance. To do this,studies have been performed measuring the growth rate of presumably the resistive wall instability. The growth rates at varying intensities and chromaticities are shown. The measured growth rates are compared to ones calculated with the resistive wall impedance.

  12. Effective Exchange Rate Classifications and Growth

    OpenAIRE

    Justin M. Dubas; Byung-Joo Lee; Nelson C. Mark

    2005-01-01

    We propose an econometric procedure for obtaining de facto exchange rate regime classifications which we apply to study the relationship between exchange rate regimes and economic growth. Our classification method models the de jure regimes as outcomes of a multinomial logit choice problem conditional on the volatility of a country's effective exchange rate, a bilateral exchange rate and international reserves. An `effective' de facto exchange rate regime classification is then obtained by as...

  13. Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis

    OpenAIRE

    Blair, David P.; Blanchard, Wade; Banks, Sam C.; Lindenmayer, David B.

    2017-01-01

    Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two spec...

  14. Dependence of total dose response of bipolar linear microcircuits on applied dose rate

    International Nuclear Information System (INIS)

    McClure, S.; Will, W.; Perry, G.; Pease, R.L.

    1994-01-01

    The effect of dose rate on the total dose radiation hardness of three commercial bipolar linear microcircuits is investigated. Total dose tests of linear bipolar microcircuits show larger degradation at 0.167 rad/s than at 90 rad/s even after the high dose rate test is followed by a room temperature plus a 100 C anneal. No systematic correlation could be found for degradation at low dose rate versus high dose rate and anneal. Comparison of the low dose rate with the high dose rate anneal data indicates that MIL-STD-883, method 1019.4 is not a worst-case test method when applied to bipolar microcircuits for low dose rate space applications

  15. Associations of infant feeding and timing of linear growth and relative weight gain during early life with childhood body composition

    NARCIS (Netherlands)

    de Beer, M.; Vrijkotte, T.G.M.; Fall, C.H.D.; Eijsden, M.; Osmond, C.; Gemke, R.J.B.J.

    2015-01-01

    Background:Growth and feeding during infancy have been associated with later life body mass index. However, the associations of infant feeding, linear growth and weight gain relative to linear growth with separate components of body composition remain unclear.Methods:Of 5551 children with collected

  16. Volume Changes After Stereotactic LINAC Radiotherapy in Vestibular Schwannoma: Control Rate and Growth Patterns

    International Nuclear Information System (INIS)

    Langenberg, Rick van de; Dohmen, Amy J.C.; Bondt, Bert J. de; Nelemans, Patty J.; Baumert, Brigitta G.; Stokroos, Robert J.

    2012-01-01

    Purpose: The purpose of this study was to evaluate the control rate of vestibular schwannomas (VS) after treatment with linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) or radiotherapy (SRT) by using a validated volumetric measuring tool. Volume-based studies on prognosis after LINAC-based SRS or SRT for VS are reported scarcely. In addition, growth patterns and risk factors predicting treatment failure were analyzed. Materials and Methods: Retrospectively, 37 VS patients treated with LINAC based SRS or SRT were analyzed. Baseline and follow-up magnetic resonance imaging scans were analyzed with volume measurements on contrast enhanced T1-weighted magnetic resonance imaging. Absence of intervention after radiotherapy was defined as “no additional intervention group, ” absence of radiological growth was defined as “radiological control group. ” Significant growth was defined as a volume change of 19.7% or more, as calculated in a previous study. Results: The cumulative 4-year probability of no additional intervention was 96.4% ± 0.03; the 4-year radiological control probability was 85.4% ± 0.1). The median follow-up was 40 months. Overall, shrinkage was seen in 65%, stable VS in 22%, and growth in 13%. In 54% of all patients, transient swelling was observed. No prognostic factors were found regarding VS growth. Previous treatment and SRS were associated with transient swelling significantly. Conclusions: Good control rates are reported for LINAC based SRS or SRT in VS, in which the lower rate of radiological growth control is attributed to the use of the more sensitive volume measurements. Transient swelling after radiosurgery is a common phenomenon and should not be mistaken for treatment failure. Previous treatment and SRS were significantly associated with transient swelling.

  17. Re-assessing copepod growth using the Moult Rate method

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Keister, J. E.; Richardson, A. J.

    2014-01-01

    Estimating growth and production rates of mesozooplankton, and copepods in particular, is important in describing flows of material and energy though pelagic systems. Over the past 30 years, the Moult Rate (MR) method has been used to estimate juvenile copepod growth rates in ∼40 papers. Yet the MR......-moulting stage, e.g. copepodite stage 5 to adult. We performed experiments with Calanus pacificus to estimate growth of stage C5 using an alternative method. We found that the error size and sign varied between mass type (i.e. DW, C and N). Recommendations for practical future assessments of growth in copepods...

  18. Divergent biparietal diameter growth rates in twin pregnancies.

    Science.gov (United States)

    Houlton, M C

    1977-05-01

    Twenty-eight twin pregnancies were monitored by serial ultrasonic cephalometry from 30 or 31 weeks' gestation. The rates of growth of the individual twins as determined by biparietal diameters were similar in 11 cases (39%) and divergent in 17 (61%). When the rates of growth were divergent, the lesser rate was always below the mean for singleton pregnancies, and the incidence of small-for-gestational-age babies was 18 of 34 (53%). It was apparent that the greater the difference in biparietal diameters within the 2 weeks preceding delivery, the higher the risk of a small-for-gestation-age baby being delivered. No comment could be made on the growth rate prior to 28 weeks except that at diagnosis there was little or no difference in biparietal diameters.

  19. Preliminary observation of genital secretions, growth rate and ...

    African Journals Online (AJOL)

    Cane rats are large terrestial rodents which have the potential to increase animal protein intake. There is paucity of information on the genital secretions and growth rate of caged cane rats. This study observed the genital secretions, growth rate, feeds, feeding and the behaviour of caged cane rats. When animals adjusted to ...

  20. Seasonal variations in ectotherm growth rates: Quantifying growth as an intermittent non steady state compensatory process

    Science.gov (United States)

    Guarini, J.-M.; Chauvaud, Laurent; Cloern, J.E.; Clavier, J.; Coston-Guarini, J.; Patry, Y.

    2011-01-01

    Generally, growth rates of living organisms are considered to be at steady state, varying only under environmental forcing factors. For example, these rates may be described as a function of light for plants or organic food resources for animals and these could be regulated (or not) by temperature or other conditions. But, what are the consequences for an individual's growth (and also for the population growth) if growth rate variations are themselves dynamic and not steady state? For organisms presenting phases of dormancy or long periods of stress, this is a crucial question. A dynamic perspective for quantifying short-term growth was explored using the daily growth record of the scallop Pecten maximus (L.). This species is a good biological model for ectotherm growth because the shell records growth striae daily. Independently, a generic mathematical function representing the dynamics of mean daily growth rate (MDGR) was implemented to simulate a diverse set of growth patterns. Once the function was calibrated with the striae patterns, the growth rate dynamics appeared as a forced damped oscillation during the growth period having a basic periodicity during two transitory phases (mean duration 43. days) and appearing at both growth start and growth end. This phase is most likely due to the internal dynamics of energy transfer within the organism rather than to external forcing factors. After growth restart, the transitory regime represents successive phases of over-growth and regulation. This pattern corresponds to a typical representation of compensatory growth, which from an evolutionary perspective can be interpreted as an adaptive strategy to coping with a fluctuating environment. ?? 2011 Elsevier B.V.

  1. Multibunch emittance growth and its corrections in S-Band linear collider

    International Nuclear Information System (INIS)

    Gao, J.

    1994-11-01

    Multibunch emittance growths caused by long range wake fields with the misalignments of accelerating structures and quadrupoles in S-Band linear collider are studied. Tolerances for the misalignment errors of accelerating structures and quadrupoles are given corresponding to different detuned+damped structures. At the end of main linac, emittance corrector (EC) is proposed to be used to reduce further the multibunch emittance. Numerical simulations show that the effect of EC is obvious (multibunch emittance can be reduced about one order of magnitude), and it is believed that this kind of EC will be necessary for future linear colliders. (author). 16 refs., 21 figs., 4 tabs

  2. Low temperature leaf photosynthesis of a Miscanthus germplasm collection correlates positively to shoot growth rate and specific leaf area

    DEFF Research Database (Denmark)

    Jiao, Xiurong; Sørensen, Kirsten Kørup; Andersen, Mathias Neumann

    2016-01-01

    and CO2 response curves were obtained from 11 of the genotypes, and shoot growth rate was measured under field conditions. Key Results A positive linear relationship was found between SLA and light-saturated photosynthesis (Asat) across genotypes, and also between shoot growth rate under cool field...... conditions and A1000 at 14 °C in a climate chamber. When lowering the temperature from 24 to 14 °C, one M. sacchariflorus exhibited significantly higher Asat and maximum photosynthetic rate in the CO2 response curve (Vmax) than other genotypes at 14 °C, except M. × giganteus ‘Hornum’. Several genotypes...... returned to their pre-chilling A1000 values when the temperature was increased to 24 °C after 24 d growth at 14 °C. Conclusions One M. sacchariflorus genotype had similar or higher photosynthetic capacity than M. × giganteus, and may be used for cultivation together with M. × giganteus or for breeding new...

  3. Resolving nanoparticle growth mechanisms from size- and time-dependent growth rate analysis

    Science.gov (United States)

    Pichelstorfer, Lukas; Stolzenburg, Dominik; Ortega, John; Karl, Thomas; Kokkola, Harri; Laakso, Anton; Lehtinen, Kari E. J.; Smith, James N.; McMurry, Peter H.; Winkler, Paul M.

    2018-01-01

    Atmospheric new particle formation occurs frequently in the global atmosphere and may play a crucial role in climate by affecting cloud properties. The relevance of newly formed nanoparticles depends largely on the dynamics governing their initial formation and growth to sizes where they become important for cloud microphysics. One key to the proper understanding of nanoparticle effects on climate is therefore hidden in the growth mechanisms. In this study we have developed and successfully tested two independent methods based on the aerosol general dynamics equation, allowing detailed retrieval of time- and size-dependent nanoparticle growth rates. Both methods were used to analyze particle formation from two different biogenic precursor vapors in controlled chamber experiments. Our results suggest that growth rates below 10 nm show much more variation than is currently thought and pin down the decisive size range of growth at around 5 nm where in-depth studies of physical and chemical particle properties are needed.

  4. Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

    Science.gov (United States)

    Van Neste, D J J; Rushton, D H

    2016-08-01

    Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Sex-Based Differences in Adélie Penguin (Pygoscelis adeliae) Chick Growth Rates and Diet

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Katie M.; Ballard, Grant; Ainley, David G.

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species—one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact the

  6. Sex-Based Differences in Adélie Penguin (Pygoscelis adeliae) Chick Growth Rates and Diet.

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Katie M; Ballard, Grant; Ainley, David G

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d(-1) faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species--one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact

  7. Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling.

    Science.gov (United States)

    Koopman, Jacob J E; van Heemst, Diana; van Bodegom, David; Bonkowski, Michael S; Sun, Liou Y; Bartke, Andrzej

    2016-03-01

    Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species.

  8. Estimation of the growth curve and heritability of the growth rate for giant panda (Ailuropoda melanoleuca) cubs.

    Science.gov (United States)

    Che, T D; Wang, C D; Jin, L; Wei, M; Wu, K; Zhang, Y H; Zhang, H M; Li, D S

    2015-03-27

    Giant panda cubs have a low survival rate during the newborn and early growth stages. However, the growth and developmental parameters of giant panda cubs during the early lactation stage (from birth to 6 months) are not well known. We examined the growth and development of giant panda cubs by the Chapman growth curve model and estimated the heritability of the maximum growth rate at the early lactation stage. We found that 83 giant panda cubs reached their maximum growth rate at approximately 75-120 days after birth. The body weight of cubs at 75 days was 4285.99 g. Furthermore, we estimated that the heritability of the maximum growth rate was moderate (h(2) = 0.38). Our study describes the growth and development of giant panda cubs at the early lactation stage and provides valuable growth benchmarks. We anticipate that our results will be a starting point for more detailed research on increasing the survival rate of giant panda cubs. Feeding programs for giant panda cubs need further improvement.

  9. Exchange Rate Fluctuation and the Nigeria Economic Growth

    Directory of Open Access Journals (Sweden)

    Lawal Adedoyin Isola

    2016-11-01

    Full Text Available The aim of this study is to investigate the impact of exchange rate fluctuation on economic growth in Nigeria within the context of four profound theories: purchasing power parity; monetary model of exchange rates; the portfolio balance approach; and the optimal currency area theory. Data was collected from the CBN statistical bulletin in Nigeria from 2003– 2013and the Autoregressive Distributed Lag (ARDL model was employed to estimate the model. In the model, real GDP (RGDP was used as the proxy for economic growth while Inflation rate (IF, Exchange rate (EXC, Interest rate (INT and Money Supply(M2 as proxies for other macroeconomic variables. The empirical results show that exchange rate fluctuation has no effect on economic growth in the long run though a short run relationship exist between the two. Based on these findings, this paper recommends that the Central bank for policy purposes should ensure that stern foreign exchange control policies are put in place in order to help in appropriate determination of the value of the exchange rate. This will in the long run help to strengthen the value of the Naira.

  10. Linear study of the precessional fishbone instability

    Science.gov (United States)

    Idouakass, M.; Faganello, M.; Berk, H. L.; Garbet, X.; Benkadda, S.

    2016-10-01

    The precessional fishbone instability is an m = n = 1 internal kink mode destabilized by a population of trapped energetic particles. The linear phase of this instability is studied here, analytically and numerically, with a simplified model. This model uses the reduced magneto-hydrodynamics equations for the bulk plasma and the Vlasov equation for a population of energetic particles with a radially decreasing density. A threshold condition for the instability is found, as well as a linear growth rate and frequency. It is shown that the mode frequency is given by the precession frequency of the deeply trapped energetic particles at the position of strongest radial gradient. The growth rate is shown to scale with the energetic particle density and particle energy while it is decreased by continuum damping.

  11. Effects of socioeconomic position and social mobility on linear growth from early childhood until adolescence

    Directory of Open Access Journals (Sweden)

    Ana Paula Muraro

    Full Text Available ABSTRACT: Objective: To assess the effect of socioeconomic position (SEP in childhood and social mobility on linear growth through adolescence in a population-based cohort. Methods: Children born in Cuiabá-MT, central-western Brazil, were evaluated during 1994 - 1999. They were first assessed during 1999 - 2000 (0 - 5 years and again during 2009 - 2011 (10 - 17 years, and their height-for-age was evaluated during these two periods.Awealth index was used to classify the SEP of each child’s family as low, medium, or high. Social mobility was categorized as upward mobility or no upward mobility. Linear mixed models were used. Results: We evaluated 1,716 children (71.4% of baseline after 10 years, and 60.6% of the families showed upward mobility, with a higher percentage among the lowest economic classes. A higher height-for-age was also observed among those from families with a high SEP both in childhood (low SEP= -0.35 z-score; high SEP= 0.15 z-score, p < 0.01 and adolescence (low SEP= -0.01 z-score; high SEP= 0.45 z-score, p < 0.01, whereas upward mobility did not affect their linear growth. Conclusion: Expressive social mobility was observed, but SEP in childhood and social mobility did not greatly influence linear growth through childhood in this central-western Brazilian cohort.

  12. Effect of selection for relative growth rate and bodyweight of mice on rate, composition and efficiency of growth

    NARCIS (Netherlands)

    Bakker, H.

    1974-01-01

    To evaluate the effect of selection for parameters of a growth curve, four selection lines and a control line were started from one base population. In the selection lines is selected for a large and a small relative growth rate between 21 and 29 days (RGH and RGL) and for a large and

  13. Growth-rate-dependent dynamics of a bacterial genetic oscillator

    Science.gov (United States)

    Osella, Matteo; Lagomarsino, Marco Cosentino

    2013-01-01

    Gene networks exhibiting oscillatory dynamics are widespread in biology. The minimal regulatory designs giving rise to oscillations have been implemented synthetically and studied by mathematical modeling. However, most of the available analyses generally neglect the coupling of regulatory circuits with the cellular “chassis” in which the circuits are embedded. For example, the intracellular macromolecular composition of fast-growing bacteria changes with growth rate. As a consequence, important parameters of gene expression, such as ribosome concentration or cell volume, are growth-rate dependent, ultimately coupling the dynamics of genetic circuits with cell physiology. This work addresses the effects of growth rate on the dynamics of a paradigmatic example of genetic oscillator, the repressilator. Making use of empirical growth-rate dependencies of parameters in bacteria, we show that the repressilator dynamics can switch between oscillations and convergence to a fixed point depending on the cellular state of growth, and thus on the nutrients it is fed. The physical support of the circuit (type of plasmid or gene positions on the chromosome) also plays an important role in determining the oscillation stability and the growth-rate dependence of period and amplitude. This analysis has potential application in the field of synthetic biology, and suggests that the coupling between endogenous genetic oscillators and cell physiology can have substantial consequences for their functionality.

  14. Variation in coral growth rates with depth at Discovery Bay, Jamaica

    Energy Technology Data Exchange (ETDEWEB)

    Huston, M

    1985-01-01

    Growth rates, determined by X-radiographic measurement of skeletal extension, decreased with depth for four of six species of coral examined at Discovery Bay, Jamaica. Growth of Porites astreoides, Montastrea annularis, Colpophyllia natans, and Siderastrea siderea decreased significantly with depth over a 1- to 30-m depth range. In Montastrea cavernosa, the highest growth rate occurred in the middle of the sampled depth range. Agaricia agaricites had no measurable change in growth rate with depth. A compilation of available growth data for Atlantic and Pacific corals shows a strong pattern of highest growth rates a short distance below the surface and a decrease with depth.

  15. Investigation of growth rate dispersion in lactose crystallisation by AFM

    Science.gov (United States)

    Dincer, T. D.; Ogden, M. I.; Parkinson, G. M.

    2014-09-01

    α-Lactose monohydrate crystals have been reported to exhibit growth rate dispersion (GRD). Variation in surface dislocations has been suggested as the cause of GRD, but this has not been further investigated to date. In this study, growth rate dispersion and the change in morphology were investigated in situ and via bottle roller experiments. The surfaces of the (0 1 0) faces of crystals were examined with Atomic Force Microscopy. Smaller, slow growing crystals tend to have smaller (0 1 0) faces with narrow bases and displayed a single double spiral in the centre of the crystal with 2 nm high steps. Additional double spirals in other crystals resulted in faster growth rates. Large, fast growing crystals were observed to have larger (0 1 0) faces with fast growth in both the a and b directions (giving a broader crystal base) with macro steps parallel to the (c direction). The number and location of spirals or existence of macro steps appears to influence the crystal morphology, growth rates and growth rate dispersion in lactose crystals.

  16. Linear spline multilevel models for summarising childhood growth trajectories: A guide to their application using examples from five birth cohorts.

    Science.gov (United States)

    Howe, Laura D; Tilling, Kate; Matijasevich, Alicia; Petherick, Emily S; Santos, Ana Cristina; Fairley, Lesley; Wright, John; Santos, Iná S; Barros, Aluísio Jd; Martin, Richard M; Kramer, Michael S; Bogdanovich, Natalia; Matush, Lidia; Barros, Henrique; Lawlor, Debbie A

    2016-10-01

    Childhood growth is of interest in medical research concerned with determinants and consequences of variation from healthy growth and development. Linear spline multilevel modelling is a useful approach for deriving individual summary measures of growth, which overcomes several data issues (co-linearity of repeat measures, the requirement for all individuals to be measured at the same ages and bias due to missing data). Here, we outline the application of this methodology to model individual trajectories of length/height and weight, drawing on examples from five cohorts from different generations and different geographical regions with varying levels of economic development. We describe the unique features of the data within each cohort that have implications for the application of linear spline multilevel models, for example, differences in the density and inter-individual variation in measurement occasions, and multiple sources of measurement with varying measurement error. After providing example Stata syntax and a suggested workflow for the implementation of linear spline multilevel models, we conclude with a discussion of the advantages and disadvantages of the linear spline approach compared with other growth modelling methods such as fractional polynomials, more complex spline functions and other non-linear models. © The Author(s) 2013.

  17. GROWTH-RATES OF SHRUBS ON DIFFERENT SOILS IN TANZANIA

    NARCIS (Netherlands)

    PRINS, HHT; VANDERJEUGD, HP

    1992-01-01

    Because little is known of growth rates of shrubs in East Africa, the growth rates of Acalypha fructicosa, Gardenia jovis-tonantis, Justicia cordata, Maerua triphylla, and Ocimum suave were measured in Lake Manyara National Park, northern Tanzania. Branch diameter increments and branch length

  18. Growth rates of shrubs on different soils in Tanzania.

    NARCIS (Netherlands)

    Prins, H.H.T.; Jeugd, van der H.P.

    1992-01-01

    Because little is known of growth rates of shrubs in East Africa, the growth rates of Acalypha fructicosa, Gardenia jovis-tonantis, Justicia cordata, Maerua triphylla, and Ocimum suave were measured in Lake Manyara National Park, northern Tanzania. Branch diameter increments and branch length

  19. Linear and Nonlinear Causality between Energy Consumption and Economic Growth: The Case of Mexico 1965–2014

    Directory of Open Access Journals (Sweden)

    Mario Gómez

    2018-03-01

    Full Text Available This paper analyzes the causal link between aggregated and disaggregated levels of energy consumption and economic growth in Mexico between 1965 and 2014, with the presence of structural breaks stemming from the series. To that end, unit root with structural breaks, cointegration, and linear and nonlinear causality tests are employed. The results show that there is a long-run relationship between production, capital, labor, and energy, and linear causal links from total and disaggregated energy consumption to economic growth. A nonlinear causality also exists from energy consumption, the transport sector, capital, and labor to output. These results support the growth hypothesis, which maintains that energy is an important input factor for economic activity and that energy conservation policies impact the economic growth in Mexico.

  20. Severe linear growth retardation in rural Zambian children: the influence of biological variables.

    NARCIS (Netherlands)

    Hautvast, J.L.A.; Tolboom, J.J.M.; Kaftwembe, E.M.; Musonda, R.M.; Mwanakasale, V.; Staveren, W.A. van; Hof, M.A. van 't; Sauerwein, R.W.; Willems, J.L.; Monnens, L.A.H.

    2000-01-01

    BACKGROUND: The prevalence of stunting in preschool children in Zambia is high; stunting has detrimental effects on concurrent psychomotor development and later working capacity. OBJECTIVE: Our objective was to investigate biological variables that may contribute to linear growth retardation in

  1. Development of linear flow rate control system for eccentric butter-fly valve

    International Nuclear Information System (INIS)

    Kwak, K. K.; Cho, S. W.; Park, J. S.; Cho, J. H.; Song, I. T.; Kim, J. G.; Kwon, S. J.; Kim, I. J.; Park, W. K.

    1999-12-01

    Butter-fly valves are advantageous over gate, globe, plug, and ball valves in a variety of installations, particularly in the large sizes. The purpose of this project development of linear flow rate control system for eccentric butter-fly valve (intelligent butter-fly valve system). The intelligent butter-fly valve system consist of a valve body, micro controller. The micro controller consist of torque control system, pressure censor, worm and worm gear and communication line etc. The characteristics of intelligent butter-fly valve system as follows: Linear flow rate control function. Digital remote control function. guard function. Self-checking function. (author)

  2. Postnatal Growth Rates of Hummingbirds : Review and New Records

    NARCIS (Netherlands)

    Freymann, Bernd P.; Schuchmann, Karl-Ludwig

    2008-01-01

    We review the published information on postnatal growth rates of hummingbirds (13 species), and report previously unpublished records for nine additional trochilid species. The allometric relationship based on the log(10)-transformed data of K (logistic growth rate constant) and body mass has a

  3. The Variance Composition of Firm Growth Rates

    Directory of Open Access Journals (Sweden)

    Luiz Artur Ledur Brito

    2009-04-01

    Full Text Available Firms exhibit a wide variability in growth rates. This can be seen as another manifestation of the fact that firms are different from one another in several respects. This study investigated this variability using the variance components technique previously used to decompose the variance of financial performance. The main source of variation in growth rates, responsible for more than 40% of total variance, corresponds to individual, idiosyncratic firm aspects and not to industry, country, or macroeconomic conditions prevailing in specific years. Firm growth, similar to financial performance, is mostly unique to specific firms and not an industry or country related phenomenon. This finding also justifies using growth as an alternative outcome of superior firm resources and as a complementary dimension of competitive advantage. This also links this research with the resource-based view of strategy. Country was the second source of variation with around 10% of total variance. The analysis was done using the Compustat Global database with 80,320 observations, comprising 13,221 companies in 47 countries, covering the years of 1994 to 2002. It also compared the variance structure of growth to the variance structure of financial performance in the same sample.

  4. Comparing Basal Area Growth Rates in Repeated Inventories: Simpson's Paradox in Forestry

    Science.gov (United States)

    Charles E. Thomas; Bernard R. Parresol

    1989-01-01

    Recent analyses of radial growth rates in southern commercial forests have shown that current rates are lower than past rates when compared diameter class by diameter class. These results have been interpreted as an indication that the growth rate of the forest is declining. In this paper, growth rates of forest populations in Alabama are studied. Basal area growth (a...

  5. Protein thermodynamics can be predicted directly from biological growth rates.

    Directory of Open Access Journals (Sweden)

    Ross Corkrey

    Full Text Available Life on Earth is capable of growing from temperatures well below freezing to above the boiling point of water, with some organisms preferring cooler and others hotter conditions. The growth rate of each organism ultimately depends on its intracellular chemical reactions. Here we show that a thermodynamic model based on a single, rate-limiting, enzyme-catalysed reaction accurately describes population growth rates in 230 diverse strains of unicellular and multicellular organisms. Collectively these represent all three domains of life, ranging from psychrophilic to hyperthermophilic, and including the highest temperature so far observed for growth (122 °C. The results provide credible estimates of thermodynamic properties of proteins and obtain, purely from organism intrinsic growth rate data, relationships between parameters previously identified experimentally, thus bridging a gap between biochemistry and whole organism biology. We find that growth rates of both unicellular and multicellular life forms can be described by the same temperature dependence model. The model results provide strong support for a single highly-conserved reaction present in the last universal common ancestor (LUCA. This is remarkable in that it means that the growth rate dependence on temperature of unicellular and multicellular life forms that evolved over geological time spans can be explained by the same model.

  6. The Relationship between Economic Growth and Money Laundering – a Linear Regression Model

    Directory of Open Access Journals (Sweden)

    Daniel Rece

    2009-09-01

    Full Text Available This study provides an overview of the relationship between economic growth and money laundering modeled by a least squares function. The report analyzes statistically data collected from USA, Russia, Romania and other eleven European countries, rendering a linear regression model. The study illustrates that 23.7% of the total variance in the regressand (level of money laundering is “explained” by the linear regression model. In our opinion, this model will provide critical auxiliary judgment and decision support for anti-money laundering service systems.

  7. Evaluating Non-Linear Regression Models in Analysis of Persian Walnut Fruit Growth

    Directory of Open Access Journals (Sweden)

    I. Karamatlou

    2016-02-01

    Full Text Available Introduction: Persian walnut (Juglans regia L. is a large, wind-pollinated, monoecious, dichogamous, long lived, perennial tree cultivated for its high quality wood and nuts throughout the temperate regions of the world. Growth model methodology has been widely used in the modeling of plant growth. Mathematical models are important tools to study the plant growth and agricultural systems. These models can be applied for decision-making anddesigning management procedures in horticulture. Through growth analysis, planning for planting systems, fertilization, pruning operations, harvest time as well as obtaining economical yield can be more accessible.Non-linear models are more difficult to specify and estimate than linear models. This research was aimed to studynon-linear regression models based on data obtained from fruit weight, length and width. Selecting the best models which explain that fruit inherent growth pattern of Persian walnut was a further goal of this study. Materials and Methods: The experimental material comprising 14 Persian walnut genotypes propagated by seed collected from a walnut orchard in Golestan province, Minoudasht region, Iran, at latitude 37◦04’N; longitude 55◦32’E; altitude 1060 m, in a silt loam soil type. These genotypes were selected as a representative sampling of the many walnut genotypes available throughout the Northeastern Iran. The age range of walnut trees was 30 to 50 years. The annual mean temperature at the location is16.3◦C, with annual mean rainfall of 690 mm.The data used here is the average of walnut fresh fruit and measured withgram/millimeter/day in2011.According to the data distribution pattern, several equations have been proposed to describesigmoidal growth patterns. Here, we used double-sigmoid and logistic–monomolecular models to evaluate fruit growth based on fruit weight and4different regression models in cluding Richards, Gompertz, Logistic and Exponential growth for evaluation

  8. Rate-compatible protograph LDPC code families with linear minimum distance

    Science.gov (United States)

    Divsalar, Dariush (Inventor); Dolinar, Jr., Samuel J. (Inventor); Jones, Christopher R. (Inventor)

    2012-01-01

    Digital communication coding methods are shown, which generate certain types of low-density parity-check (LDPC) codes built from protographs. A first method creates protographs having the linear minimum distance property and comprising at least one variable node with degree less than 3. A second method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of certain variable nodes as transmitted or non-transmitted. A third method creates families of protographs of different rates, all structurally identical for all rates except for a rate-dependent designation of the status of certain variable nodes as non-transmitted or set to zero. LDPC codes built from the protographs created by these methods can simultaneously have low error floors and low iterative decoding thresholds.

  9. Markov and semi-Markov switching linear mixed models used to identify forest tree growth components.

    Science.gov (United States)

    Chaubert-Pereira, Florence; Guédon, Yann; Lavergne, Christian; Trottier, Catherine

    2010-09-01

    Tree growth is assumed to be mainly the result of three components: (i) an endogenous component assumed to be structured as a succession of roughly stationary phases separated by marked change points that are asynchronous among individuals, (ii) a time-varying environmental component assumed to take the form of synchronous fluctuations among individuals, and (iii) an individual component corresponding mainly to the local environment of each tree. To identify and characterize these three components, we propose to use semi-Markov switching linear mixed models, i.e., models that combine linear mixed models in a semi-Markovian manner. The underlying semi-Markov chain represents the succession of growth phases and their lengths (endogenous component) whereas the linear mixed models attached to each state of the underlying semi-Markov chain represent-in the corresponding growth phase-both the influence of time-varying climatic covariates (environmental component) as fixed effects, and interindividual heterogeneity (individual component) as random effects. In this article, we address the estimation of Markov and semi-Markov switching linear mixed models in a general framework. We propose a Monte Carlo expectation-maximization like algorithm whose iterations decompose into three steps: (i) sampling of state sequences given random effects, (ii) prediction of random effects given state sequences, and (iii) maximization. The proposed statistical modeling approach is illustrated by the analysis of successive annual shoots along Corsican pine trunks influenced by climatic covariates. © 2009, The International Biometric Society.

  10. Individual Growth Rates of Nikolsky’s Viper, Vipera berus nikolskii (Squamata, Viperidae

    Directory of Open Access Journals (Sweden)

    Bondarenko Z. S.

    2016-02-01

    Full Text Available Capture-mark-recapture data was used to infer growth rates of the Nikolsky’s viper, Vipera berus nikolskii (Vedmederja, Grubant et Rudaeva, 1986, in the Eastern Ukraine. We have found that growth rate is negatively correlated with age. The difference in growth rates before maturation is not significant between different sexes. Growth rates decrease rapidly after maturation in males and females, however adult males retain significantly higher average growth rates. There is large dispersion of growth rates in the group of adult females, which is caused, probably, by alteration of complete arrest of growth in the years with reproduction and more intensive growth in the years without it. Asymptotic snout-ventral length estimated after Von Bertalanffy model was 680 mm in females and 630 mm in males. Females mature after fifth and males mature after fourth hibernation. The larger females in vipers can not be the result of higher growth rates in females, but are the outcome of a combination of other factors including different maturation time and size (older and being larger, and, perhaps, longer life span due to lower mortality. Growth rates of the Nikolsky’s viper in the nature are higher than in other species in the group of small Eurasian vipers.

  11. Classification of acute stress using linear and non-linear heart rate variability analysis derived from sternal ECG

    DEFF Research Database (Denmark)

    Tanev, George; Saadi, Dorthe Bodholt; Hoppe, Karsten

    2014-01-01

    Chronic stress detection is an important factor in predicting and reducing the risk of cardiovascular disease. This work is a pilot study with a focus on developing a method for detecting short-term psychophysiological changes through heart rate variability (HRV) features. The purpose of this pilot...... study is to establish and to gain insight on a set of features that could be used to detect psychophysiological changes that occur during chronic stress. This study elicited four different types of arousal by images, sounds, mental tasks and rest, and classified them using linear and non-linear HRV...

  12. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    OpenAIRE

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth...

  13. Growth rate characteristics of acidophilic heterotrophic organisms from mine waste rock piles

    Science.gov (United States)

    Yacob, T. W.; Silverstein, J.; Jenkins, J.; Andre, B. J.; Rajaram, H.

    2010-12-01

    Autotrophic iron oxidizing bacteria play a key role in pyrite oxidation and generation of acid mine drainage AMD. Scarcity of organic substrates in many disturbed sites insures that IOB have sufficient oxygen and other nutrients for growth. It is proposed that addition of organic carbon substrate to waste rock piles will result in enrichment of heterotrophic microorganisms limiting the role of IOB in AMD generation. Previous researchers have used the acidophilic heterotroph Acidiphilium cryptum as a model to study the effects of organic substrate addition on the pyrite oxidation/AMD cycle. In order to develop a quantitative model of effects such as competition for oxygen, it is necessary to use growth and substrate consumption rate expressions, and one approach is to choose a model strain such as A. cryptum for kinetic studies. However we have found that the growth rate characteristics of A. cryptum may not provide an accurate model of the remediation effects of organic addition to subsurface mined sites. Fluorescent in-situ hybridization (FISH) assays of extracts of mine waste rock enriched with glucose and yeast extract did not produce countable numbers of cells in the Acidiphilium genus, with a detection limit of3 x 104 cells/gram rock, despite evidence of the presence of well established heterotrophic organisms. However, an MPN enrichment produced heterotrophic population estimates of 1x107 and 1x109 cells/gram rock. Growth rate studies of A. cryptum showed that cultures took 120 hours to degrade 50% of an initial glucose concentration of 2,000 mg/L. However a mixed culture enriched from mine waste rock consumed 100% of the same amount of glucose in 24 hours. Substrate consumption data for the mixed culture were fit to a Monod growth model: {dS}/{dt} = μ_{max}S {( {X_0}/{Y} + S_0 -S )}/{(K_s +S)} Kinetic parameters were estimated utilizing a non linear regression method coupled with an ODE solver. The maximum specific growth rate of the mixed population with

  14. Retrospective analysis of seasonal ocean growth rates of two sea winter Atlantic Salmon in eastern Maine using historic scales

    Science.gov (United States)

    Izzo, Lisa K.; Zydlewski, Joseph D.

    2017-01-01

    Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout its range, with many populations at the southern extent of the distribution currently extirpated or endangered. While both one sea winter (1SW) and two sea winter (2SW) spawner numbers for the North American stocks have declined since the 1950s, the decline has been most severe in 2SW spawners. The first months at sea are considered a period of high mortality. However, early ocean mortality alone cannot explain the more pronounced decline of 2SW spawners, suggesting that the second year at sea may be more critical than previously thought. Atlantic Salmon scales collected by anglers and the state agency from 1946 to 2013 from five rivers in eastern Maine were used to estimate smolt age and ocean age of returning adults. Additionally, seasonal growth rates of maiden 2SW spawners were estimated using intercirculi measurements and linear back-calculation methods. Generalized linear mixed models (Gaussian family, log link function) were used to investigate the influence of average sea surface temperature, accumulated thermal units, the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation indices, smolt age, smolt length, postsmolt growth, and river of origin on growth rate during the oceanic migration of North American Atlantic Salmon. Results suggest that different factors influence salmon growth throughout their oceanic migration, and previous growth can be a strong predictor of future size. Growth was negatively impacted by the phase of the AMO, which has been linked to salmon abundance trends, in early spring following the postsmolt period. This is likely when the 1SW and 2SW stock components separate, and our results suggest that this period may be of interest in future work examining the disproportionate decline in 2SW spawners.

  15. A Bayes linear Bayes method for estimation of correlated event rates.

    Science.gov (United States)

    Quigley, John; Wilson, Kevin J; Walls, Lesley; Bedford, Tim

    2013-12-01

    Typically, full Bayesian estimation of correlated event rates can be computationally challenging since estimators are intractable. When estimation of event rates represents one activity within a larger modeling process, there is an incentive to develop more efficient inference than provided by a full Bayesian model. We develop a new subjective inference method for correlated event rates based on a Bayes linear Bayes model under the assumption that events are generated from a homogeneous Poisson process. To reduce the elicitation burden we introduce homogenization factors to the model and, as an alternative to a subjective prior, an empirical method using the method of moments is developed. Inference under the new method is compared against estimates obtained under a full Bayesian model, which takes a multivariate gamma prior, where the predictive and posterior distributions are derived in terms of well-known functions. The mathematical properties of both models are presented. A simulation study shows that the Bayes linear Bayes inference method and the full Bayesian model provide equally reliable estimates. An illustrative example, motivated by a problem of estimating correlated event rates across different users in a simple supply chain, shows how ignoring the correlation leads to biased estimation of event rates. © 2013 Society for Risk Analysis.

  16. PENGARUH PROFIT MARGIN, ASSETS TURNOVER DAN LEVERAGE TERHADAP SUSTAINABLE GROWTH RATE PADA PERUSAHAAN SEKTOR JASA YANG TERDAFTAR DI BURSA EFEK INDONESIA PERIODE 2010-2012

    Directory of Open Access Journals (Sweden)

    Arim Nasim

    2015-04-01

    Full Text Available This study aims to determine the effect of Profit Margin, Assets Turnover and Leverage on Sustainable Growth Rate. The variables used are profit margin, asset turnover and leverage as independent variable and sustainable growth rate as dependent variable. This study also aims to describe the state of profit margin projected by Net Profit Margin (NPM, asset turnover proxied by Total Assets Turnover (TATO, leverage which is proxied by Debt to Equity Ratio (DER and Sustainable Growth Rate (SGR Service sector. This research was conducted on service sector companies listed in Indonesia Stock Exchange 2010-2012.Data obtained from website Bursa Efek Indonesia.Teknik data analysis used is multiple linear regression and use t-statistics to test the influence of each independent variable to variable Dependent partially.Previously done classical assumption test that includes data normality test, multicolinierity test, heteroskedastisitas test and autocorrelation test.Based on data normality test, multicolinierity test, heteroscedasticity test and autocorrelation test did not found any variables that deviate from the classical assumption.From the results of research Shows that profit margin positively affect sustainable growth rate, asset turnover have positive effect to sustainable growth rate, and leverage have positive effect to sustainable growth rate.

  17. Effect of feeding frequency and feeding rate on growth of ...

    African Journals Online (AJOL)

    Effect of feeding frequency and feeding rate on growth of Oreochromis mossambicus (Teleostei: Cichlidae) fry. ... Weight gain, specific growth rate and gross food conversion ratio were significantly affected by ... AJOL African Journals Online.

  18. Insulin-like growth factor 1 (IGF-1): a growth hormone

    Science.gov (United States)

    Laron, Z

    2001-01-01

    Aim—To contribute to the debate about whether growth hormone (GH) and insulin-like growth factor 1 (IGF-1) act independently on the growth process. Methods—To describe growth in human and animal models of isolated IGF-1 deficiency (IGHD), such as in Laron syndrome (LS; primary IGF-1 deficiency and GH resistance) and IGF-1 gene or GH receptor gene knockout (KO) mice. Results—Since the description of LS in 1966, 51 patients were followed, many since infancy. Newborns with LS are shorter (42–47 cm) than healthy babies (49–52 cm), suggesting that IGF-1 has some influence on intrauterine growth. Newborn mice with IGF-1 gene KO are 30% smaller. The postnatal growth rate of patients with LS is very slow, the distance from the lowest normal centile increasing progressively. If untreated, the final height is 100–136 cm for female and 109–138 cm for male patients. They have acromicia, organomicria including the brain, heart, gonads, genitalia, and retardation of skeletal maturation. The availability of biosynthetic IGF-1 since 1988 has enabled it to be administered to children with LS. It accelerated linear growth rates to 8–9 cm in the first year of treatment, compared with 10–12 cm/year during GH treatment of IGHD. The growth rate in following years was 5–6.5 cm/year. Conclusion—IGF-1 is an important growth hormone, mediating the protein anabolic and linear growth promoting effect of pituitary GH. It has a GH independent growth stimulating effect, which with respect to cartilage cells is possibly optimised by the synergistic action with GH. PMID:11577173

  19. Growth rates of breeder reactor fuel. Final report

    International Nuclear Information System (INIS)

    Ott, K.O.

    1979-01-01

    During the contract period, a consistent formalism for the definition of the growth rates (and thus the doubling time) of breeder reactor fuel has been developed. This formalism was then extended to symbiotic operation of breeder and converter reactors. Further, an estimation prescription for the growth rate has been developed which is based upon the breeding worth factors. The characteristics of this definition have been investigated, which led to an additional integral concept, the breeding bonus

  20. Effects of lowered pH on marine phytoplankton growth rates

    DEFF Research Database (Denmark)

    Berge, Terje; Daugbjerg, Niels; Andersen, Betinna Balling

    2010-01-01

    concentration of seawater. Ocean acidification may potentially both stimulate and reduce primary production by marine phytoplankton. Data are scarce on the response of marine phytoplankton growth rates to lowered pH/increased CO2. Using the acid addition method to lower the seawater pH and manipulate...... the carbonate system, we determined in detail the lower pH limit for growth rates of 2 model species of common marine phytoplankton. We also tested whether growth and production rates of 6 other common species of phytoplankton were affected by ocean acidification (lowered to pH 7.0). The lower pH limits...... statistically similar in the pH range of ~7.0 to 8.5. Our results and literature reports on growth at lowered pH indicate that marine phytoplankton in general are resistant to climate change in terms of ocean acidification, and do not increase or decrease their growth rates according to ecological relevant...

  1. Gender-specific heart rate dynamics in severe intrauterine growth-restricted fetuses.

    Science.gov (United States)

    Gonçalves, Hernâni; Bernardes, João; Ayres-de-Campos, Diogo

    2013-06-01

    Management of intrauterine growth restriction (IUGR) remains a major issue in perinatology. The objective of this paper was the assessment of gender-specific fetal heart rate (FHR) dynamics as a diagnostic tool in severe IUGR. FHR was analyzed in the antepartum period in 15 severe IUGR fetuses and 18 controls, matched for gestational age, in relation to fetal gender. Linear and entropy methods, such as mean FHR (mFHR), low (LF), high (HF) and movement frequency (MF), approximate, sample and multiscale entropy. Sensitivities and specificities were estimated using Fisher linear discriminant analysis and the leave-one-out method. Overall, IUGR fetuses presented significantly lower mFHR and entropy compared with controls. However, gender-specific analysis showed that significantly lower mFHR was only evident in IUGR males and lower entropy in IUGR females. In addition, lower LF/(MF+HF) was patent in IUGR females compared with controls, but not in males. Rather high sensitivities and specificities were achieved in the detection of the FHR recordings related with IUGR male fetuses, when gender-specific analysis was performed at gestational ages less than 34 weeks. Severe IUGR fetuses present gender-specific linear and entropy FHR changes, compared with controls, characterized by a significantly lower entropy and sympathetic-vagal balance in females than in males. These findings need to be considered in order to achieve better diagnostic results. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Modification of cell growth rate by irradiation

    International Nuclear Information System (INIS)

    Itoh, Hisao; Takemasa, Kazuhiko; Nishiguchi, Iku; Ka, Wei-Jei; Kutsuki, Shoji; Hashimoto, Shozo

    1993-01-01

    The effect of irradiation on the proliferation kinetics of the monolayer cells has been studied. Two human cell lines with different doubling times (HeLa-P and RMUG) and two clones that have the same radiosensitivity but different doubling times (HeLa-R and HeLa-S) were irradiated with a daily dose of 2 Gy for 6 days. The number of the clonogenic cells/dish was calculated by multiplying the number of total cell/dish by the survival fraction. In the rapidly growing cells (HeLa-P, HeLa-R), the number of the clonogenic cells was not decreased by the first two fractionated irradiations, but decreased thereafter at a similar rate as by single-dose fractionation, whereas the clonogenic cell number decreased from the first fractionated irradiation in the slowly growing cells (RMUG, HeLa-S). When the proliferation of clonogenic cell number increased along with a similar growth rates that was seen in all other types of cells. Further, no correlation was seen between the growth rates of cells without irradiation and cells that received irradiation. This latter result suggests that the slow growth rate of non-irradiated cells may not be the predictive factor of the tumor cure and the interruption of radiotherapy may reduce the beneficial effect of this treatment even in slow growing tumors. (author)

  3. General methods for determining the linear stability of coronal magnetic fields

    Science.gov (United States)

    Craig, I. J. D.; Sneyd, A. D.; Mcclymont, A. N.

    1988-01-01

    A time integration of a linearized plasma equation of motion has been performed to calculate the ideal linear stability of arbitrary three-dimensional magnetic fields. The convergence rates of the explicit and implicit power methods employed are speeded up by using sequences of cyclic shifts. Growth rates are obtained for Gold-Hoyle force-free equilibria, and the corkscrew-kink instability is found to be very weak.

  4. Effect of specimen geometry on the variability in fatigue crack growth rate

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Hajime; Kondo, Tatsuo

    1982-02-01

    Fatigue crack growth tests on SA 533 grade B class 1 steel were conducted in air with both contoured double cantilever beam (CDCB) specimens and compact-tension (CT) specimens for comparison, which corresponded to the ΔK constant and ΔK increasing fatigue tests respectively. The variability of the measured values was examined statistically, and possible sources of the determined variability were discussed. The variability in the ΔK increasing fatigue tests with the CT specimens was found to be substantially greater than that in the ΔK constant fatigue tests with the CDCB specimens employed in the present study. In addition, the width of the scatter as well as in the degree of deviation from the expected linearity in da/dN versus ΔK plots were found to be varied depending on the level of ΔK in the CT specimen. Based on the results, a conclusion was drawn that constant ΔK type tests should be preferred in the tests where accuracy and reproducibility of crack growth rate measurement was of particular importance. (author)

  5. Untangling the causal relationship between tax burden distribution and economic growth in 23 OECD countries: Fresh evidence from linear and non-linear Granger causality

    Directory of Open Access Journals (Sweden)

    Sami Saafi

    2017-12-01

    Full Text Available The aim of the paper is to investigate the linear and nonlinear causality between a set of alternative tax burden ratios and economic growth in 23 OECD countries. To that end, the linear causality approach of Toda– Yamamoto (1995 and the nonparametric causality method of Kyrtsou and Labys (2006 are applied to annual data spanning from 1970 to 2014. Results obtained from the nonlinear causality test tend to reject the neutrality hypothesis for the tax structure–growth relationship in 19 of the 23 OECD countries. In the majority of the countries under investigation, the evidence is in line with the growth hypothesis where causality running from economic growth to tax burden ratios was detected in Australia, Denmark, Finland, Japan, New Zealand, and Norway. The opposite causality running from tax structure to economic growth was found in Germany, Netherlands, Portugal, and Sweden. In contrast, the neutrality hypothesis was supported in Austria, Italy, Luxembourg, and the USA, whereas the feedback hypothesis was supported in Turkey and the UK. Additional robustness checks show that when the signs of variations are taken into account, there is an asymmetric causality running from positive tax burden shocks to positive per capita GDP shocks for Belgium, France, and Turkey. Overall, our findings suggest that policy implications of the tax structure-economic growth relationships should be interpreted with caution, taking into account the test-dependent and country-specific results.

  6. COMPARISON OF GKS CALCULATED CRITICAL ION TEMPERATURE GRADIENTS AND ITG GROWTH RATES TO DIII-D MEASURED GRADIENTS AND DIFFUSIVITIES

    International Nuclear Information System (INIS)

    BAKER, DR; STAEBLER, GM; PETTY, CC; GREENFIELD, CM; LUCE, TC

    2003-01-01

    OAK-B135 The gyrokinetic equations predict that various drift type waves or modes can be unstable in a tokamak. For some of these modes, such as the ion temperature gradient (ITG) mode and the electron temperature gradient mode, there exists a critical gradient, above which the mode is unstable. Since the existence of unstable modes can cause increased transport, plasmas which are centrally heated tend to increase in temperature gradient until the modes become unstable. Under some conditions the increased transport can fix the gradient at the critical value. here they present a comparison between the measured ion temperature gradients and the critical gradient as calculated by a gyrokinetic linear stability (GKS) code. They also present the maximum linear growth rate as calculated by this code for comparison to experimentally derived transport coefficients. The results show that for low confinement mode (L-mode) discharges, the measured ion temperature gradient is significantly greater than the GKS calculated critical gradient over a large region of the plasma. This is the same region of the plasma where the ion thermal diffusivity is large. For high confinement mode (H-mode) discharges the ion temperature gradient is closer to the critical gradient, but often still greater than the critical gradient over some region. For the best H-mode discharges, the ion temperature is less than or equal to the critical gradient over the whole plasma. In general they find that the position in the plasma where the ion thermal diffusivity starts to increase rapidly is where the maximum linear growth rate is greater than the E x B shearing rate

  7. Variations in growth pattern and predictablity of liveweight growth of ...

    African Journals Online (AJOL)

    The prediction equations results for rate of liveweight growth showed that of the four models used, the quadratic function was the best predictor of liveweight growth, as indicated by the highest and significant R2 value of 90.7 %. This was closely followed by the linear function which had a significant R2 value of 88.1 %.

  8. Analytic solutions for Rayleigh-Taylor growth rates in smooth density gradients

    International Nuclear Information System (INIS)

    Munro, D.H.

    1988-01-01

    The growth rate of perturbations on the shell of a laser fusion target can be estimated as √gk , where g is the shell acceleration and k is the transverse wave number of the perturbation. This formula overestimates the growth rate, and should be modified for the effects of density gradients and/or ablation of the unstable interface. The density-gradient effect is explored here analytically. With the use of variational calculus to explore all possible density profiles, the growth rate is shown to exceed √gk/(1+kL) , where L is a typical density-gradient scale length. Density profiles actually exhibiting this minimum growth rate are found

  9. Kinetics of nickel silicide growth in silicon nanowires: From linear to square root growth

    International Nuclear Information System (INIS)

    Yaish, Y. E.; Beregovsky, M.; Katsman, A.; Cohen, G. M.

    2011-01-01

    The common practice for nickel silicide formation in silicon nanowires (SiNWs) relies on axial growth of silicide along the wire that is initiated from nickel reservoirs at the source and drain contacts. In the present work the silicide intrusions were studied for various parameters including wire diameter (25-50 nm), annealing time (15-120 s), annealing temperature (300-440 deg. C), and the quality of the initial Ni/Si interface. The silicide formation was investigated by high-resolution scanning electron microscopy, high-resolution transmission electron microscopy (TEM), and atomic force microscopy. The main part of the intrusion formed at 420 deg. C consists of monosilicide NiSi, as was confirmed by energy dispersive spectroscopy STEM, selected area diffraction TEM, and electrical resistance measurements of fully silicided SiNWs. The kinetics of nickel silicide axial growth in the SiNWs was analyzed in the framework of a diffusion model through constrictions. The model calculates the time dependence of the intrusion length, L, and predicts crossover from linear to square root time dependency for different wire parameters, as confirmed by the experimental data.

  10. Linear growth patterns in small for gestational age and preterm infants after zinc supplementation

    Directory of Open Access Journals (Sweden)

    Caecilia Nancy Setiawan

    2015-03-01

    Full Text Available Background Low birth weight (LBW infants are at risk for growth disturbances due to intrauterine zinc deficiency. Zinc supplementation is expected to improve the linear growth of LBW babies. Objective To assess the effect of zinc supplementation on linear growth in preterm and small for gestational age (SGA infants. Methods This quasi-experimental study had a pre- and post-test design. Subjects were LBW infants hospitalized in Kariadi Hospital during March-December 2011, consisted of SGA and preterm neonates. All subjects were given 5 mg of zinc syrup daily for 3 months. Subjects’ head circumference, weight, and length were measured monthly. Serum zinc levels were measured before and after supplementation. Data were analyzed with Chi-square test, independent T-test, and general linear model repeated measure. Results A total of 61 subjects were enrolled consisted of 31 preterm and 30 SGA neonates. Mean serum zinc levels in the preterm group were 168.2 (SD 54.5 μg/dL pre-supplementation and 163.6 (SD 50.7 μg/dL post-supplementation (P=0.049, while mean serum zinc levels in the SGA group were 174.8 (SD 46.6 μg/dL pre-supplementation and 167.4 (SD 49.4 μg/dL post-supplementation (P=0.271. Median percentage preterm weight and length increased from 87.3 to 102.4% in the third month (P<0.001 and from 95.8 to 103.9% in the third month (P<0.001, respectively. Median percentage SGA weight and length increased from 73.5 to 98.3% in the third month (P<0.001 and from 94.5 to 102.2% in the third month (P<0.001, respectively. Conclusion Both, the preterm and SGA infants exhibit catch-up growth after three months of zinc supplementation. [

  11. What do we know about real exchange rate non-linearities?

    DEFF Research Database (Denmark)

    Kruse, Robinson; Frömmel, Michael; Menkhoff, Lukas

    correctly and misspecified non-linear alternatives is analyzed by means of a Monte Carlo study. The chosen parametrization is obtained by real-life exchange rates. The test against ESTAR has low power against all alternatives whereas the proposed unit root test against a Markov Switching autoregressive......This research points to the serious problem of potentially misspecified alternative hypotheses when testing for unit roots in real exchange rates. We apply a popular unit root test against nonlinear ESTAR and develop a Markov Switching unit root test. The empirical power of these tests against...... model performs clearly better. An empirical application of these tests suggests that real exchange rates may indeed be explained by Markov-Switching dynamics....

  12. A quantitative theory of solid tumor growth, metabolic rate and vascularization.

    Directory of Open Access Journals (Sweden)

    Alexander B Herman

    Full Text Available The relationships between cellular, structural and dynamical properties of tumors have traditionally been studied separately. Here, we construct a quantitative, predictive theory of solid tumor growth, metabolic rate, vascularization and necrosis that integrates the relationships between these properties. To accomplish this, we develop a comprehensive theory that describes the interface and integration of the tumor vascular network and resource supply with the cardiovascular system of the host. Our theory enables a quantitative understanding of how cells, tissues, and vascular networks act together across multiple scales by building on recent theoretical advances in modeling both healthy vasculature and the detailed processes of angiogenesis and tumor growth. The theory explicitly relates tumor vascularization and growth to metabolic rate, and yields extensive predictions for tumor properties, including growth rates, metabolic rates, degree of necrosis, blood flow rates and vessel sizes. Besides these quantitative predictions, we explain how growth rates depend on capillary density and metabolic rate, and why similar tumors grow slower and occur less frequently in larger animals, shedding light on Peto's paradox. Various implications for potential therapeutic strategies and further research are discussed.

  13. Growth rate correlates negatively with protein turnover in Arabidopsis accessions.

    Science.gov (United States)

    Ishihara, Hirofumi; Moraes, Thiago Alexandre; Pyl, Eva-Theresa; Schulze, Waltraud X; Obata, Toshihiro; Scheffel, André; Fernie, Alisdair R; Sulpice, Ronan; Stitt, Mark

    2017-08-01

    Previous studies with Arabidopsis accessions revealed that biomass correlates negatively to dusk starch content and total protein, and positively to the maximum activities of enzymes in photosynthesis. We hypothesized that large accessions have lower ribosome abundance and lower rates of protein synthesis, and that this is compensated by lower rates of protein degradation. This would increase growth efficiency and allow more investment in photosynthetic machinery. We analysed ribosome abundance and polysome loading in 19 accessions, modelled the rates of protein synthesis and compared them with the observed rate of growth. Large accessions contained less ribosomes than small accessions, due mainly to cytosolic ribosome abundance falling at night in large accessions. The modelled rates of protein synthesis resembled those required for growth in large accessions, but were up to 30% in excess in small accessions. We then employed 13 CO 2 pulse-chase labelling to measure the rates of protein synthesis and degradation in 13 accessions. Small accessions had a slightly higher rate of protein synthesis and much higher rates of protein degradation than large accessions. Protein turnover was negligible in large accessions but equivalent to up to 30% of synthesised protein day -1 in small accessions. We discuss to what extent the decrease in growth in small accessions can be quantitatively explained by known costs of protein turnover and what factors may lead to the altered diurnal dynamics and increase of ribosome abundance in small accessions, and propose that there is a trade-off between protein turnover and maximisation of growth rate. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  14. Growth Rate and Relocation Movements of Common Nighthawk (Chordeiles minor) Nestlings in Relation to Age

    Science.gov (United States)

    Kramer, Gunnar R.; Chalfoun, Anna D.

    2012-01-01

    Relocation by dependent young is a survival strategy that occurs among a wide range of taxa. The Common Nighthawk (Chordeiles minor) lays its eggs on bare substrate and, once hatched, nestlings may relocate to new sites daily. We located and monitored eight Common Nighthawk nests in Grand Teton National Park, Wyoming, quantified inter-use-site distances in relation to nestling age, and calculated a nestling growth rate curve. Common Nighthawk nestlings grow in a nearly linear fashion. Nestlings moved up to 48 m in a single day and larger, older nestlings tended to move greater distances between daily use-sites.

  15. Effects of socioeconomic position and social mobility on linear growth from early childhood until adolescence.

    Science.gov (United States)

    Muraro, Ana Paula; Souza, Rita Adriana Gomes de; Rodrigues, Paulo Rogério Melo; Ferreira, Márcia Gonçalves; Sichieri, Rosely

    2017-01-01

    To assess the effect of socioeconomic position (SEP) in childhood and social mobility on linear growth through adolescence in a population-based cohort. Children born in Cuiabá-MT, central-western Brazil, were evaluated during 1994 - 1999. They were first assessed during 1999 - 2000 (0 - 5 years) and again during 2009 - 2011 (10 - 17 years), and their height-for-age was evaluated during these two periods.Awealth index was used to classify the SEP of each child's family as low, medium, or high. Social mobility was categorized as upward mobility or no upward mobility. Linear mixed models were used. We evaluated 1,716 children (71.4% of baseline) after 10 years, and 60.6% of the families showed upward mobility, with a higher percentage among the lowest economic classes. A higher height-for-age was also observed among those from families with a high SEP both in childhood (low SEP= -0.35 z-score; high SEP= 0.15 z-score, p childhood and social mobility did not greatly influence linear growth through childhood in this central-western Brazilian cohort.

  16. Cluster growth kinetics

    International Nuclear Information System (INIS)

    Dubovik, V.M.; Gal'perin, A.G.; Rikhvitskij, V.S.; Lushnikov, A.A.

    2000-01-01

    Processes of some traffic blocking coming into existence are considered as probabilistic ones. We study analytic solutions for models for the dynamics of both cluster growth and cluster growth with fragmentation in the systems of finite number of objects. Assuming rates constancy of both coalescence and fragmentation, the models under consideration are linear on the probability functions

  17. STABILITY, BIFURCATIONS AND CHAOS IN UNEMPLOYMENT NON-LINEAR DYNAMICS

    Directory of Open Access Journals (Sweden)

    Pagliari Carmen

    2013-07-01

    Full Text Available The traditional analysis of unemployment in relation to real output dynamics is based on some empirical evidences deducted from Okun’s studies. In particular the so called Okun’s Law is expressed in a linear mathematical formulation, which cannot explain the fluctuation of the variables involved. Linearity is an heavy limit for macroeconomic analysis and especially for every economic growth study which would consider the unemployment rate among the endogenous variables. This paper deals with an introductive study about the role of non-linearity in the investigation of unemployment dynamics. The main idea is the existence of a non-linear relation between the unemployment rate and the gap of GDP growth rate from its trend. The macroeconomic motivation of this idea moves from the consideration of two concatenate effects caused by a variation of the unemployment rate on the real output growth rate. These two effects are concatenate because there is a first effect that generates a secondary one on the same variable. When the unemployment rate changes, the first effect is the variation in the level of production in consequence of the variation in the level of such an important factor as labour force; the secondary effect is a consecutive variation in the level of production caused by the variation in the aggregate demand in consequence of the change of the individual disposal income originated by the previous variation of production itself. In this paper the analysis of unemployment dynamics is carried out by the use of the logistic map and the conditions for the existence of bifurcations (cycles are determined. The study also allows to find the range of variability of some characteristic parameters that might be avoided for not having an absolute unpredictability of unemployment dynamics (deterministic chaos: unpredictability is equivalent to uncontrollability because of the total absence of information about the future value of the variable to

  18. Investigating calcite growth rates using a quartz crystal microbalance with dissipation (QCM-D)

    Science.gov (United States)

    Cao, Bo; Stack, Andrew G.; Steefel, Carl I.; DePaolo, Donald J.; Lammers, Laura N.; Hu, Yandi

    2018-02-01

    Calcite precipitation plays a significant role in processes such as geological carbon sequestration and toxic metal sequestration and, yet, the rates and mechanisms of calcite growth under close to equilibrium conditions are far from well understood. In this study, a quartz crystal microbalance with dissipation (QCM-D) was used for the first time to measure macroscopic calcite growth rates. Calcite seed crystals were first nucleated and grown on sensors, then growth rates of calcite seed crystals were measured in real-time under close to equilibrium conditions (saturation index, SI = log ({Ca2+}/{CO32-}/Ksp) = 0.01-0.7, where {i} represent ion activities and Ksp = 10-8.48 is the calcite thermodynamic solubility constant). At the end of the experiments, total masses of calcite crystals on sensors measured by QCM-D and inductively coupled plasma mass spectrometry (ICP-MS) were consistent, validating the QCM-D measurements. Calcite growth rates measured by QCM-D were compared with reported macroscopic growth rates measured with auto-titration, ICP-MS, and microbalance. Calcite growth rates measured by QCM-D were also compared with microscopic growth rates measured by atomic force microscopy (AFM) and with rates predicted by two process-based crystal growth models. The discrepancies in growth rates among AFM measurements and model predictions appear to mainly arise from differences in step densities, and the step velocities were consistent among the AFM measurements as well as with both model predictions. Using the predicted steady-state step velocity and the measured step densities, both models predict well the growth rates measured using QCM-D and AFM. This study provides valuable insights into the effects of reactive site densities on calcite growth rate, which may help design future growth models to predict transient-state step densities.

  19. Growth rates of alien Oreochromis niloticus and indigenous ...

    African Journals Online (AJOL)

    Growth rates of indigenous Oreochromis mortimeri and alien Oreochromis niloticus from Lake Kariba were estimated from samples collected in 1997–2000, 2003–2005 and 2010–2011. Growth zones on scales and otoliths of O. niloticus and on the otoliths and opercula of O. mortimeri were deposited annually.

  20. Fatigue Crack Growth Rate and Stress-Intensity Factor Corrections for Out-of-Plane Crack Growth

    Science.gov (United States)

    Forth, Scott C.; Herman, Dave J.; James, Mark A.

    2003-01-01

    Fatigue crack growth rate testing is performed by automated data collection systems that assume straight crack growth in the plane of symmetry and use standard polynomial solutions to compute crack length and stress-intensity factors from compliance or potential drop measurements. Visual measurements used to correct the collected data typically include only the horizontal crack length, which for cracks that propagate out-of-plane, under-estimates the crack growth rates and over-estimates the stress-intensity factors. The authors have devised an approach for correcting both the crack growth rates and stress-intensity factors based on two-dimensional mixed mode-I/II finite element analysis (FEA). The approach is used to correct out-of-plane data for 7050-T7451 and 2025-T6 aluminum alloys. Results indicate the correction process works well for high DeltaK levels but fails to capture the mixed-mode effects at DeltaK levels approaching threshold (da/dN approximately 10(exp -10) meter/cycle).

  1. Growth rates, grazing, sinking, and iron limitation of equatorial Pacific phytoplankton

    International Nuclear Information System (INIS)

    Chavez, F.P.; Buck, K.R.; Coale, K.H.; Martin, J.H.; DiTullio, G.R.; Welschmeyer, N.A.; Barber, R.T.; Jacobson, A.C.

    1991-01-01

    Concentrations of phytoplankton and NO 3 are consistently low and high in surface waters of the oceanic eastern and central equatorial Pacific, and phytoplankton populations are dominated by small solitary phytoplankton. Growth rates of natural phytoplankton populations, needed to assess the relative importance of many of the processes considered in the equatorial Pacific, were estimated by several methods. The growth rates of natural phytoplankton populations were found to be ∼0.7 d -1 or 1 biomass doubling d -1 and were similar for all methods. To keep this system in its observed balance requires that loss rates approximate observed growth rates. Grazing rates, measured with a dilution grazing experiment, were high, accounting for a large fraction of the daily production. Additions of various forms of Fe to 5-7-d incubations utilizing ultraclean techniques resulted in significant shifts in autotrophic and heterotrophic assemblages between initial samples, controls, and Fe enrichments, which were presumably due to Fe, grazing by both protistan and metazoan components, and incubation artifacts. Estimated growth rates of small pennate diatoms showed increases in Fe enrichments with respect to controls. The growth rates of the pennate diatoms were similar to those estimated for the larger size fraction of the natural populations

  2. Partial drying accelerates bacterial growth recovery to rewetting

    DEFF Research Database (Denmark)

    Meisner, Annelein; Leizeaga, Ainara; Rousk, Johannes

    2017-01-01

    , bacterial growth rates increase immediately in a linear fashion. In the Type 2 pattern, bacterial growth rates increase exponentially after a lag period. However, soils are often only partially dried. Partial drying (higher remaining moisture content before rewetting) may be considered a less harsh...

  3. Sales Growth Rate Forecasting Using Improved PSO and SVM

    Directory of Open Access Journals (Sweden)

    Xibin Wang

    2014-01-01

    Full Text Available Accurate forecast of the sales growth rate plays a decisive role in determining the amount of advertising investment. In this study, we present a preclassification and later regression based method optimized by improved particle swarm optimization (IPSO for sales growth rate forecasting. We use support vector machine (SVM as a classification model. The nonlinear relationship in sales growth rate forecasting is efficiently represented by SVM, while IPSO is optimizing the training parameters of SVM. IPSO addresses issues of traditional PSO, such as relapsing into local optimum, slow convergence speed, and low convergence precision in the later evolution. We performed two experiments; firstly, three classic benchmark functions are used to verify the validity of the IPSO algorithm against PSO. Having shown IPSO outperform PSO in convergence speed, precision, and escaping local optima, in our second experiment, we apply IPSO to the proposed model. The sales growth rate forecasting cases are used to testify the forecasting performance of proposed model. According to the requirements and industry knowledge, the sample data was first classified to obtain types of the test samples. Next, the values of the test samples were forecast using the SVM regression algorithm. The experimental results demonstrate that the proposed model has good forecasting performance.

  4. Do fish growth rates correlate with PCB body burdens?

    Science.gov (United States)

    Andrew L. Rypel; David R.. Bayne

    2010-01-01

    We evaluated whether growth rates of six fish species correlated with PCB concentrations in a moderately-to-heavily polluted freshwater ecosystem. Using a large dataset (n ¼ 984 individuals), and after accounting for growth effects related to fish age, habitat, sex, and lipids, growth correlated significantly, but positively with lipid-corrected PCB concentrations for...

  5. Linear theory of equatorial spread F

    International Nuclear Information System (INIS)

    Hudson, M.K.; Kennel, C.F.

    1975-01-01

    A fluid dispersion relation for the drift and interchange (Rayleigh-Taylor) modes in a collisional plasma forms the basis for a linear theory of equatorial spread F. The collisional drift mode growth rate will exceed the growth rate of the Rayleigh-Taylor mode at short perpendicular wavelengths and density gradient scale lengths, and the drift mode can grow on top side as well as on bottom side density gradients. However, below the F peak, where spread F predominates, it is concluded that both the drift and the Rayleigh-Taylor modes contribute to the total spread F spectrum, the Rayleigh-Taylor mode dominating at long and the drift mode at short perpendicular wavelengths above the ion Larmor radius

  6. On the growth rate of the foliicolous lichen Strigula elegans

    NARCIS (Netherlands)

    Wilde-Duyfjes, de B.E.E.

    1967-01-01

    The diametral growth rate of the foliicolous lichen Strigula elegans (Fée) Müll. Arg., measured under natural conditions in the African tropical rainforest, has been established to amount to (0.7-)3-3-6(-8) mm annually. As compared to the diametral growth rate of lichens from temperate regions,

  7. Study on the limiting acceleration rate in the VLEPP linear accelerator

    International Nuclear Information System (INIS)

    Balakin, V.E.; Brezhnev, O.N.; Zakhvatkin, M.N.

    1987-01-01

    To realize the design of colliding linear electron-positron beams it is necessary to solve the radical problem of production of accelerating structure with acceleration rate of approximately 100 MeV/m which can accelerate 10 12 particles in a bunch. Results of experimental studies of the limiting acceleration rate in the VLEPP accelerating structure are presented. Accelerating sections of different length were tested. When testing sections 29 cm long the acceleration rate of 55 MeV/m was attained, and for 1 m section the value reached 40 MeV/m. The maximum rate of acceleration (90 MeV/m) was attained when electric field intensity on the structure surface constituted more than 150 MV/m

  8. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Zoltán Németh

    2016-11-01

    Full Text Available Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L−1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.

  9. Measuring the linear heat generation rate of a nuclear reactor fuel pin

    International Nuclear Information System (INIS)

    Smith, R.D.

    1981-01-01

    A miniature gamma thermometer is described which is capable of travelling through bores distributed in an array through a nuclear reactor core and measure the linear heat generation rate of the fuel pins. (U.K.)

  10. Bistable Bacterial Growth Rate in Response to Antibiotics with Low Membrane Permeability

    Science.gov (United States)

    Elf, Johan; Nilsson, Karin; Tenson, Tanel; Ehrenberg, Måns

    2006-12-01

    We demonstrate that growth rate bistability for bacterial cells growing exponentially at a fixed external antibiotic concentration can emerge when the cell wall permeability for the drug is low and the growth rate sensitivity to the intracellular drug concentration is high. Under such conditions, an initially high growth rate can remain high, due to dilution of the intracellular drug concentration by rapid cell volume increase, while an initially low growth rate can remain low, due to slow cell volume increase and insignificant drug dilution. Our findings have implications for the testing of novel antibiotics on growing bacterial strains.

  11. Circadian cycles in growth and feeding rates of heterotrophic protist plankton

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Strom, S.L.

    2004-01-01

    Growth and feeding rates of four species of planktonic marine heterotrophic protists showed pronounced diel cycles. In most cases, rates were higher during the day and lower at night. However, for the ciliate Strobilidium sp., growth was highest at night. In another ciliate species, Balanion...... comatum, no day-night difference in growth and feeding rates was found. Maintenance of day-night rate differences during 24-h exposures to continuous darkness demonstrated that most of these protists had circadian cycles. The heterotrophic dinoflagellate Oxyrrhis marina exhibited a clear irradiance...... to culturing in a day: night light cycle in O. marina and found that resetting the circadian cycle in this dinoflagellate temporarily arrested growth and feeding. We suggest that protists use a time-integrated light threshold rather than an instantaneous irradiance to maintain the circadian cell cycle...

  12. Non-linear effects of the U.S. Monetary Policy in the Long Run

    OpenAIRE

    Olmos, Lorena; Sanso Frago, Marcos

    2014-01-01

    We find non-linearities in the U.S. long-run relationships among trend inflation, growth rate and financial frictions. Moreover, our results show that mismeasurements of the natural rate of interest deviate the trend inflation from its target, which is especially clear when monetary policy reacts preventively against inflation deviations. The long-run growth rate, the trend inflation and the natural rate of interest, specified as time-varying, are jointly estimated over the period 1960:Q1-201...

  13. Evidence of A Bimodal US GDP Growth Rate Distribution: A Wavelet Approach

    Directory of Open Access Journals (Sweden)

    Sandro Claudio Lera

    2017-04-01

    Full Text Available We present a quantitative characterisation of the fluctuations of the annualized growth rate of the real US GDP per capita at many scales, using a wavelet transform analysis of two data sets, quarterly data from 1947 to 2015 and annual data from 1800 to 2010. The chosen mother wavelet (first derivative of the Gaussian function applied to the logarithm of the real US GDP per capita provides a robust estimation of the instantaneous growth rate at different scales. Our main finding is that business cycles appear at all scales and the distribution of GDP growth rates can be well approximated by a bimodal function associated to a series of switches between regimes of strong growth rate $\\rho_\\text{high}$ and regimes of low growth rate $\\rho_\\text{low}$. The succession of such two regimes compounds to produce a remarkably stable long term average real annualized growth rate of 1.6% from 1800 to 2010 and $\\approx 2.0\\%$ since 1950, which is the result of a subtle compensation between the high and low growth regimes that alternate continuously. Thus, the overall growth dynamics of the US economy is punctuated, with phases of strong growth that are intrinsically unsustainable, followed by corrections or consolidation until the next boom starts. We interpret these findings within the theory of "social bubbles" and argue as a consequence that estimations of the cost of the 2008 crisis may be misleading. We also interpret the absence of strong recovery since 2008 as a protracted low growth regime $\\rho_\\text{low}$ associated with the exceptional nature of the preceding large growth regime.

  14. Numerical Analysis of Inlet Gas-Mixture Flow Rate Effects on Carbon Nanotube Growth Rate

    Directory of Open Access Journals (Sweden)

    B. Zahed

    2013-01-01

    Full Text Available The growth rate and uniformity of Carbon Nano Tubes (CNTs based on Chemical Vapor Deposition (CVD technique is investigated by using a numerical model. In this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal CVD reactor at atmospheric pressure. Based on the gas phase and surface reactions, released carbon atoms are grown as CNTs on the iron catalysts at the reactor hot walls. The effect of inlet gas-mixture flow rate, on CNTs growth rate and its uniformity is discussed. In addition the velocity and temperature profile and also species concentrations throughout the reactor are presented.

  15. Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

    Energy Technology Data Exchange (ETDEWEB)

    Roark, E B; Guilderson, T P; Dunbar, R B; Ingram, B L

    2006-01-13

    The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimens as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.

  16. Non-linear and non-symmetric exchange-rate adjustment: new evidence from medium and high inflation countries

    OpenAIRE

    Arghyrou, MG; Boinet, V; Martin, C

    2003-01-01

    This paper analyses a model of non-linear exchange rate adjustment that extends the literature by allowing asymmetric responses to over- and under-valuations. Applying the model to Greece and Turkey, we find that adjustment is asymmetric and that exchange rates depend on the sign as well as the magnitude of deviations, being more responsive to over-valuations than under-valuations. Our findings support and extend the argument that non-linear models of exchange rate adjustment c...

  17. Using time-dependent models to investigate body condition and growth rate of the giant gartersnake

    Science.gov (United States)

    Coates, P.S.; Wylie, G.D.; Halstead, B.J.; Casazza, Michael L.

    2009-01-01

    Identifying links between phenotypic attributes and fitness is a primary goal of reproductive ecology. Differences in within-year patterns of body condition between sexes of gartersnakes in relation to reproduction and growth are not fully understood. We conducted an 11-year field study of body condition and growth rate of the giant gartersnake Thamnophis gigas across 13 study areas in the Central Valley of California, USA. We developed a priori mixed effects models of body condition index (BCI), which included covariates of time, sex and snout-vent length and reported the best-approximating models using an information theoretic approach. Also, we developed models of growth rate index (GRI) using covariates of sex and periods based on reproductive behavior. The largest difference in BCI between sexes, as predicted by a non-linear (cubic) time model, occurred during the mating period when female body condition (0.014??0.001 se) was substantially greater than males (-0.027??0.002 se). Males likely allocated energy to search for mates, while females likely stored energy for embryonic development. We also provided evidence that males use more body energy reserves than females during hibernation, perhaps because of different body temperatures between sexes. We found GRI of male snakes was substantially lower during the mating period than during a non-mating period, which indicated that a trade-off existed between searching for mates and growth. These findings contribute to our understanding of snake ecology in a Mediterranean climate. ?? 2009 The Zoological Society of London.

  18. GROWTH RATE DISPERSION (GRD OF THE (010 FACE OF BORAX CRYSTALS IN FLOWING SOLUTION

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available The growth rates of borax crystals from aqueous solutions in the (010 direction at various flow rates were measured. The observed variations of the growth rate can be represented by a normal distribution.  It was found that there is no correlation between growth rate distribution and solution flow under these experimental conditions.   Keywords: Growth rate dispersion (GRD, borax, flow rate

  19. Bacterial growth on surfaces: Automated image analysis for quantification of growth rate-related parameters

    DEFF Research Database (Denmark)

    Møller, S.; Sternberg, Claus; Poulsen, L. K.

    1995-01-01

    species-specific hybridizations with fluorescence-labelled ribosomal probes to estimate the single-cell concentration of RNA. By automated analysis of digitized images of stained cells, we determined four independent growth rate-related parameters: cellular RNA and DNA contents, cell volume......, and the frequency of dividing cells in a cell population. These parameters were used to compare physiological states of liquid-suspended and surfacegrowing Pseudomonas putida KT2442 in chemostat cultures. The major finding is that the correlation between substrate availability and cellular growth rate found...

  20. Catch-Up Growth Occurs after Diarrhea in Early Childhood123

    Science.gov (United States)

    Richard, Stephanie A.; Black, Robert E.; Gilman, Robert H.; Guerrant, Richard L.; Kang, Gagandeep; Lanata, Claudio F.; Mølbak, Kåre; Rasmussen, Zeba A.; Sack, R. Bradley; Valentiner-Branth, Palle; Checkley, William

    2014-01-01

    Diarrhea and linear growth faltering continue to burden low-income countries and are among the most important contributors to poor health during early childhood. Diarrhea is thought to adversely affect linear growth, but catch-up growth can occur if no additional insults are experienced. We sought to characterize catch-up growth in relation to diarrhea burden in a multisite dataset of 1007 children. Using longitudinal anthropometry and diarrheal surveillance data from 7 cohort studies in 4 countries, we examined the relation between diarrhea prevalence and growth in 3- to 6-mo periods using linear mixed-effect models. Growth during each period was calculated as a function of age using linear splines. We incorporated the longitudinal prevalence of diarrhea in both current and previous periods into the model. Diarrhea during the current period was associated with slower linear and ponderal growth. Faster (catch-up) growth in length was observed in children with no diarrhea in age groups immediately after an age group in which diarrhea was experienced [age group >6–12 mo: 0.03 mm/mo for each percentage diarrhea prevalence in the previous period (95% CI: 0.007, 0.06) relative to 11.3 mm/mo mean growth rate; age group >12–18 mo: 0.04 mm/mo (95% CI: 0.02, 0.06) relative to 8.9 mm/mo mean growth rate; age group >18–24 mo: 0.04 mm/mo (95% CI: 0.003, 0.09) relative to 7.9 mm/mo mean growth rate]. The associations were stronger in boys than in girls when separate models were run. Similar results were observed when weight was the outcome variable. When diarrheal episodes are followed by diarrhea-free periods in the first 2 y of life, catch-up growth is observed that may allow children to regain their original trajectories. The finding of a greater effect of diarrhea on linear growth in boys than in girls was unexpected and requires additional study. Diarrhea burdens are high throughout the first 2 y of life in these study sites, therefore reducing the likelihood of

  1. Metabolic enzyme cost explains variable trade-offs between microbial growth rate and yield.

    Directory of Open Access Journals (Sweden)

    Meike T Wortel

    2018-02-01

    Full Text Available Microbes may maximize the number of daughter cells per time or per amount of nutrients consumed. These two strategies correspond, respectively, to the use of enzyme-efficient or substrate-efficient metabolic pathways. In reality, fast growth is often associated with wasteful, yield-inefficient metabolism, and a general thermodynamic trade-off between growth rate and biomass yield has been proposed to explain this. We studied growth rate/yield trade-offs by using a novel modeling framework, Enzyme-Flux Cost Minimization (EFCM and by assuming that the growth rate depends directly on the enzyme investment per rate of biomass production. In a comprehensive mathematical model of core metabolism in E. coli, we screened all elementary flux modes leading to cell synthesis, characterized them by the growth rates and yields they provide, and studied the shape of the resulting rate/yield Pareto front. By varying the model parameters, we found that the rate/yield trade-off is not universal, but depends on metabolic kinetics and environmental conditions. A prominent trade-off emerges under oxygen-limited growth, where yield-inefficient pathways support a 2-to-3 times higher growth rate than yield-efficient pathways. EFCM can be widely used to predict optimal metabolic states and growth rates under varying nutrient levels, perturbations of enzyme parameters, and single or multiple gene knockouts.

  2. Linear growth and child development in low- and middle-income countries: a meta-analysis.

    Science.gov (United States)

    Sudfeld, Christopher R; McCoy, Dana Charles; Danaei, Goodarz; Fink, Günther; Ezzati, Majid; Andrews, Kathryn G; Fawzi, Wafaie W

    2015-05-01

    The initial years of life are critical for physical growth and broader cognitive, motor, and socioemotional development, but the magnitude of the link between these processes remains unclear. Our objective was to produce quantitative estimates of the cross-sectional and prospective association of height-for-age z score (HAZ) with child development. Observational studies conducted in low- and middle-income countries (LMICs) presenting data on the relationship of linear growth with any measure of child development among children children ≤ 2 years old was +0.24 (95% confidence interval [CI], 0.14-0.33; I(2) = 53%) and +0.09 for children > 2 years old (95% CI, 0.05-0.12; I(2) = 78%). Prospectively, each unit increase in HAZ for children ≤ 2 years old was associated with a +0.22-SD increase in cognition at 5 to 11 years after multivariate adjustment (95% CI, 0.17-0.27; I(2) = 0%). HAZ was also significantly associated with earlier walking age and better motor scores (P development. Effective interventions that reduce linear growth restriction may improve developmental outcomes; however, integration with environmental, educational, and stimulation interventions may produce larger positive effects. Copyright © 2015 by the American Academy of Pediatrics.

  3. Nationwide Macroeconomic Variables and the Growth Rate of Bariatric Surgeries in Brazil.

    Science.gov (United States)

    Cazzo, Everton; Ramos, Almino Cardoso; Pareja, José Carlos; Chaim, Elinton Adami

    2018-06-06

    The effect of nationwide economic issues on the necessary expansion in the number of bariatric procedures remains unclear. This study aims to determine whether there are correlations between the growth rate in the number of bariatric surgeries and the major macroeconomic variables over time in Brazil. It is a nationwide analysis regarding the number of bariatric surgeries in Brazil and the main national macroeconomic variables from 2003 through 2016: gross domestic product (GDP), inflation rate, and the unemployment rate, as well as the evolution in the number of registered bariatric surgeons. There were significant positive correlations of the growth rate of surgeries with the early variations of the GDP (R = 0.5558; p = 0.04863) and of the overall health expenditure per capita (R = 0.78322; p = 0.00259). The growth rate of the number of bariatric surgeries was not correlated with the unemployment and inflation rates, as well as with the growth rate of available bariatric surgeons. There were direct relationships between the growth rate of bariatric surgeries and the evolutions of the GDP and health care expenditure per capita. These variables appear to influence the nationwide offer of bariatric surgery.

  4. Age class, longevity and growth rate relationships: protracted growth increases in old trees in the eastern United States.

    Science.gov (United States)

    Johnson, Sarah E; Abrams, Marc D

    2009-11-01

    This study uses data from the International Tree-Ring Data Bank website and tree cores collected in the field to explore growth rate (basal area increment, BAI) relationships across age classes (from young to old) for eight tree species in the eastern US. These species represent a variety of ecological traits and include those in the genera Populus, Quercus, Pinus, Tsuga and Nyssa. We found that most trees in all age classes and species exhibit an increasing BAI throughout their lives. This is particularly unusual for trees in the older age classes that we expected to have declining growth in the later years, as predicted by physiological growth models. There exists an inverse relationship between growth rate and increasing age class. The oldest trees within each species have consistently slow growth throughout their lives, implying an inverse relationship between growth rate and longevity. Younger trees (trees when they are of the same age resulting from a higher proportion of fast-growing trees in these young age classes. Slow, but increasing, BAI in the oldest trees in recent decades is a continuation of their growth pattern established in previous centuries. The fact that they have not shown a decreasing growth rate in their old age contradicts physiological growth models and may be related to the stimulatory effects of global change phenomenon (climate and land-use history).

  5. Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient.

    Science.gov (United States)

    Gentilesca, Tiziana; Rita, Angelo; Brunetti, Michele; Giammarchi, Francesco; Leonardi, Stefano; Magnani, Federico; van Noije, Twan; Tonon, Giustino; Borghetti, Marco

    2018-07-01

    In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m -2  y -1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites. © 2018 John Wiley & Sons Ltd.

  6. Orbit width scaling of TAE instability growth rate

    International Nuclear Information System (INIS)

    Wong, H.V.; Berk, H.L.; Breizman, B.N.

    1995-07-01

    The growth rate of Toroidal Alfven Eigenmodes (TAE) driven unstable by resonant coupling of energetic charged particles is evaluated in the ballooning limit over a wide range of parameters. All damping effects are ignored. Variations in orbit width, aspect ratio, and the ratio of alfven velocity to energetic particle birth velocity, are explored. The relative contribution of passing and trapped particles, and finite Larmor radius effects, are also examined. The phase space location of resonant particles with interact strongly with the modes is described. The accuracy of the analytic results with respect to growth rate magnitude and parametric dependence is investigated by comparison with numerical results

  7. Orbit width scaling of TAE instability growth rate

    International Nuclear Information System (INIS)

    Wong, H.V.; Berk, H.L.; Breizman, B.N.

    1995-01-01

    The growth rate of toroidal Alfven eigenmodes (TAEs) driven unstable by resonant coupling of energetic charged particles is evaluated in the 'ballooning' limit over a wide range of parameters. All damping effects are ignored. Variations in orbit width, aspect ratio and the ratio of Alfven velocity to energetic particle 'birth' velocity are explored. The relative contribution of passing and trapped particles, and finite Larmor radius effects, are also examined. The phase space location of resonant particles that interact strongly with the modes is described. The accuracy of the analytic results with respect to growth rate magnitude and parametric dependence is investigated by comparison with numerical results. (author). 16 refs, 8 figs

  8. Growth rate regulated genes and their wide involvement in the Lactococcus lactis stress responses

    Directory of Open Access Journals (Sweden)

    Redon Emma

    2008-07-01

    Full Text Available Abstract Background The development of transcriptomic tools has allowed exhaustive description of stress responses. These responses always superimpose a general response associated to growth rate decrease and a specific one corresponding to the stress. The exclusive growth rate response can be achieved through chemostat cultivation, enabling all parameters to remain constant except the growth rate. Results We analysed metabolic and transcriptomic responses of Lactococcus lactis in continuous cultures at different growth rates ranging from 0.09 to 0.47 h-1. Growth rate was conditioned by isoleucine supply. Although carbon metabolism was constant and homolactic, a widespread transcriptomic response involving 30% of the genome was observed. The expression of genes encoding physiological functions associated with biogenesis increased with growth rate (transcription, translation, fatty acid and phospholipids metabolism. Many phages, prophages and transposon related genes were down regulated as growth rate increased. The growth rate response was compared to carbon and amino-acid starvation transcriptomic responses, revealing constant and significant involvement of growth rate regulations in these two stressful conditions (overlap 27%. Two regulators potentially involved in the growth rate regulations, llrE and yabB, have been identified. Moreover it was established that genes positively regulated by growth rate are preferentially located in the vicinity of replication origin while those negatively regulated are mainly encountered at the opposite, thus indicating the relationship between genes expression and their location on chromosome. Although stringent response mechanism is considered as the one governing growth deceleration in bacteria, the rigorous comparison of the two transcriptomic responses clearly indicated the mechanisms are distinct. Conclusion This work of integrative biology was performed at the global level using transcriptomic analysis

  9. Unusual growth rate during cystic echinococcosis.

    Science.gov (United States)

    Valour, Florent; Khenifer, Safia; Della-Schiava, Nellie; Cotte, Eddy; Guibert, Benoit; Wallon, Martine; Durupt, Stéphane; Durieu, Isabelle

    2014-04-01

    Cystic echinococcosis is a world wild zoonosis caused by Echinococcus granulosus, leading to hepatic and lung cysts with a usually slight growth rate. We report the case of an 82year-old Algerian woman with hepatic and lung cystic echinococcosis with a 10-fold size increase in 6months. Copyright © 2013. Published by Elsevier Ireland Ltd.

  10. Exponential Growth of Nonlinear Ballooning Instability

    International Nuclear Information System (INIS)

    Zhu, P.; Hegna, C. C.; Sovinec, C. R.

    2009-01-01

    Recent ideal magnetohydrodynamic (MHD) theory predicts that a perturbation evolving from a linear ballooning instability will continue to grow exponentially in the intermediate nonlinear phase at the same linear growth rate. This prediction is confirmed in ideal MHD simulations. When the Lagrangian compression, a measure of the ballooning nonlinearity, becomes of the order of unity, the intermediate nonlinear phase is entered, during which the maximum plasma displacement amplitude as well as the total kinetic energy continues to grow exponentially at the rate of the corresponding linear phase.

  11. The effect of non-uniform mass loading on the linear, temporal development of particle-laden shear layers

    Energy Technology Data Exchange (ETDEWEB)

    Senatore, Giacomo [Department of Aerospace Engineering, Universita di Pisa, Pisa 56122 (Italy); Davis, Sean; Jacobs, Gustaaf, E-mail: gjacobs@mail.sdsu.edu [Department of Aerospace Engineering and Engineering Mechanics, San Diego State University, San Diego, 92182 California (United States)

    2015-03-15

    The effect of non-uniformity in bulk particle mass loading on the linear development of a particle-laden shear layer is analyzed by means of a stochastic Eulerian-Eulerian model. From the set of governing equations of the two-fluid model, a modified Rayleigh equation is derived that governs the linear growth of a spatially periodic disturbance. Eigenvalues for this Rayleigh equation are determined numerically using proper conditions at the co-flowing gas and particle interface locations. For the first time, it is shown that non-uniform loading of small-inertia particles (Stokes number (St) <0.2) may destabilize the inviscid mixing layer development as compared to the pure-gas flow. The destabilization is triggered by an energy transfer rate that globally flows from the particle phase to the gas phase. For intermediate St (1 < St < 10), a maximum stabilizing effect is computed, while at larger St, two unstable modes may coexist. The growth rate computations from linear stability analysis are verified numerically through simulations based on an Eulerian-Lagrangian (EL) model based on the inviscid Euler equations and a point particle model. The growth rates found in numerical experiments using the EL method are in very good agreement with growth rates from the linear stability analysis and validate the destabilizing effect induced by the presence of particles with low St.

  12. A panel data investigation of real exchange rate misalignment and growth

    Directory of Open Access Journals (Sweden)

    Flávio Vilela Vieira

    2012-09-01

    Full Text Available The paper investigates the role of real exchange rate misalignment on long-run growth for a set of ninety countries using time series data from 1980 to 2004. We first estimate a panel data model (fixed and random effects for the real exchange rate in order to produce estimates of the equilibrium real exchange rate and this is then used to construct measures of real exchange rate misalignment. We provide an alternative set of estimates of RER misalignment using panel cointegration methods. The results for the two-step System GMM panel growth models indicate that the coefficients for real exchange rate misalignment are positive for different model specification and samples, which means that a more depreciated (appreciated real exchange rate helps (harms long-run growth. The estimated coefficients are higher for developing and emerging countries.

  13. The effect of rumen content transfer on rate of bacteria and protozoa growth

    International Nuclear Information System (INIS)

    Suharyono; M Winugroho; Y Widiati; S Marijati

    1998-01-01

    The aims the experiment wants to know the benefit of rate of microbial protein in rumen content and to complete the information that isolates is useful for ruminant animals feed. The result indicated that buffaloes from East Nusa Tenggara is the best when they are used as donor rumen transfer making isolate. When rumen of ongole cattle generation was mixed in rumen content of buffaloes from East Nusa Tenggara and incubated 48 h, the rate of bacteria cell growth is better than rate of protozoa cell growth comparing to the other animals. The values are 30.99 mg/h/100 ml and 24.92 mg.h/100 ml respectively. The results of isolate selection in 48 h incubation indicated that treatment F is the best. The results rates of bacteria cell growth and rate of protozoa's cell growth are 26.96 mg/h/100 ml and 2.53 mg/h/100 respectively. The result of in vitro study indicated that pH and ammonia concentration support the rate of bacteria cell growth and do not cause the toxicity of microbes and animal . The rate of bacteria cell growth on D treatment is significant to A,B, and C treatments. The values are 21.44 mg/h/100 ml. 7.99; 13.13; and 13.38 mg/h/100 ml respectively. The result rates of protozoa's cell growth tends lower than rates of bacteria cell. The overall conclusion is a lower or a higher rate of microorganism cell growth depends on the environment condition. (author)

  14. The frequency effect on the fatigue crack growth rate of 304 stainless steel

    International Nuclear Information System (INIS)

    Shih, Y.-S.; Chen, J.-J.

    1999-01-01

    Under cyclic loading condition, the fatigue crack growth (FCG) rate governed by stress intensity factor and stress ratio is well known; Walker's equation, Forman's equation and Elber's equation are typical formulae to describe the fatigue crack growth rate. However, the loading frequency effect on the fatigue crack growth rate has yet to be explored. Recently, studies have focused on the loading frequency effect on some visco-elastic materials, and have provided a clearer understanding of the frequency effect on the fatigue crack growth rate. In a physical sense, knowledge about the loading frequency effect on the fatigue crack growth rate for 304 stainless steel is still lacking. James conducted a lot of experiments, and through data analysis, he concluded an evaluation equation which is based upon the experimental illustration. In this study, the physical properties of the material are used to illustrate the modification of fatigue crack growth rate, and a new formula which is based upon the modified Forman's equation, is provided. (orig.)

  15. Non-linear analysis of solid propellant burning rate behavior

    Energy Technology Data Exchange (ETDEWEB)

    Junye Wang [Zhejiang Univ. of Technology, College of Mechanical and Electrical Engineering, Hanzhou (China)

    2000-07-01

    The parametric analysis of the thermal wave model of the non-steady combustion of solid propellants is carried out under a sudden compression. First, to observe non-linear effects, solutions are obtained using a computer under prescribed pressure variations. Then, the effects of rearranging the spatial mesh, additional points, and the time step on numerical solutions are evaluated. Finally, the behaviour of the thermal wave combustion model is examined under large heat releases (H) and a dynamic factor ({beta}). The numerical predictions show that (1) the effect of a dynamic factor ({beta}), related to the magnitude of dp/dt, on the peak burning rate increases as the value of beta increases. However, unsteady burning rate 'runaway' does not appear and will return asymptotically to ap{sup n}, when {beta}{>=}10.0. The burning rate 'runaway' is a numerical difficulty, not a solution to the models. (2) At constant beta and m, the amplitude of the burning rate increases with increasing H. However, the increase in the burning rate amplitude is stepwise, and there is no apparent intrinsic instability limit. A damped oscillation of burning rate occurs when the value of H is less. However, when H>1.0, the state of an intrinsically unstable model is composed of repeated, amplitude spikes, i.e. an undamped oscillation occurs. (3) The effect of the time step on the peak burning rate increases as H increases. (Author)

  16. Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

    International Nuclear Information System (INIS)

    Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

    2014-01-01

    With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

  17. DKDP crystal growth controlled by cooling rate

    Science.gov (United States)

    Xie, Xiaoyi; Qi, Hongji; Shao, Jianda

    2017-08-01

    The performance of deuterated potassium dihydrogen phosphate (DKDP) crystal directly affects beam quality, energy and conversion efficiency in the Inertial Confinement Fusion(ICF)facility, which is related with the initial saturation temperature of solution and the real-time supersaturation during the crystal growth. However, traditional method to measure the saturation temperature is neither efficient nor accurate enough. Besides, the supersaturation is often controlled by experience, which yields the higher error and leads to the instability during the crystal growth. In this paper, DKDP solution with 78% deuteration concentration is crystallized in different temperatures. We study the relation between solubility and temperature of DKDP and fit a theoretical curve with a parabola model. With the model, the measurement of saturation temperature is simplified and the control precision of the cooling rate is improved during the crystal growth, which is beneficial for optimizing the crystal growth process.

  18. 210Pb-226Ra chronology reveals rapid growth rate of Madrepora oculata and Lophelia pertusa on world's largest cold-water coral reef

    Directory of Open Access Journals (Sweden)

    N. Tisnérat-Laborde

    2012-03-01

    Full Text Available Here we show the use of the 210Pb-226Ra excess method to determine the growth rate of two corals from the world's largest known cold-water coral reef, Røst Reef, north of the Arctic circle off Norway. Colonies of each of the two species that build the reef, Lophelia pertusa and Madrepora oculata, were collected alive at 350 m depth using a submersible. Pb and Ra isotopes were measured along the major growth axis of both specimens using low level alpha and gamma spectrometry and trace element compositions were studied. 210Pb and 226Ra differ in the way they are incorporated into coral skeletons. Hence, to assess growth rates, we considered the exponential decrease of initially incorporated 210Pb, as well as the increase in 210Pb from the decay of 226Ra and contamination with 210Pb associated with Mn-Fe coatings that we were unable to remove completely from the oldest parts of the skeletons. 226Ra activity was similar in both coral species, so, assuming constant uptake of 210Pb through time, we used the 210Pb-226Ra chronology to calculate growth rates. The 45.5 cm long branch of M. oculata was 31 yr with an average linear growth rate of 14.4 ± 1.1 mm yr−1 (2.6 polyps per year. Despite cleaning, a correction for Mn-Fe oxide contamination was required for the oldest part of the colony; this correction corroborated our radiocarbon date of 40 yr and a mean growth rate of 2 polyps yr−1. This rate is similar to the one obtained in aquarium experiments under optimal growth conditions. For the 80 cm-long L. pertusa colony, metal-oxide contamination remained in both the middle and basal part of the coral skeleton despite cleaning, inhibiting similar age and growth rate estimates. The youngest part of the colony was free of metal oxides and this 15 cm section had an estimated a growth rate of 8 mm yr−1, with high uncertainty (~1 polyp every two to three years. We are less certain of this 210Pb growth rate estimate which is within the lowermost

  19. Evaluation of linear heat rates for the power-to-melt tests on 'JOYO' using the Monte-Carlo code 'MVP'

    International Nuclear Information System (INIS)

    Yokoyama, Kenji; Ishikawa, Makoto

    2000-04-01

    The linear heat rates of the power-to-melt (PTM) tests, performed with B5D-1 and B5D-2 subassemblies on the Experimental Fast Reactor 'JOYO', are evaluated with the continuous energy Monte-Carlo code, MVP. We can apply a whole core model to MVP, but it takes very long time for the calculation. Therefore, judging from the structure of B5D subassembly, we used the MVP code to calculate the radial distribution of linear heat rate and used the deterministic method to calculate the axial distribution. We also derived the formulas for this method. Furthermore, we evaluated the error of the linear heat rate, by evaluating the experimental error of the reactor power, the statistical error of Monte-Carlo method, the calculational model error of the deterministic method and so on. On the other hand, we also evaluated the burnup rate of the B5D assembly and compared with the measured value in the post-irradiation test. The main results are following: B5D-1 (B5101, F613632, core center). Linear heat rate: 600 W/cm±2.2%. Burnup rate: 0.977. B5D-2 (B5214, G80124, core center). Linear heat rate: 641 W/cm±2.2%. Burnup rate: 0.886. (author)

  20. Linear Growth and Fat and Lean Tissue Gain during Childhood: Associations with Cardiometabolic and Cognitive Outcomes in Adolescent Indian Children.

    Science.gov (United States)

    Krishnaveni, Ghattu V; Veena, Sargoor R; Srinivasan, Krishnamachari; Osmond, Clive; Fall, Caroline H D

    2015-01-01

    We aimed to determine how linear growth and fat and lean tissue gain during discrete age periods from birth to adolescence are related to adolescent cardiometabolic risk factors and cognitive ability. Adolescents born to mothers with normal glucose tolerance during pregnancy from an Indian birth cohort (N = 486, age 13.5 years) had detailed anthropometry and measurements of body fat (fat%), fasting plasma glucose, insulin and lipid concentrations, blood pressure and cognitive function. Insulin resistance (HOMA-IR) was calculated. These outcomes were examined in relation to birth measurements and statistically independent measures (conditional SD scores) representing linear growth, and fat and lean tissue gain during birth-1, 1-2, 2-5, 5-9.5 and 9.5-13.5 years in 414 of the children with measurements at all these ages. Birth length and linear growth at all ages were positively associated with current height. Fat gain, particularly during 5-9.5 years was positively associated with fat% at 13.5 years (0.44 SD per SD [99.9% confidence interval: 0.29,0.58]). Greater fat gain during mid-late childhood was associated with higher systolic blood pressure (5-9.5 years: 0.23 SD per SD [0.07,0.40]) and HOMA-IR (5-9.5 years: 0.24 [0.08,0.40], 9.5-13.5 years: 0.22 [0.06,0.38]). Greater infant growth (up to age 2 years) in linear, fat or lean components was unrelated to cardiometabolic risk factors or cognitive function. This study suggests that factors that increase linear, fat and lean growth in infancy have no adverse cardiometabolic effects in this population. Factors that increase fat gain in mid-late childhood may increase cardiometabolic risk, without any benefit to cognitive abilities.

  1. Linear Growth and Fat and Lean Tissue Gain during Childhood: Associations with Cardiometabolic and Cognitive Outcomes in Adolescent Indian Children.

    Directory of Open Access Journals (Sweden)

    Ghattu V Krishnaveni

    Full Text Available We aimed to determine how linear growth and fat and lean tissue gain during discrete age periods from birth to adolescence are related to adolescent cardiometabolic risk factors and cognitive ability.Adolescents born to mothers with normal glucose tolerance during pregnancy from an Indian birth cohort (N = 486, age 13.5 years had detailed anthropometry and measurements of body fat (fat%, fasting plasma glucose, insulin and lipid concentrations, blood pressure and cognitive function. Insulin resistance (HOMA-IR was calculated. These outcomes were examined in relation to birth measurements and statistically independent measures (conditional SD scores representing linear growth, and fat and lean tissue gain during birth-1, 1-2, 2-5, 5-9.5 and 9.5-13.5 years in 414 of the children with measurements at all these ages.Birth length and linear growth at all ages were positively associated with current height. Fat gain, particularly during 5-9.5 years was positively associated with fat% at 13.5 years (0.44 SD per SD [99.9% confidence interval: 0.29,0.58]. Greater fat gain during mid-late childhood was associated with higher systolic blood pressure (5-9.5 years: 0.23 SD per SD [0.07,0.40] and HOMA-IR (5-9.5 years: 0.24 [0.08,0.40], 9.5-13.5 years: 0.22 [0.06,0.38]. Greater infant growth (up to age 2 years in linear, fat or lean components was unrelated to cardiometabolic risk factors or cognitive function.This study suggests that factors that increase linear, fat and lean growth in infancy have no adverse cardiometabolic effects in this population. Factors that increase fat gain in mid-late childhood may increase cardiometabolic risk, without any benefit to cognitive abilities.

  2. Study on the PWSCC Crack Growth Rate for Steam Generator Tubing

    International Nuclear Information System (INIS)

    Kang, Shin Hoo; Hwang, Il Soon; Lim, Jun; Lee, Seung Gi; Ryu, Kyung Ha

    2008-03-01

    Using in-situ Raman spectroscopy and crack growth rate lest system in simulated PWR primary water environment, the relationship between the oxide film chemistry and the PWSCC growth rate has been studied. We used I/2T compact tension specimen and disk specimen made of Alloy 182 and Alloy 600 for crack growth rate test and in-situ Raman spectroscopy measurement. Test was made in a refreshed autoclave with 30 cc STP / kg of dissolved hydrogen concentration. Conductivity, pH, dissolved hydrogen and oxygen concentration were continuously monitored at the outlet. The crack growth rate was measured by using switching DCPD technique under cyclinc triangular loading and at the same time oxide phase was determined by using in-situ Raman spectra at the elevation of the temperature. Additionally Raman spectroscopy was achieved for oxide phase transition of Alloy 600 according to the temperature and dissolved hydrogen concentration, 2 and 30cc STP / kg

  3. Potential production and growth analysis of local variety and Americana variety of soybean (Glycine max (L) Merril)

    International Nuclear Information System (INIS)

    Sumakud, M.Y.M.A.

    2000-01-01

    Soybean needs high radiation intensity for photosynthesis process; therefore 100 percent of the sunlight are needed. Due to increasing the soybean production, the environment factor such as climate, soil and management are needed. One of the environment factor that influence the growth and dry matter production is radiation. This research done was to see the potential production of local variety and Americana variety by observing the total radiation absorption, temperature, rainfall and humidity. Therefore the objective of this research was to know the potential production in tropic area in soybean. If the production is mainly determined by the high growth rate or the length of phase linear or both of them also by the efficiency of radiation that received by the plant. The method of this research was carried out by using completed randomized design, with three replications. The result showed that the growth and the production of soybean are determined by growth rate (Cm) and the length of growth linear (tm). Dry matter of soybean is determined by growth rate instead of the length of growth linear, for efficiency of radiation are not significant. Pod formation is determined by the growth rate, content of pods is determined by the length of linear growth

  4. Long-term growth rates and effects of bleaching in Acropora hyacinthus

    Science.gov (United States)

    Gold, Zachary; Palumbi, Stephen R.

    2018-03-01

    Understanding the response of coral growth to natural variation in the environment, as well as to acute temperature stress under current and future climate change conditions, is critical to predicting the future health of coral reef ecosystems. As such, ecological surveys are beginning to focus on corals that live in high thermal stress environments to understand how future coral populations may adapt to climate change. We investigated the relationship between coral growth, thermal microhabitat, symbionts type, and thermal acclimatization of four species of the Acropora hyacinthus complex in back-reef lagoons in American Samoa. Coral growth was measured from August 2010 to April 2016 using horizontal planar area of coral colonies derived from photographs and in situ maximum width measurements. Despite marked intraspecific variation, we found that planar colony growth rates were significantly different among cryptic species. The highly heat tolerant A. hyacinthus variant "HE" increased in area an average of 2.9% month-1 (0.03 cm average mean radial extension month-1). By contrast, the three less tolerant species averaged 6.1% (0.07 cm average mean radial extension month-1). Planar growth rates were 40% higher on average in corals harboring Clade C versus Clade D symbiont types, although marked inter-colony variation in growth rendered this difference nonsignificant. Planar growth rates for all four species dropped to near zero following a 2015 bleaching event, independent of the visually estimated percent area of bleaching. Within 1 yr, growth rates recovered to previous levels, confirming previous studies that found sublethal effects of thermal stress on coral growth. Long-term studies of individual coral colonies provide an important tool to measure impacts of environmental change and allow integration of coral physiology, genetics, symbionts, and microclimate on reef growth patterns.

  5. Growth rate change driven by external perturbation in the azuki bean weevil

    CERN Document Server

    Fukano, T

    2003-01-01

    In laboratory experiments we obtain that the apparent growth rate of the population becomes larger than one under the normal condition, triggered by the external perturbation as the removal of individuals. The changed growth rate is stable for a while. We also propose a simple model of population dynamics allowing both matching and mis-matching the trend of the external perturbation, and show that the growth rate of the model population is changeable and stable to some extent.

  6. Growth rate change driven by external perturbation in the azuki bean weevil

    International Nuclear Information System (INIS)

    Fukano, Takao; Gunji, Yukio-Pegio

    2003-01-01

    In laboratory experiments we obtain that the apparent growth rate of the population becomes larger than one under the normal condition, triggered by the external perturbation as the removal of individuals. The changed growth rate is stable for a while. We also propose a simple model of population dynamics allowing both matching and mis-matching the trend of the external perturbation, and show that the growth rate of the model population is changeable and stable to some extent

  7. Cell Size and Growth Rate Are Modulated by TORC2-Dependent Signals.

    Science.gov (United States)

    Lucena, Rafael; Alcaide-Gavilán, Maria; Schubert, Katherine; He, Maybo; Domnauer, Matthew G; Marquer, Catherine; Klose, Christian; Surma, Michal A; Kellogg, Douglas R

    2018-01-22

    The size of all cells, from bacteria to vertebrates, is proportional to the growth rate set by nutrient availability, but the underlying mechanisms are unknown. Here, we show that nutrients modulate cell size and growth rate via the TORC2 signaling network in budding yeast. An important function of the TORC2 network is to modulate synthesis of ceramide lipids, which play roles in signaling. TORC2-dependent control of ceramide signaling strongly influences both cell size and growth rate. Thus, cells that cannot make ceramides fail to modulate their growth rate or size in response to changes in nutrients. PP2A associated with the Rts1 regulatory subunit (PP2A Rts1 ) is embedded in a feedback loop that controls TORC2 signaling and helps set the level of TORC2 signaling to match nutrient availability. Together, the data suggest a model in which growth rate and cell size are mechanistically linked by ceramide-dependent signals arising from the TORC2 network. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Single machine scheduling with time-dependent linear deterioration and rate-modifying maintenance

    OpenAIRE

    Rustogi, Kabir; Strusevich, Vitaly A.

    2015-01-01

    We study single machine scheduling problems with linear time-dependent deterioration effects and maintenance activities. Maintenance periods (MPs) are included into the schedule, so that the machine, that gets worse during the processing, can be restored to a better state. We deal with a job-independent version of the deterioration effects, that is, all jobs share a common deterioration rate. However, we introduce a novel extension to such models and allow the deterioration rates to change af...

  9. Influence of Crucible Support Rod on the Growth Rate and Temperature Gradient in a Bridgman Growth of Tin Crystal

    OpenAIRE

    IMASHIMIZU, Yuji; MIURA, Koji; KAMATA, Masaki; WATANABE, Jiro

    2003-01-01

    Bridgman growth of tincrystal was carried out in a graphite crucible that was fixed on a quartz support rod or a copper one. The growth rate and axial temperature distribution were examined by recording the temperature variation with time at each of four prescribed positions in the solid-liquidsystem during solidification, l) Actual growth rate of crystal increased with progress of solidification while the furnace elevated at a constant rate, but the tendency was different depending on the ty...

  10. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    Science.gov (United States)

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  11. Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents.

    Science.gov (United States)

    Martin, Thomas E; Oteyza, Juan C; Mitchell, Adam E; Potticary, Ahva L; Lloyd, Penn

    2015-03-01

    Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.

  12. Ergodicity, hidden bias and the growth rate gain

    Science.gov (United States)

    Rochman, Nash D.; Popescu, Dan M.; Sun, Sean X.

    2018-05-01

    Many single-cell observables are highly heterogeneous. A part of this heterogeneity stems from age-related phenomena: the fact that there is a nonuniform distribution of cells with different ages. This has led to a renewed interest in analytic methodologies including use of the ‘von Foerster equation’ for predicting population growth and cell age distributions. Here we discuss how some of the most popular implementations of this machinery assume a strong condition on the ergodicity of the cell cycle duration ensemble. We show that one common definition for the term ergodicity, ‘a single individual observed over many generations recapitulates the behavior of the entire ensemble’ is implied by the other, ‘the probability of observing any state is conserved across time and over all individuals’ in an ensemble with a fixed number of individuals but that this is not true when the ensemble is growing. We further explore the impact of generational correlations between cell cycle durations on the population growth rate. Finally, we explore the ‘growth rate gain’—the phenomenon that variations in the cell cycle duration leads to an improved population-level growth rate—in this context. We highlight that, fundamentally, this effect is due to asymmetric division.

  13. Effect of neutron irradiation on hatching rate of eggs and growth rate of chicken

    International Nuclear Information System (INIS)

    Liu Yubin; Zhao Jide; Liu Shengdian; Xy Xiuwei

    1995-01-01

    It was proved through 3 years of experiments and productions that after the eggs of AA meat chickens being irradiated by 14 MeV fast neutron, the hatching rate and the survival rate as well the weight of commercial chickens increased greatly. In addition it is found that the optimum neutron fluence for hatching and growth rate is 6.2 x 10 5 n·cm -2

  14. CHRONIC UNSTABILITY AND POTENTIAL GROWTH RATE: TURKISH EXPERIENCE, 1960-2006

    Directory of Open Access Journals (Sweden)

    MUSTAFA İSMİHAN

    2013-06-01

    Full Text Available This study investigates the role of macroeconomic instability on potential growth rate of output in Turkey over the period 1960-2006. In doing so, it also attempts to estimate the potential growth rate of Turkish economy over the sample period by using Hodrick-Prescott filter and model based on production function approach. Descriptive and empirical results suggest that Turkish economy suffered from a significant output loss during the chronic instability episodes, between the mid-1970s and 2001. A significant fall in macroeconomic instability has provided the main contribution to the achievement of the recent high growth episode (2002-2006 of Turkish economy. However, in order to continue the desired high growth performance in near future it is necessary to accelerate both human and physical capital formation while preserving stability.

  15. Growth, Mortality and Exploitation Rates of Sarotherodon ...

    African Journals Online (AJOL)

    Evans

    ABSTRACT. Sarotherodon melanotheron population of Dominli Lagoon in the Western Region of Ghana was studied for its growth and mortality parameters as well as exploitation rate. The study generally aimed at providing basic information necessary for the assessment and management of the fish stock in the lagoon.

  16. Growth trajectories of mathematics achievement: Longitudinal tracking of student academic progress.

    Science.gov (United States)

    Mok, Magdalena M C; McInerney, Dennis M; Zhu, Jinxin; Or, Anthony

    2015-06-01

    A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). This study aimed at modelling the mathematics growth of students over a span of 6 years from Grade 3 to Grade 9. The sample comprised secondary longitudinal data collected in three waves from n = 866 Hong Kong students when they were in Grade 3, Grade 6, and Grade 9. Mathematics achievement was measured thrice on a vertical scale linked with anchor items. Linear and nonlinear latent growth models were used to assess students' growth. Gender differences were also examined. A nonlinear latent growth curve with a decelerated rate had a good fit to the data. Initial achievement and growth rate were negatively correlated. No gender difference was found. Mathematics growth from Grade 6 to Grade 9 was slower than that from Grade 3 to Grade 6. Students with lower initial achievement improved at a faster rate than those who started at a higher level. Gender did not affect growth rate. © 2014 The British Psychological Society.

  17. Linear and nonlinear causality between sectoral electricity consumption and economic growth: Evidence from Taiwan

    International Nuclear Information System (INIS)

    Yang, Cheng-Lang; Lin, Hung-Pin; Chang, Chih-Heng

    2010-01-01

    This study investigates the linear and nonlinear causality between the total electricity consumption (TEC) and real gross domestic production (RGDP). Unlike previous literature, we solve the undetermined relation between RGDP and electricity consumption by classifying TEC into industrial sector consumption (ISC) and residential sector consumption (RSC) as well as investigating how TEC, ISC, and RSC influence Taiwan's RGDP. By using the Granger's linear causality test, it is shown that (i) there is a bidirectional causality among TEC, ISC, and RGDP, but a neutrality between RSC and RGDP with regard to the linear causality and (ii) there is still a bidirectional causality between TEC and RGDP, but a unidirectional causality between RSC and RGDP with regard to the nonlinear causality. On the basis of (i) and (ii), we suggest that the electricity policy formulators loosen the restriction on ISC and limit RSC in order to achieve the goal of economic growth.

  18. Stainless steels: general considerations and rates of crack growth

    International Nuclear Information System (INIS)

    Chator, T.

    1992-05-01

    This report describes the different types of stainless steels, and presents the laws governing the rates of crack growth for several stainless steels extensively used for the manufacture of structures in nuclear power plants. The laws are not discussed in detail in the report. After a brief review of the development of stainless steels, the main categories of stainless steels, their mechanical characteristics and corrosion resistance, are presented. Finally, the rates of crack growth are presented for various stainless steels, mainly austenitic. The study overall aim is an investigation of the cracking in the 900 MWe primary pump thermal barriers and shafts

  19. DETERMINATION OF THE SPECIFIC GROWTH RATE ON ...

    African Journals Online (AJOL)

    Sewage generation is one of the dense problems Nigerians encounter on daily bases, mostly at the urbanized area where factories and industries are located. This paper is aimed at determining the specific growth rate “K” of biological activities on cassava wastewater during degradation using Michaelis-Menten Equation.

  20. Size-dependent standard deviation for growth rates: empirical results and theoretical modeling.

    Science.gov (United States)

    Podobnik, Boris; Horvatic, Davor; Pammolli, Fabio; Wang, Fengzhong; Stanley, H Eugene; Grosse, I

    2008-05-01

    We study annual logarithmic growth rates R of various economic variables such as exports, imports, and foreign debt. For each of these variables we find that the distributions of R can be approximated by double exponential (Laplace) distributions in the central parts and power-law distributions in the tails. For each of these variables we further find a power-law dependence of the standard deviation sigma(R) on the average size of the economic variable with a scaling exponent surprisingly close to that found for the gross domestic product (GDP) [Phys. Rev. Lett. 81, 3275 (1998)]. By analyzing annual logarithmic growth rates R of wages of 161 different occupations, we find a power-law dependence of the standard deviation sigma(R) on the average value of the wages with a scaling exponent beta approximately 0.14 close to those found for the growth of exports, imports, debt, and the growth of the GDP. In contrast to these findings, we observe for payroll data collected from 50 states of the USA that the standard deviation sigma(R) of the annual logarithmic growth rate R increases monotonically with the average value of payroll. However, also in this case we observe a power-law dependence of sigma(R) on the average payroll with a scaling exponent beta approximately -0.08 . Based on these observations we propose a stochastic process for multiple cross-correlated variables where for each variable (i) the distribution of logarithmic growth rates decays exponentially in the central part, (ii) the distribution of the logarithmic growth rate decays algebraically in the far tails, and (iii) the standard deviation of the logarithmic growth rate depends algebraically on the average size of the stochastic variable.

  1. Size-dependent standard deviation for growth rates: Empirical results and theoretical modeling

    Science.gov (United States)

    Podobnik, Boris; Horvatic, Davor; Pammolli, Fabio; Wang, Fengzhong; Stanley, H. Eugene; Grosse, I.

    2008-05-01

    We study annual logarithmic growth rates R of various economic variables such as exports, imports, and foreign debt. For each of these variables we find that the distributions of R can be approximated by double exponential (Laplace) distributions in the central parts and power-law distributions in the tails. For each of these variables we further find a power-law dependence of the standard deviation σ(R) on the average size of the economic variable with a scaling exponent surprisingly close to that found for the gross domestic product (GDP) [Phys. Rev. Lett. 81, 3275 (1998)]. By analyzing annual logarithmic growth rates R of wages of 161 different occupations, we find a power-law dependence of the standard deviation σ(R) on the average value of the wages with a scaling exponent β≈0.14 close to those found for the growth of exports, imports, debt, and the growth of the GDP. In contrast to these findings, we observe for payroll data collected from 50 states of the USA that the standard deviation σ(R) of the annual logarithmic growth rate R increases monotonically with the average value of payroll. However, also in this case we observe a power-law dependence of σ(R) on the average payroll with a scaling exponent β≈-0.08 . Based on these observations we propose a stochastic process for multiple cross-correlated variables where for each variable (i) the distribution of logarithmic growth rates decays exponentially in the central part, (ii) the distribution of the logarithmic growth rate decays algebraically in the far tails, and (iii) the standard deviation of the logarithmic growth rate depends algebraically on the average size of the stochastic variable.

  2. Mathematical model for predicting molecular-beam epitaxy growth rates for wafer production

    International Nuclear Information System (INIS)

    Shi, B.Q.

    2003-01-01

    An analytical mathematical model for predicting molecular-beam epitaxy (MBE) growth rates is reported. The mathematical model solves the mass-conservation equation for liquid sources in conical crucibles and predicts the growth rate by taking into account the effect of growth source depletion on the growth rate. Assumptions made for deducing the analytical model are discussed. The model derived contains only one unknown parameter, the value of which can be determined by using data readily available to MBE growers. Procedures are outlined for implementing the model in MBE production of III-V compound semiconductor device wafers. Results from use of the model to obtain targeted layer compositions and thickness of InP-based heterojunction bipolar transistor wafers are presented

  3. Parametric analysis of fatigue crack growth

    International Nuclear Information System (INIS)

    Carden, A.E.

    1975-01-01

    The effect of temperature and frequency on fatigue crack growth were empirically observed and treated as a coefficient on a stress intensity factor term. The stress intensity factor term is a function of Ksub(max), Ksub(min) (or stress ratio) and a threshold K term. The apparent threshold values were selected in order to linearize the data. At 1000 0 F a constant da/dt (creep crack growth rate) is approached for cycle periods approaching 2000 s indicating a limiting and linear-inverse frequency effect. (author)

  4. Hartman-Wintner growth results for sublinear functional differential equations

    Directory of Open Access Journals (Sweden)

    John A. D. Appleby

    2017-01-01

    Full Text Available This article determines the rate of growth to infinity of scalar autonomous nonlinear functional and Volterra differential equations. In these equations, the right-hand side is a positive continuous linear functional of f(x. We assume f grows sublinearly, leading to subexponential growth in the solutions. The main results show that the solution of the functional differential equations are asymptotic to that of an auxiliary autonomous ordinary differential equation with right-hand side proportional to f. This happens provided f grows more slowly than l(x=x/log(x. The linear-logarithmic growth rate is also shown to be critical: if f grows more rapidly than l, the ODE dominates the FDE; if f is asymptotic to a constant multiple of l, the FDE and ODE grow at the same rate, modulo a constant non-unit factor; if f grows more slowly than l, the ODE and FDE grow at exactly the same rate. A partial converse of the last result is also proven. In the case when the growth rate is slower than that of the ODE, sharp bounds on the growth rate are determined. The Volterra and finite memory equations can have differing asymptotic behaviour and we explore the source of these differences.

  5. How does political instability affect economic growth?

    OpenAIRE

    Aisen, Ari; Veiga, Francisco José

    2011-01-01

    The purpose of this paper is to empirically determine the effects of political instability on economic growth. Using the system-GMM estimator for linear dynamic panel data models on a sample covering up to 169 countries, and 5-year periods from 1960 to 2004, we find that higher degrees of political instability are associated with lower growth rates of GDP per capita. Regarding the channels of transmission, we find that political instability adversely affects growth by lowering the rates of pr...

  6. Herdabilidades de parâmetros de curvas de crescimento não-lineares em zebuínos, no estado de Pernambuco Heritabilities of nonlinear growth curve parameters in zebu breeds, in Pernambuco State, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Kleber Régis Santoro

    2005-12-01

    Full Text Available Objetivou-se estimar parâmetros genéticos e fenotípicos de curvas de crescimento de modelos não-lineares. Foram analisados dados de pesagem constantes no banco de dados de Controle de Desenvolvimento Ponderal da Associação Brasileira de Criadores de Zebu (ABCZ, referentes a 24.028 animais Zebu, nascidos entre 1960 e 2000, das raças Guzerá, Nelore e Nelore Mocho. As pesagens ocorreram ao nascimento e em intervalos de 90 dias até dois anos de idade. Os seguintes modelos não-lineares foram utilizados na análise dos dados de peso-idade: Brody, Gompertz, Logístico, von Bertalanffy e Richards. Os efeitos fixos estudados no modelo misto foram sexo, rebanho, ano e mês de nascimento e regime de criação. As herdabilidades para os parâmetros foram de baixa a alta magnitude, em geral, para todos os modelos. As correlações genéticas entre peso assintótico e taxa de maturidade e entre peso assintótico e velocidade de crescimento foram negativas, enquanto aquelas entre taxa de maturidade e velocidade de crescimento foram positivas. As correlações fenotípicas foram negativas entre peso assintótico e taxa de crescimento e entre peso assintótico e velocidade de crescimento e positivas entre taxa e velocidade de crescimento. Encontrou-se variabilidade possível de ser explorada em um programa de melhoramento genético, especialmente para a raça Nelore, que apresentou amostra de dados e resultados mais consistentes.Weight records of 24.028 zebu animals from Guzerá, Nelore, and Polled Nelore breeds available from Brazilian Association of Zebu Breeders (ABCZ database were used to estimate heritabilities of growth curve parameters. Non-linear Brody, Gompertz, Logistic, Mitscherlich, von Bertalanffy, Richards, and Double Logistic models including sex, farm, year of birth, month of birth, raising system, and interaction sex*raising system as fixed effects and sire and dam, as random effects were adjusted using weight-age records of animals

  7. Calcite growth-rate inhibition by fulvic acid and magnesium ion—Possible influence on biogenic calcite formation

    Science.gov (United States)

    Reddy, Michael M.

    2012-01-01

    Increases in ocean surface water dissolved carbon dioxide (CO2) concentrations retard biocalcification by reducing calcite supersaturation (Ωc). Reduced calcification rates may influence growth-rate dependent magnesium ion (Mg) incorporation into biogenic calcite modifying the use of calcifying organisms as paleoclimate proxies. Fulvic acid (FA) at biocalcification sites may further reduce calcification rates. Calcite growth-rate inhibition by FA and Mg, two common constituents of seawater and soil water involved in the formation of biogenic calcite, was measured separately and in combination under identical, highly reproducible experimental conditions. Calcite growth rates (pH=8.5 and Ωc=4.5) are reduced by FA (0.5 mg/L) to 47% and by Mg (10−4 M) to 38%, compared to control experiments containing no added growth-rate inhibitor. Humic acid (HA) is twice as effective a calcite growth-rate inhibitor as FA. Calcite growth rate in the presence of both FA (0.5 mg/L) and Mg (10−4 M) is reduced to 5% of the control rate. Mg inhibits calcite growth rates by substitution for calcium ion at the growth site. In contrast, FA inhibits calcite growth rates by binding multiple carboxylate groups on the calcite surface. FA and Mg together have an increased affinity for the calcite growth sites reducing calcite growth rates.

  8. Coordinated Changes in Mutation and Growth Rates Induced by Genome Reduction

    Directory of Open Access Journals (Sweden)

    Issei Nishimura

    2017-07-01

    Full Text Available Genome size is determined during evolution, but it can also be altered by genetic engineering in laboratories. The systematic characterization of reduced genomes provides valuable insights into the cellular properties that are quantitatively described by the global parameters related to the dynamics of growth and mutation. In the present study, we analyzed a small collection of W3110 Escherichia coli derivatives containing either the wild-type genome or reduced genomes of various lengths to examine whether the mutation rate, a global parameter representing genomic plasticity, was affected by genome reduction. We found that the mutation rates of these cells increased with genome reduction. The correlation between genome length and mutation rate, which has been reported for the evolution of bacteria, was also identified, intriguingly, for genome reduction. Gene function enrichment analysis indicated that the deletion of many of the genes encoding membrane and transport proteins play a role in the mutation rate changes mediated by genome reduction. Furthermore, the increase in the mutation rate with genome reduction was highly associated with a decrease in the growth rate in a nutrition-dependent manner; thus, poorer media showed a larger change that was of higher significance. This negative correlation was strongly supported by experimental evidence that the serial transfer of the reduced genome improved the growth rate and reduced the mutation rate to a large extent. Taken together, the global parameters corresponding to the genome, growth, and mutation showed a coordinated relationship, which might be an essential working principle for balancing the cellular dynamics appropriate to the environment.

  9. Non-linear coupling of drift modes in a quadrupole

    International Nuclear Information System (INIS)

    Elliott, J.A.; Sandeman, J.C.; Tessema, G.Y.

    1990-01-01

    We report continuing experimental studies of non-linear interactions of drift waves, with direct evidence of a growth saturation mechanism by transfer of energy to lower frequency modes. Wave launching experiments show that the decay rate of drift waves can be strongly amplitude dependent. (author) 9 refs., 5 figs

  10. Diagnostic Accuracy of Growth Rate in Differentiating Etiologies of Short Stature in Children

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Alaei

    2016-08-01

    Full Text Available Background  Short stature is a manifestation of a wide variety of conditions that some of which may be amenable to timely treatment and a suboptimal growth rate may be an early marker pointing to the cause of growth retardation. This study was conducted to evaluate the diagnostic utility of growth rate in differential diagnosis of children with short stature. Materials and Methods All children between the ages of 2 and 18 years who visited in pediatric endocrinology clinic in a five years period were recruited in a prospective cohort study. Children with standing height Results One hundred forty three patients fulfilled the inclusion criteria. Mean follow up period was 14.4±10.9 months. Etiologies of short stature were: constitutional growth delay (CGD 46.9%, familial short stature (FSS 28.7%, hypothyroidism 4.2%, growth hormone deficiency (GHD 4.2% and miscellaneous causes in 16% of patients.  Mean Z- score for children with constitutional growth delay was -2.3±0.69, in familial short stature was -2.3±0.65 and for other condition was -2.7±1.49. There was a meaningful statistical correlation between growth rate and etiology of short stature (P0.05. Conclusion There was significant difference in growth rate between children with constitutional growth delay and familial short stature in comparing to short stature due to endocrine problem and other etiologies. Assessment of growth rate has some utility in diagnosing the etiology of short stature.

  11. Daily changes in temperature, not the circadian clock, regulate growth rate in Brachypodium distachyon.

    Directory of Open Access Journals (Sweden)

    Dominick A Matos

    Full Text Available Plant growth is commonly regulated by external cues such as light, temperature, water availability, and internal cues generated by the circadian clock. Changes in the rate of growth within the course of a day have been observed in the leaves, stems, and roots of numerous species. However, the relative impact of the circadian clock on the growth of grasses has not been thoroughly characterized. We examined the influence of diurnal temperature and light changes, and that of the circadian clock on leaf length growth patterns in Brachypodium distachyon using high-resolution time-lapse imaging. Pronounced changes in growth rate were observed under combined photocyles and thermocycles or with thermocycles alone. A considerably more rapid growth rate was observed at 28°C than 12°C, irrespective of the presence or absence of light. In spite of clear circadian clock regulated gene expression, plants exhibited no change in growth rate under conditions of constant light and temperature, and little or no effect under photocycles alone. Therefore, temperature appears to be the primary cue influencing observed oscillations in growth rate and not the circadian clock or photoreceptor activity. Furthermore, the size of the leaf meristem and final cell length did not change in response to changes in temperature. Therefore, the nearly five-fold difference in growth rate observed across thermocycles can be attributed to proportionate changes in the rate of cell division and expansion. A better understanding of the growth cues in B. distachyon will further our ability to model metabolism and biomass accumulation in grasses.

  12. Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field

    International Nuclear Information System (INIS)

    Kheiri, Golshad; Esmaeilzadeh, Mahdi

    2013-01-01

    A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread

  13. Spatial distribution of soda straws growth rates of the Coufin Cave (Vercors, France

    Directory of Open Access Journals (Sweden)

    Perrette Yves

    2010-07-01

    Full Text Available The Choranche Cave system (Vercors, France is an excellent locality for measuring the growth rates of large numbers soda straws. This is especially the case for the Coufin Cave, as enlargement of the cave entrance in 1875 led to a change in stalactite color from brown to white, thus providing a reliable chronomarker. The date of this brown-to-white calcite transition has been confirmed by lamina counting. We measured and georeferenced the growth-lengths of 306 soda straws in a 1m2 area of the roof of the Coufin Cave entrance chamber. Because of the very slow and sometimes inexistent water feeding of those stalactites, hydrochemistry analysis were not achieved and drop rate effect on growth were neglected; this study is based on a geomorphological and geostatistical work. By measuring a large number of soda straws in a very small area for which most of the parameters affecting stalactite growth could be considered uniform, and because flow rates are very slow (frequencies are always superior to 1 drop per half hour, we could ascribe differences in growth rates to variations in the global increase of water flow through the unsaturated matrix. Statistical and geostatistical analyses of the measurements showed that this set of similarly shaped stalactites actually consisted of three Gaussian populations with different mean growth rates: fast growth rate (FGR- mean of 0.92 mm.y-1, medium growth rate (MGR- mean of 0.47 mm.y-1 and low growth rate (LGR- 0.09 mm.y-1. Plotting the lengths and spatial distribution of the 20 longest FGR soda straws revealed that there is a rough pattern to the water flow through the cave roof. Even if no direction is statisticaly different from others, the observed directional pattern is consistent with local and regional tectonic observations. Plots of the spatial distribution of the soda straws show that FGR soda straws follow lines of regional geological stress, whereas MGR and LGR soda straws are more dispersed.

  14. Variability in growth rates of larval haddock in the northern North Sea

    DEFF Research Database (Denmark)

    Gallego, A.; Heath, M.R.; Basford, D.J.

    1999-01-01

    of the spring plankton production bloom, and a likely explanation for the absence of environmental effects on larval growth was high food availability and larval feeding rates. Nevertheless, differences in growth were observed between cohorts, with larvae hatched later in the spring displaying higher growth...... at age than those hatched earlier. Particle-tracking modelling suggested that differences in temperature history between cohorts, on their own or compounded by a potential interaction between temperature and the development of plankton production, may explain the higher growth rate of the larvae hatched...

  15. Gross domestic product growth rates as confined Lévy flights: Towards a unifying theory of economic growth rate fluctuations

    Science.gov (United States)

    Lera, Sandro Claudio; Sornette, Didier

    2018-01-01

    A model that combines economic growth rate fluctuations at the microscopic and macroscopic levels is presented. At the microscopic level, firms are growing at different rates while also being exposed to idiosyncratic shocks at the firm and sector levels. We describe such fluctuations as independent Lévy-stable fluctuations, varying over multiple orders of magnitude. These fluctuations are aggregated and measured at the macroscopic level in averaged economic output quantities such as GDP. A fundamental question is thereby to what extent individual firm size fluctuations can have a noticeable impact on the overall economy. We argue that this question can be answered by considering the Lévy fluctuations as embedded in a steep confining potential well, ensuring nonlinear mean-reversal behavior, without having to rely on microscopic details of the system. The steepness of the potential well directly controls the extent to which idiosyncratic shocks to firms and sectors are damped at the level of the economy. Additionally, the theory naturally accounts for business cycles, represented in terms of a bimodal economic output distribution and thus connects two so far unrelated fields in economics. By analyzing 200 years of U.S. gross domestic product growth rates, we find that the model is in good agreement with the data.

  16. Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa.

    Science.gov (United States)

    Healey, Adam L; Lee, David J; Lupoi, Jason S; Papa, Gabriella; Guenther, Joel M; Corno, Luca; Adani, Fabrizio; Singh, Seema; Simmons, Blake A; Henry, Robert J

    2016-01-01

    In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7-21.3%) among parental and hybrid populations, whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28-38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase), and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%, respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively), with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.

  17. Evaluation of relationships between growth rate, tree size, lignocellulose composition and enzymatic saccharification in interspecific Corymbia hybrids and parental taxa.

    Directory of Open Access Journals (Sweden)

    Adam L Healey

    2016-11-01

    Full Text Available In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF and parental species C. torelliana (CT and C. citriodora subspecies variegata (CCV and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7-21.3% among parental and hybrid populations, whereas glucan content was clearly distinguished within CCV (52% and HF148 (60% as compared to other populations (28-38%. Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH (+0.12% per cm DBH increase, and glucan and xylan typically decreasing per DBH cm increase (-0.7% and -0.3%, respectively. Polysaccharide content within CCV and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental CT and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively, with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%. Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.

  18. Influence of corruption on economic growth rate and foreign investment

    Science.gov (United States)

    Podobnik, Boris; Shao, Jia; Njavro, Djuro; Ivanov, Plamen Ch.; Stanley, H. E.

    2008-06-01

    We analyze the dependence of the Gross Domestic Product ( GDP) per capita growth rates on changes in the Corruption Perceptions Index ( CPI). For the period 1999 2004 for all countries in the world, we find on average that an increase of CPI by one unit leads to an increase of the annual GDP per capita growth rate by 1.7%. By regressing only the European countries with transition economies, we find that an increase of CPI by one unit generates an increase of the annual GDP per capita growth rate by 2.4%. We also analyze the relation between foreign direct investments received by different countries and CPI, and we find a statistically significant power-law functional dependence between foreign direct investment per capita and the country corruption level measured by the CPI. We introduce a new measure to quantify the relative corruption between countries based on their respective wealth as measured by GDP per capita.

  19. International Trade and Economic Growth in the Polish Economy

    Directory of Open Access Journals (Sweden)

    Henryk Gurgul

    2010-01-01

    Full Text Available The paper presents the results of examinations of linear and nonlinear causalities performed for international trade involving the Polish economy and its economic growth. In order to infer the impact of the world crisis on the Polish economy, two samples have been studied (containing quarterly data – a full sample (Q1 1996–Q3 2009 and pre-crisis sample (Q1 1996–Q3 2008. The results of linear causality tests support the existence of feedback between the growth rate of exports and growth in gross domestic product (GDP irrespectively of the time period chosen. For both the samples examined, no direct causal links between the growth rates of GDP and imports were detected. One can only suppose the existence of indirect links before the crisis. Bidirectional causality was found for growth rates of exports and imports only for the pre-crisis sample. Some weak evidence of a causal link running from the growth rate of imports to the growth rate of exports was also found for the period that covers the crisis, which may be interpreted as a confirmation of the fact that growth in imports also precedes growth in exports in bullish periods. It results from our computations that, at the time of the financial crisis of 2008, the main factor that caused Polish GDP growth to remain positive was domestic demand. The results of nonlinear causality analysis provided only weak evidence for causality running from GDP to exports, from GDP to imports and from imports to exports. (original abstract

  20. CK2 activity is modulated by growth rate in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Tripodi, Farida; Cirulli, Claudia; Reghellin, Veronica; Marin, Oriano; Brambilla, Luca; Schiappelli, Maria Patrizia; Porro, Danilo; Vanoni, Marco; Alberghina, Lilia; Coccetti, Paola

    2010-01-01

    Research highlights: → CK2 subunits are nuclear both in glucose and in ethanol growing yeast cells. → CK2 activity is modulated in S. cerevisiae. → CK2 activity is higher in conditions supporting higher growth rates. → V max is higher in faster growing cells, while K m is not affected. -- Abstract: CK2 is a highly conserved protein kinase controlling different cellular processes. It shows a higher activity in proliferating mammalian cells, in various types of cancer cell lines and tumors. The findings presented herein provide the first evidence of an in vivo modulation of CK2 activity, dependent on growth rate, in Saccharomyces cerevisiae. In fact, CK2 activity, assayed on nuclear extracts, is shown to increase in exponential growing batch cultures at faster growth rate, while localization of catalytic and regulatory subunits is not nutritionally modulated. Differences in intracellular CK2 activity of glucose- and ethanol-grown cells appear to depend on both increase in molecule number and k cat . Also in chemostat cultures nuclear CK2 activity is higher in faster growing cells providing the first unequivocal demonstration that growth rate itself can affect CK2 activity in a eukaryotic organism.

  1. Tax Rates, Tax Evasion, and Growth in a Multi-period Economy

    OpenAIRE

    Jordi Caballé; Judith Panadés

    2007-01-01

    We extend the basic tax evasion model to a multi-period economy exhibiting sustained growth. When individuals conceal part of their true income from the tax authority, they face the risk of being audited and hence of paying the corresponding fine. Both taxes and fines determine individual saving and the rate of capital accumulation. We show that, if the penalty imposed on tax evaders is proportional to the amount of evaded taxes, then the growth rate is decreasing in the tax rate. However, th...

  2. Elevated atmospheric CO2 increases microbial growth rates and enzymes activity in soil

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Dorodnikov, Maxim; Kuzyakov, Yakov

    2010-05-01

    Increasing the belowground translocation of assimilated carbon by plants grown under elevated CO2 can cause a shift in the structure and activity of the microbial community responsible for the turnover of organic matter in soil. We investigated the long-term effect of elevated CO2 in the atmosphere on microbial biomass and specific growth rates in root-free and rhizosphere soil. The experiments were conducted under two free air carbon dioxide enrichment (FACE) systems: in Hohenheim and Braunschweig, as well as in the intensively managed forest mesocosm of the Biosphere 2 Laboratory (B2L) in Oracle, AZ. Specific microbial growth rates (μ) were determined using the substrate-induced respiration response after glucose and/or yeast extract addition to the soil. We evaluated the effect of elevated CO2 on b-glucosidase, chitinase, phosphatase, and sulfatase to estimate the potential enzyme activity after soil amendment with glucose and nutrients. For B2L and both FACE systems, up to 58% higher μ were observed under elevated vs. ambient CO2, depending on site, plant species and N fertilization. The μ-values increased linearly with atmospheric CO2 concentration at all three sites. The effect of elevated CO2 on rhizosphere microorganisms was plant dependent and increased for: Brassica napus=Triticum aestivumyeast extract then for those growing on glucose, i.e. the effect of elevated CO2 was smoothed on rich vs. simple substrate. So, the r/K strategies ratio can be better revealed by studying growth on simple (glucose) than on rich substrate mixtures (yeast extract). After adding glucose, enzyme activities under elevated CO2 were 1.2-1.9-fold higher than under ambient CO2. This indicates the increased activity of microorganisms, which leads to accelerated C turnover in soil under elevated CO2. Our results clearly showed that the functional characteristics of the soil microbial community (i.e. specific growth rates and enzymes activity) rather than total microbial biomass

  3. Growth limitation of Lemna minor due to high plant density

    NARCIS (Netherlands)

    Driever, S.M.; Nes, van E.H.; Roijackers, R.M.M.

    2005-01-01

    The effect of high population densities on the growth rate of Lemna minor (L.) was studied under laboratory conditions at 23°C in a medium with sufficient nutrients. At high population densities, we found a non-linear decreasing growth rate with increasing L. minor density. Above a L. minor biomass

  4. [Growth rate and bone maturation in celiac disease (author's transl)].

    Science.gov (United States)

    Martínez Sopena, M J; Calvo Romero, M C; Bedate Calderón, P; Alonso Franch, M; Sánchez Villares, E

    1978-05-01

    The growth and bone maturation of 43 celiac patients were analyzed. A significant correlation between gluten intake and growth rate was found. The authors suggest this is a good parameter to advise the best moment to make the control biopsie and the provocation test.

  5. Growth, exchange rates and trade in Brazil: a structuralist post-Keynesian approach

    Directory of Open Access Journals (Sweden)

    Nelson H. Barbosa Filho

    2004-01-01

    Full Text Available This paper presents a structuralist post-Keynesian analysis of trade adjustment in Brazil. Based on the concept of the balance-of-payments (BoP constraint on growth, the paper investigates the relationship between income growth and real-exchange-rate devaluation necessary to adjust trade to a foreign-exchange constraint. The main result is that, with price-inelastic and income-elastic imports and based on its trade structure in 2002, Brazil may have to compensate an additional 1% of income growth with approximately 7% of real-exchange-rate devaluation in order to keep its trade balance stable in relation to GDP in the near future. Moreover, the trade parameters of Brazil seem to be unfavorable to growth with stable trade, that is, even moderate rates of GDP expansion lead to a substantial increase of imports and, therefore, require an also substantial devaluation of the real exchange rate to avoid a deterioration of the trade balance.

  6. Growth, exchange rates and trade in Brazil: a structuralist post Keynesian approach

    Directory of Open Access Journals (Sweden)

    Nelson H. Barbosa Filho

    2009-06-01

    Full Text Available This paper presents a structuralist post-Keynesian analysis of trade adjustment in Brazil. Based on the concept of the balance-of-payments (BoP constraint on growth, the paper investigates the relationship between income growth and real-exchange-rate devaluation necessary to adjust trade to a foreign-exchange constraint. The main result is that, with price-inelastic and income-elastic imports and based on its trade structure in 2002, Brazil may have to compensate an additional 1% of income growth with approximately 7% of real-exchange-rate devaluation in order to keep its trade balance stable in relation to GDP in the near future. Moreover, the trade parameters of Brazil seem to be unfavorable to growth with stable trade, that is, even moderate rates of GDP expansion lead to a substantial increase of imports and, therefore, require an also substantial devaluation of the real exchange rate to avoid a deterioration of the trade balance.

  7. Non-linearities in Theory-of-Mind Development.

    Science.gov (United States)

    Blijd-Hoogewys, Els M A; van Geert, Paul L C

    2016-01-01

    Research on Theory-of-Mind (ToM) has mainly focused on ages of core ToM development. This article follows a quantitative approach focusing on the level of ToM understanding on a measurement scale, the ToM Storybooks, in 324 typically developing children between 3 and 11 years of age. It deals with the eventual occurrence of developmental non-linearities in ToM functioning, using smoothing techniques, dynamic growth model building and additional indicators, namely moving skewness, moving growth rate changes and moving variability. The ToM sum-scores showed an overall developmental trend that leveled off toward the age of 10 years. Within this overall trend two non-linearities in the group-based change pattern were found: a plateau at the age of around 56 months and a dip at the age of 72-78 months. These temporary regressions in ToM sum-score were accompanied by a decrease in growth rate and variability, and a change in skewness of the ToM data, all suggesting a developmental shift in ToM understanding. The temporary decreases also occurred in the different ToM sub-scores and most clearly so in the core ToM component of beliefs. It was also found that girls had an earlier growth spurt than boys and that the underlying developmental path was more salient in girls than in boys. The consequences of these findings are discussed from various theoretical points of view, with an emphasis on a dynamic systems interpretation of the underlying developmental paths.

  8. Introduction to linear systems of differential equations

    CERN Document Server

    Adrianova, L Ya

    1995-01-01

    The theory of linear systems of differential equations is one of the cornerstones of the whole theory of differential equations. At its root is the concept of the Lyapunov characteristic exponent. In this book, Adrianova presents introductory material and further detailed discussions of Lyapunov exponents. She also discusses the structure of the space of solutions of linear systems. Classes of linear systems examined are from the narrowest to widest: 1)�autonomous, 2)�periodic, 3)�reducible to autonomous, 4)�nearly reducible to autonomous, 5)�regular. In addition, Adrianova considers the following: stability of linear systems and the influence of perturbations of the coefficients on the stability the criteria of uniform stability and of uniform asymptotic stability in terms of properties of the solutions several estimates of the growth rate of solutions of a linear system in terms of its coefficients How perturbations of the coefficients change all the elements of the spectrum of the system is defin...

  9. A Minimalistic Resource Allocation Model to Explain Ubiquitous Increase in Protein Expression with Growth Rate.

    Directory of Open Access Journals (Sweden)

    Uri Barenholz

    Full Text Available Most proteins show changes in level across growth conditions. Many of these changes seem to be coordinated with the specific growth rate rather than the growth environment or the protein function. Although cellular growth rates, gene expression levels and gene regulation have been at the center of biological research for decades, there are only a few models giving a base line prediction of the dependence of the proteome fraction occupied by a gene with the specific growth rate. We present a simple model that predicts a widely coordinated increase in the fraction of many proteins out of the proteome, proportionally with the growth rate. The model reveals how passive redistribution of resources, due to active regulation of only a few proteins, can have proteome wide effects that are quantitatively predictable. Our model provides a potential explanation for why and how such a coordinated response of a large fraction of the proteome to the specific growth rate arises under different environmental conditions. The simplicity of our model can also be useful by serving as a baseline null hypothesis in the search for active regulation. We exemplify the usage of the model by analyzing the relationship between growth rate and proteome composition for the model microorganism E.coli as reflected in recent proteomics data sets spanning various growth conditions. We find that the fraction out of the proteome of a large number of proteins, and from different cellular processes, increases proportionally with the growth rate. Notably, ribosomal proteins, which have been previously reported to increase in fraction with growth rate, are only a small part of this group of proteins. We suggest that, although the fractions of many proteins change with the growth rate, such changes may be partially driven by a global effect, not necessarily requiring specific cellular control mechanisms.

  10. On convergence rates for iteratively regularized procedures with linear penalty terms

    International Nuclear Information System (INIS)

    Smirnova, Alexandra

    2012-01-01

    The impact of this paper is twofold. First, we study convergence rates of the iteratively regularized Gauss–Newton (IRGN) algorithm with a linear penalty term under a generalized source assumption and show how the regularizing properties of new iterations depend on the solution smoothness. Secondly, we introduce an adaptive IRGN procedure, which is investigated under a relaxed smoothness condition. The introduction and analysis of a more general penalty term are of great importance since, apart from bringing stability to the numerical scheme designed for solving a large class of applied inverse problems, it allows us to incorporate various types of a priori information available on the model. Both a priori and a posteriori stopping rules are investigated. For the a priori stopping rule, optimal convergence rates are derived. A numerical example illustrating convergence rates is considered. (paper)

  11. Evaluation of Mycelium Growth Rate and Yield of White Button Mushroom Isolates (Agaricus bisporus in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Ahmadi Lahijani

    2017-10-01

    Full Text Available Introduction: Among edible mushrooms, white button mushroom is the most cultivated one around the world. Mono-spores diversity in terms of growth rate, colony type, yield and etc. is used for intra strain genetic improvement. High yielding isolates with filamentous mycelium type are screened and used for spawn production (Farsi and Gordan, 2002. Success in mushroom production largely depends on the quality of spawn produced in sterile conditions (Sanchez, 2010. Farsi and Gordan, (2004 reported that colony shape and mycelium growth type are very important factors in screening isolates in terms of mycelium growth rate and yield. To screen isolates based on their mycelium growth, solid media are among the most suitable ones (Griffin, 1994. In a study conducted to evaluate mycelium growth rate of six Morchella species on different media, PDA and MEA were known as the best ones (Kalmis and Kalyoncu, 2008. The present study was conducted in order to evaluate mycelium growth rate and yield of white button mushroom isolates in solid medium, spawn and compost media. Materials and methods: Eighteen isolates of white button mushroom were compared on PDA (Potato Dextrose Agar, CYM (Complete Yeast Medium, spawn and compost media based on mycelium growth rate, type and class growth and yield at the mushroom research center of Faculty of Agriculture, Ferdowsi University of Mashhad, in 2014. A piece of mycelium of each isolate was placed in the center of each petri dish and was kept in 23±1°C, and the radial growth rate of mycelium was measured as two perpendicular diameters in three consecutive weeks. Mycelium growth rate on spawn and compost media was measured based on the percentage of surface coverage during the 15 consecutive days. Yield of each isolate was measured by daily harvesting of mushrooms during 35 days of experiment. Analysis of variance and means comparison of the variables were carried out using SAS software. Means analysis was performed

  12. Stunted at 10 Years. Linear Growth Trajectories and Stunting from Birth to Pre-Adolescence in a Rural Bangladeshi Cohort.

    Directory of Open Access Journals (Sweden)

    Pernilla Svefors

    Full Text Available Few studies in low-income settings analyse linear growth trajectories from foetal life to pre-adolescence. The aim of this study is to describe linear growth and stunting from birth to 10 years in rural Bangladesh and to analyse whether maternal and environmental determinants at conception are associated with linear growth throughout childhood and stunting at 10 years.Pregnant women participating in the MINIMat trial were identified in early pregnancy and a birth cohort (n = 1054 was followed with 19 growth measurements from birth to 10 years. Analyses of baseline predictors and mean height-for-age Z-scores (HAZ over time were modelled using GLMM. Logistic regression analysis was used to investigate the associations between baseline predictors and stunting (HAZ<-2 at 10 years. HAZ decreased to 2 years, followed by an increase up to 10 years, while the average height-for-age difference in cm (HAD to the WHO reference median continued to increase up to 10 years. Prevalence of stunting was highest at 2 years (50% decreasing to 29% at 10 years. Maternal height, maternal educational level and season of conception were all independent predictors of HAZ from birth to pre-adolescence (p<0.001 and stunting at 10 years. The highest probability to be stunted at 10 years was for children born by short mothers (<147.5 cm (ORadj 2.93, 95% CI: 2.06-4.20, mothers with no education (ORadj 1.74, 95% CI 1.17-2.81 or those conceived in the pre-monsoon season (ORadj 1.94, 95% CI 1.37-2.77.Height growth trajectories and prevalence of stunting in pre-adolescence showed strong intergenerational associations, social differentials, and environmental influence from foetal life. Targeting women before and during pregnancy is needed for the prevention of impaired child growth.

  13. Last Five Years Pakistan Economic Growth Rate GDP And Its Comparison With China India And Bangladesh

    Directory of Open Access Journals (Sweden)

    Abdul Rehman

    2015-01-01

    Full Text Available Abstract This paper formulates and reviews Pakistans last five years economic growth rate and its comparison with the growth rate of China India and Bangladesh. As growth rate the amount of increment of a specific variable has gained within a specific period of time and context. In fact economic growth rate provides general direction and magnitude of growth for overall economy.

  14. Capital accumulation, structural change and real exchange rate in a Keynesian-Structuralist growth model

    Directory of Open Access Journals (Sweden)

    Oreiro José Luis

    2015-01-01

    Full Text Available The aim of this paper is to show at theoretical level that maintaining a competitive real exchange rate positively affects the economic growth of developing countries by means of a Keynesian-Structuralist model that combines elements of Kaleckian growth models with the balance of payments constrained growth models pioneered developed by Thirlwall. In this setting, the level of real exchange rate is capable, due to its effect over capital accumulation, to induce a structural change in the economy, making endogenous income elasticities of exports and imports. For reasonable parameter values it is shown that in steady-state growth there is two long-run equilibrium values for real exchange rate, one that corresponds to an under-valued currency and another that corresponds to an over-valued currency. If monetary authorities run exchange rate policy in order to target a competitive level for real exchange rate, than under-valued equilibrium is stable and the economy will show a high growth rate in the long-run.

  15. Variation in relative growth rate and growth traits in wild and cultivated Capsicum accessions grown under different temperatures

    NARCIS (Netherlands)

    Swart, de E.A.M.; Marcelis, L.F.M.; Voorrips, R.E.

    2006-01-01

    Differences in environmental conditions are known to influence plant growth and growth-related traits. The aim of this study was to identify the variation in relative growth rate (RGR), and its underlying physiological and morphological traits, in a group of ten wild and cultivated Capsicum

  16. Optimal tax rate and economic growth. Evidence from Nigeria and South Africa

    Directory of Open Access Journals (Sweden)

    Olufemi Muibi SAIBU

    2015-05-01

    Full Text Available The recent economic crisis had made developing countries to look inward for financial resources to finance development. The readily alternative is the tax revenues however, the possible adverse direct and indirect effects of tax on productivity and work efforts as well as on aggregate consumption had make some African countries (especially Nigeria and South Africa reluctant in implementing far reaching tax policy reform. This paper examines optimal tax burden and real output growth Nigeria and South Africa, two of the top four economies in Africa. The paper empirically determined what should be the optimal tax rate for Nigeria and South Africa-the two leading economies in Africa. The paper found that nonlinearity hypothesis in the effects of tax in the case of South Africa is rejected while a significant nonlinear relationship is found in the case of Nigeria. The results suggest that the growth-maximizing tax rate is about 15% of per capita GDP for South Africa and 30% for Nigeria. At that tax rate, the economic growth rate would be around 6% and 8% instead of the actual mean growth rate of 2.84% and 4.51% for South Africa and Nigeria respectively. The paper concluded the current tax burden in the two countries may be sub-optimal and may hurt long term sustainable growth process in the two countries

  17. Rheokinetics and effect of shear rate on the kinetics of linear polyurethane formation

    NARCIS (Netherlands)

    Navarchian, AH; Picchioni, F; Janssen, LPBM

    In this article, the rheokinetics of polyurethane formation and the influence of shear rate on its kinetics have been studied. Two different linear polyurethane systems with 0% and 100% hard segments are examined in a cone and plate rheometer. The isothermal increase of viscosity during polyurethane

  18. Spatial growth of fundamental solutions for certain perturbations of the harmonic oscillator

    DEFF Research Database (Denmark)

    Jensen, Arne; Yajima, Kenji

    We consider the fundamental solution for the Cauchy problem for perturbations of the harmonic oscillator by time dependent potentials, which grow at spatial infinity slower than quadratic, but faster than linear functions, and whose Hessian matrices have a fixed sign. We prove that the fundamental...... solution at resonant times grows indefinitely at spatial infinity with the algebraic growth rate, which increases indefinitely, when the growth rate of perturbations at infinity decrease from the near quadratic to the near linear ones....

  19. Spatial growth of fundamental solutions for certain perturbations of the harmonic oscillator

    DEFF Research Database (Denmark)

    Jensen, Arne; Yajima, Kenji

    2010-01-01

    We consider the fundamental solution for the Cauchy problem for perturbations of the harmonic oscillator by time dependent potentials which grow at spatial infinity slower than quadratic but faster than linear functions and whose Hessian matrices have a fixed sign. We prove that the fundamental...... solution at resonant times grows indefinitely at spatial infinity with an algebraic growth rate, which increases indefinitely when the growth rate of perturbations at infinity decreases from the near quadratic to the near linear ones....

  20. The evaluation system of city's smart growth success rates

    Science.gov (United States)

    Huang, Yifan

    2018-04-01

    "Smart growth" is to pursue the best integrated perform+-ance of the Economically prosperous, socially Equitable, and Environmentally Sustainable(3E). Firstly, we establish the smart growth evaluation system(SGI) and the sustainable development evaluation system(SDI). Based on the ten principles and the definition of three E's of sustainability. B y using the Z-score method and the principal component analysis method, we evaluate and quantify indexes synthetically. Then we define the success of smart growth as the ratio of the SDI to the SGI composite score growth rate (SSG). After that we select two cities — Canberra and Durres as the objects of our model in view of the model. Based on the development plans and key data of these two cities, we can figure out the success of smart growth. And according to our model, we adjust some of the growth indicators for both cities. Then observe the results before and after adjustment, and finally verify the accuracy of the model.

  1. Growth-rate regulated genes have profound impact on interpretation of transcriptome profiling in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Regenberg, Birgitte; Grotkjær, Thomas; Winther, Ole

    2006-01-01

    Growth rate is central to the development of cells in all organisms. However, little is known about the impact of changing growth rates. We used continuous cultures to control growth rate and studied the transcriptional program of the model eukaryote Saccharomyces cerevisiae, with generation time...

  2. Growth Rates and Mechanisms of Magmatic Orbicule Formation: Insights from Calcium Isotopes

    Science.gov (United States)

    Antonelli, M. A.; Watkins, J. M.; DePaolo, D. J.

    2017-12-01

    Orbicular diorites and granites are rare plutonic rock textures that remain enigmatic despite a century of study. Orbicules consist of a rounded core (xenolith, xenocryst, or autolith) surrounded by a variable number of concentric rings defined by different modal mineralogies and textures. Recent work suggests that the alternating layers of mineral growth are a consequence of either changes in external conditions of the magma (e.g. temperature, magma composition due to mixing, changes in volatile abundances), or rapid growth of one mineral phase (e.g plagioclase) creating a depleted boundary layer that then promotes precipitation of an alternative mineral phase (e.g. pyroxene). This process can be repeated to produce multiple layers. The rates at which orbicules grow is also of interest and relates to the mechanisms. Studies of orbicular diorites from the northern Sierra Nevada suggest exceptionally high growth rates (McCarthy et al., 2016). Ca isotopes can offer a unique perspective on orbicule formation, as diffusive isotope fractionation should be substantial when growth rates are high, and they are also sensitive to the nature of the growth medium (silicate liquid or supercritical fluid phase). We present δ44Ca measurements and chemistry for a transect of a dioritic orbicule collected from Emerald Lake, California (Sierra Nevada), where the growth layers are defined by variations in plagioclase/pyroxene ratio, grain size, and texture. Ca concentration varies from 5-13 wt%, and d44Ca values oscillate between -0.5 to 0.0‰ relative to BSE, correlating with changes in mineralogy and texture. Zones of plagioclase comb texture are associated with negative δ44Ca excursions of -0.2 to -0.4‰, consistent with diffusive isotope fractionation during rapid mineral growth. Assuming a 10‰ difference in diffusivity for 44Ca vs. 40Ca in dioritic liquids (Watson et al., 2016), and using the models of Watson and Muller (2009) as a guide, these small fractionations

  3. Animal spirits, competitive markets, and endogenous growth

    Science.gov (United States)

    Miyazaki, Kenji

    2013-10-01

    This paper uses a simple model with an endogenous discount rate and linear technology to investigate whether a competitive equilibrium has a higher balanced growth path (BGP) than the social planning solution and whether the BGP is determinate or indeterminate. The implications are as follows. To start with, people with an instinct to compare themselves with others possess an endogenous discount rate. In turn, this instinct affects the economic growth rate in a competitive market economy. The competitive market economy also sometimes achieves higher economic growth than a social planning economy. However, the outcomes of market economy occasionally fluctuate because of the presence of the self-fulfilling prophecy or animal spirits.

  4. Hydrogen induced crack growth in Grade-12 titanium

    International Nuclear Information System (INIS)

    Ahn, T.M.; Lee, K.S.

    1984-01-01

    Internal hydrogen induced crack growth rates were measured in Grade-12 titanium which is a candidate material for high-level nuclear waste containers. As-received and hydrogen charged samples (5 ppM to 330 ppM hydrogen) were used for slow crack growth measurements at constant loads using a Krak Gauge. The testing temperature ranged from room temperature to 148 0 C. The crack growth kinetics under low to moderate loads are linear, but this linear rate is interrupted by discrete fast crack jump segments with parabolic or cubic type kinetics. These fast jump segments are thought to be associated with the passage of the crack front through the alpha-beta interface phase or with the initial loading sequence. By measuring striation spacings on the fracture surface, most crack growth rates observed are found to be in stage II. The striations are considered to be associated with hydride fracture. The crack path is either transgranular in the alpha phase or interfacial in the alpha phase adjacent to the beta phase. For transgranular growth, crack growth rates are constant and slower than those for interfacial growth which is associated with fast crack growth through a high hydrogen concentration region. Most stage II crack growth rates depend slightly on the stress intensity suggesting the contribution of plastic tearing process to stage II kinetics. The activation energies for crack growth are much lower than the activation energy of hydrogen diffusion through the alpha phase, implying that hydrogen is transported along dislocations, grain boundaries or interfaces. When the temperature is increased, the crack velocity first reaches a maximum and then decreases at higher temperatures. These temperature effects come from lower hydrogen concentration trapped at dislocations or from slower hydride nucleation kinetics, both at higher temperatures

  5. Growth rate distribution in the forming lateral root of arabidopsis.

    Science.gov (United States)

    Szymanowska-Pułka, Joanna; Lipowczan, Marcin

    2014-10-01

    Microscopic observations of lateral roots (LRs) in Arabidopsis thaliana reveal that the cross-sectional shape of the organ changes from its basal to its apical region. The founder cells for LRs are elongated along the parent root axis, and thus from the site of initiation the base of LRs resemble an ellipse. The circumference of the apical part of LRs is usually a circle. The objective of this study was to analyse the characteristics of changes in the growth field of LRs possessing various shapes in their basal regions. The LRs of the wild type (Col-0) and two transgenic arabidopsis lines were analysed. On the basis of measurements of the long and short diameters (DL and DS, respectively) of the ellipse-like figure representing the bases of particular LRs, their asymmetry ratios (DL/DS) were determined. Possible differences between accessions were analysed by applying statistical methods. No significant differences between accessions were detected. Comparisons were therefore made of the maximal, minimal and mean value of the ratio of all the LRs analysed. Taking into consideration the lack of circular symmetry of the basal part, rates of growth were determined at selected points on the surface of LRs by the application of the growth tensor method, a mathematical tool previously applied only to describe organs with rotational symmetry. Maps showing the distribution of growth rates were developed for surfaces of LRs of various asymmetry ratios. The maps of growth rates on the surfaces of LRs having various shapes of the basal part show differences in both the geometry and the manner of growth, thus indicating that the manner of growth of the LR primordium is correlated to its shape. This is the first report of a description of growth of an asymmetric plant organ using the growth tensor method. The mathematical modelling adopted in the study provides new insights into plant organ formation and shape. © The Author 2014. Published by Oxford University Press on

  6. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    Science.gov (United States)

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  7. Stress corrosion crack growth rate in dissimilar metal welds

    International Nuclear Information System (INIS)

    Fernandez, M. P.; Lapena, J.; Lancha, A. M.; Perosanz, F. J.; Navas, M.

    2000-01-01

    Dissimilar welds, used to join different sections in light water reactors, are potentially susceptible to stress corrosion cracking (SCC) in aqueous mediums characteristic of nuclear plants. However, the study of these The ma has been limited to evaluating the weld material susceptibility in these mediums. Little scarce data are available on crack growth rates due, fundamentally, to inadequate testing techniques. In order to address this lack of information the crack growth rate at the interface of ferritic SA 533 B-1 alloy and alloy I-82, in a dissimilar weld (SA533B-1/I-82/316L), was studied. Experiments were conducted in water at 288 degree centigrade, 8 ppm of O 2 and 1 μS/cm conductivity. (Author) 33 refs

  8. Hydrocarbon fermentation: kinetics of microbial cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Goma, G [Institut National des Sciences Appliquees, Toulouse; Ribot, D

    1978-11-01

    Modeling of microbial growth using nonmiscible substrate is studied when kinetics of substrate dissolution is rate limiting. When the substrate concentration is low, the growth rate is described by an analytical relation that can be identified as a Contois relationship. If the substrate concentration is greater than a critical value S/sub crit/, the potentially useful hydrocarbon S* concentration is described by S* = S/sub crit//(1 + S/sub crit//S). A relationship was found between S/sub crit/ and the biomass concentration X. When X increased, S/sub crit/ decreased. The cell growth rate is related to a relation ..mu.. = ..mu../sub m/(A(X/S/sub crit/)(1 + S/sub crit//S) + 1)/sup -1/. This model describes the evolution of the growth rate when exponential or linear growth occurs, which is related to physico-chemical properties and hydrodynamic fermentation conditions. Experimental data to support the model are presented.

  9. Growth rate effects on the formation of dislocation loops around deep helium bubbles in Tungsten

    International Nuclear Information System (INIS)

    Sandoval, Luis; Perez, Danny; Uberuaga, Blas P.; Voter, Arthur Ford

    2016-01-01

    Here, the growth process of spherical helium bubbles located 6 nm below a (100) surface is studied using molecular dynamics and parallel replica dynamics simulations, over growth rates from 10"6 to 10"1"2 helium atoms per second. Slower growth rates lead to a release of pressure and lower helium content as compared with fast growth cases. In addition, at slower growth rates, helium bubbles are not decorated by multiple dislocation loops, as these tend to merge or emit given sufficient time. At faster rates, dislocation loops nucleate faster than they can emit, leading to a more complicated dislocation structure around the bubble.

  10. Growth rates of important East African montane forest trees, with ...

    African Journals Online (AJOL)

    These trees showed growth rates at least twice as high as those of the primary species. Juniperus procera was found to be the fastest growing species in the cedar forest, underlining its success in forming dense stands after a fire. Only young Podocarpus latifolius showed a similar fast growth. Olea europaea ssp. cuspidata, ...

  11. Manipulating Rayleigh-Taylor Growth Using Adjoints

    Science.gov (United States)

    Kord, Ali; Capecelatro, Jesse

    2017-11-01

    It has been observed that initial interfacial perturbations affect the growth of Rayleigh-Taylor (RT) instabilities. However, it remains to be seen to what extent the perturbations alter the RT growth rate. Direct numerical simulations (DNS) provide a powerful means for studying the effects of initial conditions (IC) on the growth rate. However, a brute-force approach for identifying optimal initial perturbations is not practical via DNS. In addition, identifying sensitivity of the RT growth to the large number of parameters used in defining the IC is computationally expensive. A discrete adjoint is formulated to measure sensitivities of multi-mode RT growth to ICs in a high-order finite difference framework. The sensitivity is used as a search direction for adjusting the initial perturbations to both maximize and suppress the RT growth rate during its non-linear regime. The modes that contribute the greatest sensitivity are identified, and optimized perturbation energy spectrum are reported. PhD Student, Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI.

  12. Comparative Study of Worldwide Species of Genus Lentinus (=Lentinula, Higher Basidiomycetes) Based on Linear Mycelium Growth.

    Science.gov (United States)

    Mata, Juan Luis; Mishra, Nutan Tulapurkar

    2015-01-01

    Species of mushroom genus Lentinus (=Lentinula) are best known for the commercially important and extensively studied culinary-medicinal shiitake, L. edodes. A few mycelium growth studies have focused on Lentinus boryana, but information is lacking for L. raphanica and L. aciculospora, endemic to the Americas. In this study, 14 dikaryon strains representing 5 Lentinus species were grown on 5 nutritive agar media at increments of 5°C. Growth for each species was significantly slower on corn meal agar, but no differences were found among malt extract, potato dextrose, malt peptone, and yeast malt extract agars. Lentinus aciculospora and L. boryana consistently exhibited the slowest mycelium growth rates among all species and across all temperatures tested, with optima at 15°C and 20°C. The fastest mycelium growth rates for L. edodes, L. novaezelandiae, and L. raphanica occurred at 25°C. Strains of the latter continued to grow well at 30°C, whereas growth of the other 2 species declined significantly. Differences in mycelium growth rates for American strains could be partially explained by their geographic locations, indicating that understanding this physiological parameter has important ramifications for the edible mushroom industry.

  13. SCC crack growth rate of cold worked 316L stainless steel in PWR environment

    Science.gov (United States)

    Du, Donghai; Chen, Kai; Yu, Lun; lu, Hui; Zhang, Lefu; Shi, Xiuqiang; Xu, Xuelian

    2015-01-01

    Many component failures in nuclear power plants were found to be caused by stress corrosion cracking (SCC) of cold worked austenitic steels. Some of the pressure boundary component materials are even cold worked up to 35% plastic deformation, leaving high residual stress and inducing high growth rate of corrosion crack. Controlling water chemistry is one of the best counter measure to mitigate this problem. In this work, the effects of temperature (200 up to 325 °C) and dissolved oxygen (0 up to 2000 μg/L) on SCC crack growth rates of cold worked austenitic stainless steel type 316L have been tested by using direct current potential drop (DCPD) method. The results showed that temperature affected SCC crack growth rates more significantly in oxygenated water than in deaerated water. In argon deaerated water, the crack growth rate exhibited a peak at about 250 °C, which needs further verification. At 325 °C, the SCC crack growth rate increased rapidly with the increase of dissolved oxygen concentration within the range from 0 up to 200 μg/L, while when dissolved oxygen was above 200 μg/L, the crack growth rate followed a shallower dependence on dissolved oxygen concentration.

  14. Inflammation and linear bone growth: the inhibitory role of SOCS2 on GH/IGF-1 signaling.

    Science.gov (United States)

    Farquharson, Colin; Ahmed, S Faisal

    2013-04-01

    Linear bone growth is widely recognized to be adversely affected in children with chronic kidney disease (CKD) and other chronic inflammatory disorders. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) pathway is anabolic to the skeleton and inflammatory cytokines compromise bone growth through a number of different mechanisms, which include interference with the systemic as well as the tissue-level GH/IGF-1 axis. Despite attempts to promote growth and control disease, there are an increasing number of reports of the persistence of poor growth in a substantial proportion of patients receiving rhGH and/or drugs that block cytokine action. Thus, there is an urgent need to consider better and alternative forms of therapy that are directed specifically at the mechanism of the insult which leads to abnormal bone health. Suppressor of cytokine signaling 2 (SOCS2) expression is increased in inflammatory conditions including CKD, and is a recognized inhibitor of GH signaling. Therefore, in this review, we will focus on the premise that SOCS2 signaling represents a critical pathway in growth plate chondrocytes through which pro-inflammatory cytokines alter both GH/IGF-1 signaling and cellular function.

  15. Age, growth rate, and otolith growth of polar cod (Boreogadus saida in two fjords of Svalbard, Kongsfjorden and Rijpfjorden

    Directory of Open Access Journals (Sweden)

    Dariusz P. Fey

    2017-10-01

    Full Text Available This work presents biological information for polar cod (Boreogadus saida collected with a Campelen 1800 shrimp bottom trawl in Kongsfjorden (two stations located in the inner part of the fjord adjacent to the glacier and Rijpfjorden (one station at the entrance to the fjord in September and October 2013. The otolith-based ages of polar cod collected in Kongsfjorden (6.1–24 cm total length TL; n = 813 ranged from 0 to 4 years. The growth rate was relatively constant at approximately 4.7 cm year−1 between years 1 and 4, which indicates that growth was fast in the glacier area. The ages of polar cod collected in Rijpfjorden (8.6–15.9 cm TL; n = 64 ranged from 2 to 3 years. The fish from Rijpfjorden were smaller at age than those from Kongsfjorden, and their growth rate between years 2 and 3 (no other age classes were available was approximately 3.3 cm year−1. In both fjords, males and females were of the same size-at-age and the same weight-at-TL. The small sampling area means that the results on growth rate are not representative of the entire fjords. Instead, the results can be discussed as presenting the possible growth rates of some populations. A strong relationship was identified between otolith size (length and weight and fish size (TL and TW, with no differences between males and females or the fjords. A significant, strong relationship was also noted between fish and otolith growth rates.

  16. Linear Analysis of Converging Richtmyer-Meshkov Instability in the Presence of an Azimuthal Magnetic Field

    KAUST Repository

    Bakhsh, Abeer; Samtaney, Ravindra

    2017-01-01

    We investigate the linear stability of both positive and negative Atwood ratio interfaces accelerated either by a fast magnetosonic or hydrodynamic shock in cylindrical geometry. For the magnetohydrodynamic (MHD) case, we examine the role of an initial seed azimuthal magnetic field on the growth rate of the perturbation. In the absence of a magnetic field, the Richtmyer-Meshkov growth is followed by an exponentially increasing growth associated with the Rayleigh-Taylor instability. In the MHD case, the growth rate of the instability reduces in proportion to the strength of the applied magnetic field. The suppression mechanism is associated with the interference of two waves running parallel and anti-parallel to the interface that transport of vorticity and cause the growth rate to oscillate in time with nearly a zero mean value.

  17. Linear Analysis of Converging Richtmyer-Meshkov Instability in the Presence of an Azimuthal Magnetic Field

    KAUST Repository

    Bakhsh, Abeer

    2017-11-17

    We investigate the linear stability of both positive and negative Atwood ratio interfaces accelerated either by a fast magnetosonic or hydrodynamic shock in cylindrical geometry. For the magnetohydrodynamic (MHD) case, we examine the role of an initial seed azimuthal magnetic field on the growth rate of the perturbation. In the absence of a magnetic field, the Richtmyer-Meshkov growth is followed by an exponentially increasing growth associated with the Rayleigh-Taylor instability. In the MHD case, the growth rate of the instability reduces in proportion to the strength of the applied magnetic field. The suppression mechanism is associated with the interference of two waves running parallel and anti-parallel to the interface that transport of vorticity and cause the growth rate to oscillate in time with nearly a zero mean value.

  18. Effect of diffusion from a lateral surface on the rate of GaN nanowire growth

    International Nuclear Information System (INIS)

    Sibirev, N. V.; Tchernycheva, M.; Cirlin, G. E.; Patriarche, G.; Harmand, J. C.; Dubrovskii, V. G.

    2012-01-01

    The kinetics of the growth of GaN crystalline nanowires on a Si (111) surface with no catalyst is studied experimentally and theoretically. Noncatalytic GaN nanowires were grown by molecular-beam epitaxy with AlN inserts, which makes it possible to determine the rate of the vertical growth of nanowires. A model for the formation of GaN nanowires is developed, and an expression for their rate of growth is derived. It is shown that, in the general case, the dependence of the rate of growth on the nanowire diameter has a minimum. The diameter corresponding to the experimentally observed minimum of the rate of growth steadily increases with increasing diffusion flux from the lateral surface.

  19. Crack growth under combined creep and fatigue conditions in alloy 800

    International Nuclear Information System (INIS)

    Pfaffelhuber, M.; Roedig, M.; Schubert, F.; Nickel, H.

    1989-08-01

    To investigate the crack growth behaviour under combined creep-fatigue loading, CT 25 mm-specimens of X10NiCrAlTi 32 20 (Alloy 800) have been tested in experiments with cyclic loadings and hold times, with static loadings and short stress rekief interrupts, with ramp type loadings and with sequences of separate fatigue and creep crack growth periods. The test temperature of 700deg C was selected because only in this temperature range this alloy provides similar amounts of crack growth under creep and fatigue conditions due to equivalent stress levels. For the estimation of crack growth under combined loading conditions a linear accumulation of increase in crack length was proved using the crack growth laws of pure creep and fatigue crack growth. Hold time and ramp loadings lead to a higher crack growth rate compared with pure creep or pure fatigue crack growth tests. In hold time experiments the crack growth rate is higher than ramp tests of the same period time. The results of hold time tests can be fairly enough predicted by linear damage accumulation rules. (orig.) [de

  20. Mechanisms promoting higher growth rate in arctic than in temperate shorebirds

    NARCIS (Netherlands)

    Schekkerman, H.; Tulp, I.Y.M.; Piersma, T.; Visser, G.H.

    2003-01-01

    We compared prefledging growth, energy expenditure, and time budgets in the arctic-breeding red knot (Calidris canutus) to those in temperate shorebirds, to investigate how arctic chicks achieve a high growth rate despite energetic difficulties associated with precocial development in a cold

  1. Mechanisms promoting higher growth rate in arctic than in temperate shorebirds

    NARCIS (Netherlands)

    Schekkerman, H; Tulp, Ingrid; Piersma, T.; Visser, G.H.

    We compared prefledging growth, energy expenditure, and time budgets in the arctic-breeding red knot (Calidris canutus) to those in temperate shorebirds, to investigate how arctic chicks achieve a high growth rate despite energetic difficulties associated with precocial development in a cold

  2. Ecological regime shift drives declining growth rates of sea turtles throughout the West Atlantic

    Science.gov (United States)

    Bjorndal, Karen A.; Bolten, Alan B.; Chaloupka, Milani; Saba, Vincent S.; Bellini, Cláudio; Marcovaldi, Maria A.G.; Santos, Armando J.B.; Bortolon, Luis Felipe Wurdig; Meylan, Anne B.; Meylan, Peter A.; Gray, Jennifer; Hardy, Robert; Brost, Beth; Bresette, Michael; Gorham, Jonathan C.; Connett, Stephen; Crouchley, Barbara Van Sciver; Dawson, Mike; Hayes, Deborah; Diez, Carlos E.; van Dam, Robert P.; Willis, Sue; Nava, Mabel; Hart, Kristen M.; Cherkiss, Michael S.; Crowder, Andrew; Pollock, Clayton; Hillis-Starr, Zandy; Muñoz Tenería, Fernando A.; Herrera-Pavón, Roberto; Labrada-Martagón, Vanessa; Lorences, Armando; Negrete-Philippe, Ana; Lamont, Margaret M.; Foley, Allen M.; Bailey, Rhonda; Carthy, Raymond R.; Scarpino, Russell; McMichael, Erin; Provancha, Jane A.; Brooks, Annabelle; Jardim, Adriana; López-Mendilaharsu, Milagros; González-Paredes, Daniel; Estrades, Andrés; Fallabrino, Alejandro; Martínez-Souza, Gustavo; Vélez-Rubio, Gabriela M.; Boulon, Ralf H.; Collazo, Jaime; Wershoven, Robert; Hernández, Vicente Guzmán; Stringell, Thomas B.; Sanghera, Amdeep; Richardson, Peter B.; Broderick, Annette C.; Phillips, Quinton; Calosso, Marta C.; Claydon, John A.B.; Metz, Tasha L.; Gordon, Amanda L.; Landry, Andre M.; Shaver, Donna J.; Blumenthal, Janice; Collyer, Lucy; Godley, Brendan J.; McGowan, Andrew; Witt, Matthew J.; Campbell, Cathi L.; Lagueux, Cynthia J.; Bethel, Thomas L.; Kenyon, Lory

    2017-01-01

    Somatic growth is an integrated, individual-based response to environmental conditions, especially in ectotherms. Growth dynamics of large, mobile animals are particularly useful as bio-indicators of environmental change at regional scales. We assembled growth rate data from throughout the West Atlantic for green turtles, Chelonia mydas, which are long-lived, highly migratory, primarily herbivorous mega-consumers that may migrate over hundreds to thousands of kilometers. Our dataset, the largest ever compiled for sea turtles, has 9690 growth increments from 30 sites from Bermuda to Uruguay from 1973 to 2015. Using generalized additive mixed models, we evaluated covariates that could affect growth rates; body size, diet, and year have significant effects on growth. Growth increases in early years until 1999, then declines by 26% to 2015. The temporal (year) effect is of particular interest because two carnivorous species of sea turtles – hawksbills, Eretmochelys imbricata, and loggerheads, Caretta caretta – exhibited similar significant declines in growth rates starting in 1997 in the West Atlantic, based on previous studies. These synchronous declines in productivity among three sea turtle species across a trophic spectrum provide strong evidence that an ecological regime shift (ERS) in the Atlantic is driving growth dynamics. The ERS resulted from a synergy of the 1997/1998 El Niño Southern Oscillation (ENSO) – the strongest on record – combined with an unprecedented warming rate over the last two to three decades. Further support is provided by the strong correlations between annualized mean growth rates of green turtles and both sea surface temperatures (SST) in the West Atlantic for years of declining growth rates (r = -0.94) and the Multivariate ENSO Index (MEI) for all years (r = 0.74). Granger-causality analysis also supports the latter finding. We discuss multiple stressors that could reinforce and prolong the effect of the ERS. This study

  3. Ecological regime shift drives declining growth rates of sea turtles throughout the West Atlantic.

    Science.gov (United States)

    Bjorndal, Karen A; Bolten, Alan B; Chaloupka, Milani; Saba, Vincent S; Bellini, Cláudio; Marcovaldi, Maria A G; Santos, Armando J B; Bortolon, Luis Felipe Wurdig; Meylan, Anne B; Meylan, Peter A; Gray, Jennifer; Hardy, Robert; Brost, Beth; Bresette, Michael; Gorham, Jonathan C; Connett, Stephen; Crouchley, Barbara Van Sciver; Dawson, Mike; Hayes, Deborah; Diez, Carlos E; van Dam, Robert P; Willis, Sue; Nava, Mabel; Hart, Kristen M; Cherkiss, Michael S; Crowder, Andrew G; Pollock, Clayton; Hillis-Starr, Zandy; Muñoz Tenería, Fernando A; Herrera-Pavón, Roberto; Labrada-Martagón, Vanessa; Lorences, Armando; Negrete-Philippe, Ana; Lamont, Margaret M; Foley, Allen M; Bailey, Rhonda; Carthy, Raymond R; Scarpino, Russell; McMichael, Erin; Provancha, Jane A; Brooks, Annabelle; Jardim, Adriana; López-Mendilaharsu, Milagros; González-Paredes, Daniel; Estrades, Andrés; Fallabrino, Alejandro; Martínez-Souza, Gustavo; Vélez-Rubio, Gabriela M; Boulon, Ralf H; Collazo, Jaime A; Wershoven, Robert; Guzmán Hernández, Vicente; Stringell, Thomas B; Sanghera, Amdeep; Richardson, Peter B; Broderick, Annette C; Phillips, Quinton; Calosso, Marta; Claydon, John A B; Metz, Tasha L; Gordon, Amanda L; Landry, Andre M; Shaver, Donna J; Blumenthal, Janice; Collyer, Lucy; Godley, Brendan J; McGowan, Andrew; Witt, Matthew J; Campbell, Cathi L; Lagueux, Cynthia J; Bethel, Thomas L; Kenyon, Lory

    2017-11-01

    Somatic growth is an integrated, individual-based response to environmental conditions, especially in ectotherms. Growth dynamics of large, mobile animals are particularly useful as bio-indicators of environmental change at regional scales. We assembled growth rate data from throughout the West Atlantic for green turtles, Chelonia mydas, which are long-lived, highly migratory, primarily herbivorous mega-consumers that may migrate over hundreds to thousands of kilometers. Our dataset, the largest ever compiled for sea turtles, has 9690 growth increments from 30 sites from Bermuda to Uruguay from 1973 to 2015. Using generalized additive mixed models, we evaluated covariates that could affect growth rates; body size, diet, and year have significant effects on growth. Growth increases in early years until 1999, then declines by 26% to 2015. The temporal (year) effect is of particular interest because two carnivorous species of sea turtles-hawksbills, Eretmochelys imbricata, and loggerheads, Caretta caretta-exhibited similar significant declines in growth rates starting in 1997 in the West Atlantic, based on previous studies. These synchronous declines in productivity among three sea turtle species across a trophic spectrum provide strong evidence that an ecological regime shift (ERS) in the Atlantic is driving growth dynamics. The ERS resulted from a synergy of the 1997/1998 El Niño Southern Oscillation (ENSO)-the strongest on record-combined with an unprecedented warming rate over the last two to three decades. Further support is provided by the strong correlations between annualized mean growth rates of green turtles and both sea surface temperatures (SST) in the West Atlantic for years of declining growth rates (r = -.94) and the Multivariate ENSO Index (MEI) for all years (r = .74). Granger-causality analysis also supports the latter finding. We discuss multiple stressors that could reinforce and prolong the effect of the ERS. This study demonstrates the

  4. Extending the durability of cultivar resistance by limiting epidemic growth rates.

    Science.gov (United States)

    Carolan, Kevin; Helps, Joe; van den Berg, Femke; Bain, Ruairidh; Paveley, Neil; van den Bosch, Frank

    2017-09-27

    Cultivar resistance is an essential part of disease control programmes in many agricultural systems. The use of resistant cultivars applies a selection pressure on pathogen populations for the evolution of virulence, resulting in loss of disease control. Various techniques for the deployment of host resistance genes have been proposed to reduce the selection for virulence, but these are often difficult to apply in practice. We present a general technique to maintain the effectiveness of cultivar resistance. Derived from classical population genetics theory; any factor that reduces the population growth rates of both the virulent and avirulent strains will reduce selection. We model the specific example of fungicide application to reduce the growth rates of virulent and avirulent strains of a pathogen, demonstrating that appropriate use of fungicides reduces selection for virulence, prolonging cultivar resistance. This specific example of chemical control illustrates a general principle for the development of techniques to manage the evolution of virulence by slowing epidemic growth rates. © 2017 The Author(s).

  5. Causality Relationship Between Import, Export and Growth Rate in Developing Countries

    Directory of Open Access Journals (Sweden)

    Serhat YUKSEL

    2017-06-01

    Full Text Available In this paper, we tried to determine the relationship between imports, exports and growth rate in developing countries. Within this scope, 6 developing countries (Argentina, Brazil, China, Malaysia, Mexico and Turkey were analyzed in this study. In order to achieve this purpose, annual data for the periods between 1961 and 2014 was tested by using Engle Granger co-integration analysis, Vector Error Correction Model and Toda Yamamoto causality analysis. According to the result of the analysis, it was determined that there is not any relationship among three variables in Brazil and Mexico. On the other hand, we defined that increase in export causes higher growth rate in Argentina. Moreover, it was concluded that there is a causal relationship from import to export in China and Turkey. Furthermore, it was determined that export causes higher import in Malaysia. Therefore, it can be concluded that the relationship between import, export and growth rate is not same for all developing countries..

  6. Population growth, interest rate, and housing tax in the transitional China

    Science.gov (United States)

    He, Ling-Yun; Wen, Xing-Chun

    2017-03-01

    This paper combines and develops the models in Lastrapes (2002) and Mankiw and Weil (1989), which enables us to analyze the effects of interest rate and population growth shocks on housing price in one integrated framework. Based on this model, we carry out policy simulations to examine whether the housing (stock or flow) tax reduces the housing price fluctuations caused by interest rate or population growth shocks. Simulation results imply that the choice of housing tax tools depends on the kind of shock that housing market faces. In the situation where the housing price volatility is caused by the population growth shock, the flow tax can reduce the volatility of housing price while the stock tax makes no difference to it. If the shock is resulting from the interest rate, the policy maker should not impose any kind of the housing taxes. Furthermore, the effect of one kind of the housing tax can be strengthened by that of the other type of housing tax.

  7. Flute instability growth on a magnetized plasma column

    International Nuclear Information System (INIS)

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r i , where R is the Gaussian characteristic radius and r i is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation

  8. Guaranteed and computable bounds of the limit load for variational problems with linear growth energy functionals

    Czech Academy of Sciences Publication Activity Database

    Haslinger, Jaroslav; Repin, S.; Sysala, Stanislav

    2016-01-01

    Roč. 61, č. 5 (2016), s. 527-564 ISSN 0862-7940 R&D Projects: GA MŠk LQ1602 Institutional support: RVO:68145535 Keywords : functionals with linear growth * limit load * truncation method * perfect plasticity Subject RIV: BA - General Mathematics Impact factor: 0.618, year: 2016 http://link.springer.com/article/10.1007/s10492-016-0146-6

  9. State space and input-output linear systems

    CERN Document Server

    Delchamps, David F

    1988-01-01

    It is difficult for me to forget the mild sense of betrayal I felt some ten years ago when I discovered, with considerable dismay, that my two favorite books on linear system theory - Desoer's Notes for a Second Course on Linear Systems and Brockett's Finite Dimensional Linear Systems - were both out of print. Since that time, of course, linear system theory has undergone a transformation of the sort which always attends the maturation of a theory whose range of applicability is expanding in a fashion governed by technological developments and by the rate at which such advances become a part of engineering practice. The growth of the field has inspired the publication of some excellent books; the encyclopedic treatises by Kailath and Chen, in particular, come immediately to mind. Nonetheless, I was inspired to write this book primarily by my practical needs as a teacher and researcher in the field. For the past five years, I have taught a one semester first year gradu­ ate level linear system theory course i...

  10. Regeneration and growth rates of allofragments in four common stream plants

    DEFF Research Database (Denmark)

    Riis, Tenna; Madsen, Tom Vindbæk; Sennels, R. S. H.

    2009-01-01

    perfoliatus L. and Ranunculus baudotii x pseudofluitans. The objectives of this study were to determine (1) if shoots with an apical tip have higher regeneration (growth of new shoots and rhizomes from allofragments) and colonisation (root attachment in sediment) abilities and higher relative growth rates...

  11. Growth rates of rhizosphere microorganisms depend on competitive abilities of plants for nitrogen

    Science.gov (United States)

    Blagodatskaya, Evgenia; Littschwager, Johanna; Lauerer, Marianna; Kuzyakov, Yakov

    2010-05-01

    Rhizosphere - one of the most important ‘hot spots' in soil - is characterized not only by accelerated turnover of microbial biomass and nutrients but also by strong intra- and inter-specific competition. Intra-specific competition occurs between individual plants of the same species, while inter-specific competition can occur both at population level (plant species-specific, microbial species-specific interactions) and at community level (plant - microbial interactions). Such plant - microbial interactions are mainly governed by competition for available N sources, since N is one of the main growth limiting nutrients in natural ecosystems. Functional structure and activity of microbial community in rhizosphere is not uniform and is dependent on quantity and quality of root exudates which are plant specific. It is still unclear how microbial growth and turnover in the rhizosphere are dependent on the features and competitive abilities of plants for N. Depending on C and N availability, acceleration and even retardation of microbial activity and carbon mineralization can be expected in the rhizosphere of plants with high competitive abilities for N. We hypothesized slower microbial growth rates in the rhizosphere of plants with smaller roots, as they usually produce less exudates compared to plants with small shoot-to-root ratio. As the first hypothesis is based solely on C availability, we also expected the greater effect of N availability on microbial growth in rhizosphere of plants with smaller root mass. These hypothesis were tested for two plant species of strawberry: Fragaria vesca L. (native species), and Duchesnea indica (Andrews) Focke (an invasive plant in central Europe) growing in intraspecific and interspecific competition. Microbial biomass and the kinetic parameters of microbial growth in the rhizosphere were estimated by dynamics of CO2 emission from the soil amended with glucose and nutrients. Specific growth rate (µ) of soil microorganisms was

  12. Influence of temperature on growth rate and lag phase of fungi isolated from Argentine corn.

    Science.gov (United States)

    González, H H; Resnik, S L; Vaamonde, G

    1988-03-01

    The influence of temperature on the growth of nine strains of fungi belonging to the genera Eurotium, Aspergillus, Penicillium and Fusarium has been investigated for the temperature range 15-35 degrees C. The lag phase and the growth rate were evaluated by using a laboratory medium. The maximum growth rate for E. repens, A. wentii and P. chrysogenum was observed at about 25 degrees C, for P. citrinum near 30 degrees C and for F. semitectum and F. moniliforme between 20 and 25 degrees C. The growth rate of A. niger, A. flavus and A. parasiticus increased with increasing temperatures in the range studied. For all strains studied it appeared that the higher the growth rate the lower the lag phase was.

  13. Plasma endotoxin core antibody concentration and linear growth are unrelated in rural Malawian children aged 2-5 years

    Science.gov (United States)

    Environmental enteropathy is subclinical inflammation of the upper gastrointestinal tract associated with reduced linear growth in developing countries. Usually investigators have used biopsy or a dual sugar absorption test to assess environmental enteropathy. Such tests are time and resource intens...

  14. Experimental study of linear and nonlinear regimes of density-driven instabilities induced by CO2 dissolution in water

    International Nuclear Information System (INIS)

    Outeda, R.; D'Onofrio, A.; El Hasi, C.; Zalts, A.

    2014-01-01

    Density driven instabilities produced by CO 2 (gas) dissolution in water containing a color indicator were studied in a Hele Shaw cell. The images were analyzed and instability patterns were characterized by mixing zone temporal evolution, dispersion curves, and the growth rate for different CO 2 pressures and different color indicator concentrations. The results obtained from an exhaustive analysis of experimental data show that this system has a different behaviour in the linear regime of the instabilities (when the growth rate has a linear dependence with time), from the nonlinear regime at longer times. At short times using a color indicator to see the evolution of the pattern, the images show that the effects of both the color indicator and CO 2 pressure are of the same order of magnitude: The growth rates are similar and the wave numbers are in the same range (0–30 cm −1 ) when the system is unstable. Although in the linear regime the dynamics is affected similarly by the presence of the indicator and CO 2 pressure, in the nonlinear regime, the influence of the latter is clearly more pronounced than the effects of the color indicator

  15. Growth and characterization of nanodiamond layers prepared using the plasma-enhanced linear antennas microwave CVD system

    Energy Technology Data Exchange (ETDEWEB)

    Fendrych, Frantisek; Taylor, Andrew; Peksa, Ladislav; Kratochvilova, Irena; Kluiber, Zdenek; Fekete, Ladislav [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, CZ-18221 Prague 8 (Czech Republic); Vlcek, Jan [Department of Physics and Measurement, Institute of Chemical Technology Prague, Technicka 5, CZ-16628 Prague 6 (Czech Republic); Rezacova, Vladimira; Petrak, Vaclav [Faculty of Biomedical Engineering, Czech Technical University, Sitna 3105, CZ-27201 Kladno 2 (Czech Republic); Liehr, Michael [Leybold Optics Dresden GmbH, Zur Wetterwarte 50, D-01109 Dresden (Germany); Nesladek, Milos, E-mail: fendrych@fzu.c [IMOMEC division, IMEC, Institute for Materials Research, University Hasselt, Wetenschapspark 1, B-3590 Diepenbeek (Belgium)

    2010-09-22

    Industrial applications of plasma-enhanced chemical vapour deposition (CVD) diamond grown on large area substrates, 3D shapes, at low substrate temperatures and on standard engineering substrate materials require novel plasma concepts. Based on the pioneering work of the group at AIST in Japan, the high-density coaxial delivery type of plasmas has been explored (Tsugawa et al 2006 New Diamond Front. Carbon Technol. 16 337-46). However, an important challenge is to obtain commercially interesting growth rates at very low substrate temperatures. In this work we introduce the concept of novel linear antenna sources, designed at Leybold Optics Dresden, using high-frequency pulsed MW discharge with a high plasma density. This type of pulse discharges leads to the preparation of nanocrystalline diamond (NCD) thin films, compared with ultra-NCD thin films prepared in (Tsugawa et al 2006 New Diamond Front. Carbon Technol. 16 337-46). We present optical emission spectroscopy data for the CH{sub 4}-CO{sub 2}-H{sub 2} gas chemistry and we discuss the basic properties of the NCD films grown.

  16. The effect of salinity on growth rate and osmolyte concentration of ...

    African Journals Online (AJOL)

    Although at a slower rate, growth is maintained in seawater cultures supplemented with nutrients. Differences were found in carbohydrate content between cultures in different growth media. The highest carbohydrate content was observed in cultures growing in Zarrouk medium supplemented with 4 NaCl and in seawater ...

  17. Comparison of cyanobacterial and green algal growth rates at different temperatures

    NARCIS (Netherlands)

    Lurling, M.; Faassen, E.J.; Kosten, S.; Eshetu, Z.; Huszar, V.M.

    2013-01-01

    1.The hypothesis that cyanobacteria have higher optimum growth temperatures and higher growth rates at the optimum as compared to chlorophytes was tested by running a controlled experiment with eight cyanobacteria species and eight chlorophyte species at six different temperatures (20-35°C) and by

  18. Measurement of fatigue crack growth rate of reactor structural material in air based on DCPD method

    International Nuclear Information System (INIS)

    Du Donghai; Chen Kai; Yu Lun; Zhang Lefu; Shi Xiuqiang; Xu Xuelian

    2014-01-01

    The principles and details of direct current potential drop (DCPD) in monitoring the crack growth of reactor structural materials was introduced in this paper. Based on this method, the fatigue crack growth rate (CGR) of typical structural materials in nuclear power systems was measured. The effects of applied load, load ratio and loading frequency on the fatigue crack growth rate of reactor structural materials were discussed. The result shows that the fatigue crack growth rate of reactor structural materials depends on the hardness of materials, and the harder the material is, the higher the rate of crack growth is. (authors)

  19. Volume doubling time and growth rate of renal cell carcinoma determined by helical CT: a single-institution experience

    International Nuclear Information System (INIS)

    Lee, Ji Young; Kim, Chan Kyo; Choi, Dongil; Park, Byung Kwan

    2008-01-01

    The purpose of this study was to retrospectively evaluate the volume doubling time (VDT) and growth rate of renal cell carcinomas (RCC) on a serial computed tomography (CT) scan. Thirty pathologically proven RCCs were reviewed with helical CT. Each tumor underwent at least two CT scans. Tumor volume was determined using an area measuring tool and the summation-of-areas technique. Growth rate was evaluated in terms of diameter and volume changes. VDT and volume growth rate were compared in relation to several factors (initial diameter, initial volume, diameter growth rate, volume growth rate, tumor grade, tumor subtype, sex or age). Mean VDT of RCCs was 505 days. Mean diameter and volume growth rate were 0.59 cm/year and 19.1 cm 3 /year, respectively. For volume and diameter growth rate, tumors ≤4 cm showed lower rates than those >4 cm (P 0.05). Volume growth rate was moderately to strongly positively correlated with initial diameter, initial volume and diameter growth rate (P < 0.05). In conclusion, small RCCs grew at a slow rate both diametrically and volumetrically. More accurate assessment of tumor growth rate and VDT may be helpful to understand the natural history of RCC. (orig.)

  20. Exchange-Driven Growth with Birth Rate Less Than Death

    International Nuclear Information System (INIS)

    Lin Zhenquan; Ye Gaoxiang; Ke Jianhong

    2005-01-01

    We further study the kinetic behavior of the exchange-driven growth with birth and death for the case of birth rate kernel being less than that of death based on the mean-field theory. The symmetric exchange rate kernel is K(k,j) = K'(k,j) = Ikj υ , and the birth and death rates are proportional to the aggregate's size. The long time asymptotic behavior of the aggregate size distribution a k (t) is found to obey a much unusual scaling law with an exponentially growing scaling function Φ(x) = exp (x).

  1. The Effect of Growth Temperature and V/III Flux Ratio of MOCVD Antimony Based Semiconductors on Growth Rate and Surface Morphology

    Directory of Open Access Journals (Sweden)

    Ramelan Ari Handono

    2017-01-01

    Full Text Available Epitaxial Alx Ga1-x Sb layers on GaSb and GaAs substrates have been grown by atmospheric pressure metalorganic chemical vapor deposition using TMAl, TMGa and TMSb. Nomarski microscope and a profiler were employed to examine the surface morphology and growth rate of the samples. We report the effect of growth temperature and V/III flux ratio on growth rate and surface morphology. Growth temperatures in the range of 520°C and 680°C and V/III ratios from 1 to 5 have been investigated. A growth rate activation energy of 0.73 eV was found. At low growth temperatures between 520 and 540°C, the surface morphology is poor due to antimonide precipitates associated with incomplete decomposition of the TMSb. For layers grown on GaAs at 580°C and 600°C with a V/III ratio of 3 a high quality surface morphology is typical, with a mirror-like surface and good composition control. It was found that a suitable growth temperature and V/III flux ratio was beneficial for producing good AlGaSb layers. Undoped AlGaSb grown at 580°C with a V/III flux ratio of 3 at the rate of 3.5 μm/hour shows p-type conductivity with smooth surface morphology

  2. Influence of water relations and growth rate on plant element uptake and distribution

    International Nuclear Information System (INIS)

    Greger, Maria

    2006-02-01

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution

  3. Influence of water relations and growth rate on plant element uptake and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2006-02-15

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution.

  4. The use of Ampelisca abdita growth rate as an indicator of sediment quality

    International Nuclear Information System (INIS)

    Weston, D.P.; Thompson, B.

    1995-01-01

    Acute lethal bioassays with amphipod crustaceans are routinely used to assess toxicity of bulk sediments. A study within the San Francisco Bay Regional Monitoring Program (RMP) is in progress to develop a chronic bioassay with the amphipod Ampelisca abdita, measuring both survivorship and growth rates. This approach is attractive because depression of growth rate is likely to be a more sensitive indicator of toxic effects than acute lethality, and natural populations of A. abdita exist throughout the Bay. Spiked sediment bioassays, using cadmium and crude oil, were used to demonstrate the relative sensitivity of the standard 10-day lethal test vs. the 30-day growth test. Sediments were also collected from 9 sites throughout the Bay, ranging from areas adjacent to municipal wastewater discharges to areas distant from known point source inputs. These samples were then split, and used for side-by-side comparison of acute (lethal) and chronic (growth) toxicity tests. Survivorship exceeded 90% in all tests, including those sediments collected nearest the wastewater outfalls. Growth rates were contrasted among the various treatments to examine the utility of this end point in discriminating the outfall sites. Data on the spatial distribution, abundance, and size-frequency distribution of native populations was examined within the context of using growth rate as an indicator of toxic effects in natural populations as well

  5. Using hierarchical linear growth models to evaluate protective mechanisms that mediate science achievement

    Science.gov (United States)

    von Secker, Clare Elaine

    The study of students at risk is a major topic of science education policy and discussion. Much research has focused on describing conditions and problems associated with the statistical risk of low science achievement among individuals who are members of groups characterized by problems such as poverty and social disadvantage. But outcomes attributed to these factors do not explain the nature and extent of mechanisms that account for differences in performance among individuals at risk. There is ample theoretical and empirical evidence that demographic differences should be conceptualized as social contexts, or collections of variables, that alter the psychological significance and social demands of life events, and affect subsequent relationships between risk and resilience. The hierarchical linear growth models used in this dissertation provide greater specification of the role of social context and the protective effects of attitude, expectations, parenting practices, peer influences, and learning opportunities on science achievement. While the individual influences of these protective factors on science achievement were small, their cumulative effect was substantial. Meta-analysis conducted on the effects associated with psychological and environmental processes that mediate risk mechanisms in sixteen social contexts revealed twenty-two significant differences between groups of students. Positive attitudes, high expectations, and more intense science course-taking had positive effects on achievement of all students, although these factors were not equally protective in all social contexts. In general, effects associated with authoritative parenting and peer influences were negative, regardless of social context. An evaluation comparing the performance and stability of hierarchical linear growth models with traditional repeated measures models is included as well.

  6. Transcription factor control of growth rate dependent genes in Saccharomyces cerevisiae: A three factor design

    DEFF Research Database (Denmark)

    Fazio, Alessandro; Jewett, Michael Christopher; Daran-Lapujade, Pascale

    2008-01-01

    , such as Ace2 and Swi6, and stress response regulators, such as Yap1, were also shown to have significantly enriched target sets. Conclusion: Our work, which is the first genome-wide gene expression study to investigate specific growth rate and consider the impact of oxygen availability, provides a more......Background: Characterization of cellular growth is central to understanding living systems. Here, we applied a three-factor design to study the relationship between specific growth rate and genome-wide gene expression in 36 steady-state chemostat cultures of Saccharomyces cerevisiae. The three...... factors we considered were specific growth rate, nutrient limitation, and oxygen availability. Results: We identified 268 growth rate dependent genes, independent of nutrient limitation and oxygen availability. The transcriptional response was used to identify key areas in metabolism around which m...

  7. Airborne measurements of nucleation mode particles I: coastal nucleation and growth rates

    Directory of Open Access Journals (Sweden)

    C. D. O'Dowd

    2007-01-01

    Full Text Available A light aircraft was equipped with a bank of Condensation Particle Counters (CPCs (50% cut from 3–5.4–9.6 nm and a nano-Scanning Mobility Particle Sizer (nSMPS and deployed along the west coast of Ireland, in the vicinity of Mace Head. The objective of the exercise was to provide high resolution micro-physical measurements of the coastal nucleation mode in order to map the spatial extent of new particle production regions and to evaluate the evolution, and associated growth rates of the coastal nucleation-mode aerosol plume. Results indicate that coastal new particle production is occurring over most areas along the land-sea interface with peak concentrations at the coastal plume-head in excess of 106 cm−3. Pseudo-Lagrangian studies of the coastal plume evolution illustrated significant growth of new particles to sizes in excess of 8 nm approximately 10 km downwind of the source region. Close to the plume head (<1 km growth rates can be as high as 123–171 nm h−1, decreasing gradually to 53–72 nm h−1 at 3 km. Further along the plume, at distances up to 10 km, the growth rates are calculated to be 17–32 nm h−1. Growth rates of this magnitude suggest that after a couple of hours, coastal nucleation mode particles can reach significant sizes where they can contribution to the regional aerosol loading.

  8. Species Diversity Enhances Predator Growth Rates

    International Nuclear Information System (INIS)

    Olson, M.H.; Jacobs, R.P.; O'Donnell, E.B.

    2007-01-01

    Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index) and growth rates of largemouth bass (Micropterus salmoides). This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

  9. A Longitudinal Study and Color Rating System of Acquisition Cost Growth

    Science.gov (United States)

    2017-03-23

    cost growth analysis. Ways in which this research can be carried forward include: • Collect more SAR data to further populate our research database... Growth Cory N. D’Amico Follow this and additional works at: https://scholar.afit.edu/etd Part of the Finance and Financial Management Commons This...and Color Rating System of Acquisition Cost Growth " (2017). Theses and Dissertations. 781. https://scholar.afit.edu/etd/781 A Longitudinal

  10. Effect of extremely low frequency electromagnetic fields on growth rate and morphology of bacteria.

    Science.gov (United States)

    Inhan-Garip, Ayse; Aksu, Burak; Akan, Zafer; Akakin, Dilek; Ozaydin, A Nilufer; San, Tangul

    2011-12-01

    To determine the effect of extremely low frequency (bacteria and to determine any morphological changes that might have been caused by ELF-EMF. Six bacterial strains, three Gram-negative and three Gram-positive were subjected to 50 Hz, 0.5 mT ELF-EMF for 6 h. To determine growth rate after ELF-EMF application, bacteria exposed to ELF-EMF for 3 h were collected, transferred to fresh medium and cultured without field application for another 4 h. Growth-rate was determined by optical density (OD) measurements made every hour. Morphological changes were determined with Transmission electron microscopy (TEM) for two gram-negative and two gram-positive strains collected after 3 h of field application. A decrease in growth rate with respect to control samples was observed for all strains during ELF-EMF application. The decrease in growth-rate continued when exposed bacteria were cultured without field application. Significant ultrastructural changes were observed in all bacterial strains, which were seen to resemble the alterations caused by cationic peptides. This study shows that ELF-EMF induces a decrease in growth rate and morphological changes for both Gram-negative and Gram-positive bacteria.

  11. Inferring time derivatives including cell growth rates using Gaussian processes

    Science.gov (United States)

    Swain, Peter S.; Stevenson, Keiran; Leary, Allen; Montano-Gutierrez, Luis F.; Clark, Ivan B. N.; Vogel, Jackie; Pilizota, Teuta

    2016-12-01

    Often the time derivative of a measured variable is of as much interest as the variable itself. For a growing population of biological cells, for example, the population's growth rate is typically more important than its size. Here we introduce a non-parametric method to infer first and second time derivatives as a function of time from time-series data. Our approach is based on Gaussian processes and applies to a wide range of data. In tests, the method is at least as accurate as others, but has several advantages: it estimates errors both in the inference and in any summary statistics, such as lag times, and allows interpolation with the corresponding error estimation. As illustrations, we infer growth rates of microbial cells, the rate of assembly of an amyloid fibril and both the speed and acceleration of two separating spindle pole bodies. Our algorithm should thus be broadly applicable.

  12. Growth performance of commercial temperate mushrooms Agaricus bisporus and Hypsizygus sp. under local environment

    International Nuclear Information System (INIS)

    Rosnani Abdul Rashid; Mat Rasol Awang; Hassan Hamdani Hassan Mutaat; Mohd Meswan Maskom

    2010-01-01

    To date, the Malaysian mushroom industry focuses on only seven species of mushroom for commercial purpose. To expand and further develop the mushroom industry, new mushroom species should be introduced into our local market. Temperate mushrooms are possible to be cultivated commercially in Malaysia but the optimisation of growth performance for high quality spawn and high mushroom yield need to be studied. In the present study the growth performance of mycelia of Agaricus bisporus and Hypsizygus sp. on culture media and substrates were investigated. Four types of culture media, viz. Potato Dextrose Agar (PDA), Nutrient Agar (NA), Malt Yeast Extract (MYE) and Complete Yeast Media (CYM) were used to determine the suitable culturing media for mycelial growth. The mycelia were inoculated on oil palm empty fruit bunch (EFB) and sawdust substrate and incubated at room temperature and in a low temperature in incubation room (10 - 12 degree Celsius). From the observation, Agaricus bisporus grew better on Malt Yeast Extract (MYE) medium with a growth rate of 0.306 cm/ day. Complete Yeast Media (CYM) was found more suitable for Hypsizygus sp. with a growth rate of 1.049 cm/ day. The linear growth rate of mycelium as measured on the surface of mushroom bag of Agaricus bisporus on EFB incubated at room temperature was 0.4364 cm/ day and cool temperature was 0.055 cm/ day. For Hypsizygus sp. the linear growth rate of the mycelium was 2.11 cm/ day. The linear growth of Hypsizygus sp. on sawdust substrate incubated in cool temperature was 1.4 cm/ day. (author)

  13. Impact of Macroeconomic Policies on Poverty and Unemployment Rates in Nigeria, Implications for Attaining Inclusive Growth

    Directory of Open Access Journals (Sweden)

    Philip Nwosa

    2016-04-01

    Full Text Available This paper examined the effect of macroeconomic policies on unemployment and poverty rates in Nigeria from 1980 to 2013 with implication to achieving inclusive growth. The inability of macroeconomic policies in addressing the rising issues unemployment and poverty rates in Nigeria despite the impressive economic growth experience over the last decades has increasingly called for the need for the pursuance of inclusive growth to address the social issues of unemployment and poverty rate. Previous studies have not considered the extent to which macroeconomic policies affects unemployment and poverty rate in Nigeria, and the implication of this relationship to the attainment of inclusive growth in Nigeria. The study adopts the Ordinary Least Square (OLS technique. The study observed that among macroeconomic policy variables only exchange rate significantly influenced unemployment rate while only fiscal policy significantly influenced and poverty rate. This implies that present macroeconomic policies in Nigeria do not guarantee the attainment of inclusive growth in Nigeria. The contribution of the paper is that to achieve inclusive growth that guarantees high employment and reduced poverty rate, there is the need for a re-examination of macroeconomic policy management in Nigeria.

  14. Longitudinal mathematics development of students with learning disabilities and students without disabilities: a comparison of linear, quadratic, and piecewise linear mixed effects models.

    Science.gov (United States)

    Kohli, Nidhi; Sullivan, Amanda L; Sadeh, Shanna; Zopluoglu, Cengiz

    2015-04-01

    Effective instructional planning and intervening rely heavily on accurate understanding of students' growth, but relatively few researchers have examined mathematics achievement trajectories, particularly for students with special needs. We applied linear, quadratic, and piecewise linear mixed-effects models to identify the best-fitting model for mathematics development over elementary and middle school and to ascertain differences in growth trajectories of children with learning disabilities relative to their typically developing peers. The analytic sample of 2150 students was drawn from the Early Childhood Longitudinal Study - Kindergarten Cohort, a nationally representative sample of United States children who entered kindergarten in 1998. We first modeled students' mathematics growth via multiple mixed-effects models to determine the best fitting model of 9-year growth and then compared the trajectories of students with and without learning disabilities. Results indicate that the piecewise linear mixed-effects model captured best the functional form of students' mathematics trajectories. In addition, there were substantial achievement gaps between students with learning disabilities and students with no disabilities, and their trajectories differed such that students without disabilities progressed at a higher rate than their peers who had learning disabilities. The results underscore the need for further research to understand how to appropriately model students' mathematics trajectories and the need for attention to mathematics achievement gaps in policy. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  15. Exchange Rate Volatility and Employment Growth in Developing Countries: Evidence from Turkey

    OpenAIRE

    Demir, Firat

    2010-01-01

    Employing a unique panel of 691 private firms that accounted for 26% of total value-added in manufacturing in Turkey, the paper explores the impacts of exchange rate volatility on employment growth during the period of 1983 - 2005. The empirical analysis using a variety of specifications, estimation techniques, and robustness tests suggests that exchange rate volatility has a statistically and economically significant employment growth reducing effect on manufacturing firms. Using point estim...

  16. Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post-mitotic growth rates.

    Science.gov (United States)

    Kavanová, Monika; Lattanzi, Fernando Alfredo; Schnyder, Hans

    2008-06-01

    Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

  17. Colorimetry provides a rapid objective measurement of de novo hair growth rate in mice.

    Science.gov (United States)

    Tzung, Tien-Yi; Yang, Chia-Yi; Huang, Yung-Chang; Kao, Fu-Jen

    2009-11-01

    Depilated mice have been used as a test platform for hair growth-regulating agents. However, currently available assessment tools for hair growth in mice are less than ideal. Tristimulus colorimetry of the fur color of depilated agouti, albino, and black mice with L*, a*, and b* values were performed daily until the full growth of pelage. Using light-emitting diode (LED) irradiation (650 and 890 nm) with a daily dose of 3.5 J/cm(2) as hair growth regulators, the hair growth rates observed by the global assessment were compared with those derived from colorimetry. In contrast to a* and b* values, L* values changed more drastically over time in the anagen phase regardless of fur color. Unlike the inhibitory effect of 650 nm irradiation, LED of 890 nm promoted de novo hair regrowth in mice. The difference in hair growth rates detected by colorimetry paralleled the observation made by the global assessment. The L* value of fur color obtained by tristimulus colorimetry was a sensitive yet quantitative indicator of de novo hair growth, and could be used to project the hair growth rate in mice.

  18. An optimal policy for deteriorating items with time-proportional deterioration rate and constant and time-dependent linear demand rate

    Science.gov (United States)

    Singh, Trailokyanath; Mishra, Pandit Jagatananda; Pattanayak, Hadibandhu

    2017-12-01

    In this paper, an economic order quantity (EOQ) inventory model for a deteriorating item is developed with the following characteristics: (i) The demand rate is deterministic and two-staged, i.e., it is constant in first part of the cycle and linear function of time in the second part. (ii) Deterioration rate is time-proportional. (iii) Shortages are not allowed to occur. The optimal cycle time and the optimal order quantity have been derived by minimizing the total average cost. A simple solution procedure is provided to illustrate the proposed model. The article concludes with a numerical example and sensitivity analysis of various parameters as illustrations of the theoretical results.

  19. Effect of different saccharides on growth, sporulation rate and d ...

    African Journals Online (AJOL)

    MFCS

    2012-05-17

    May 17, 2012 ... general, high sporulation rate was related with high growth rate and high viable cell count (>1.5 x 1012 cfu/ml). .... The sterile culture medium (180 ml) in a 1000 ml Erlenmeyer flask was ... The column temperature was set at 85°C. A series of ..... inactivation of certain sugar-metabolizing operons, such as lac ...

  20. Population Growth Rate, Life Expectancy and Pension Program Improvement in China

    OpenAIRE

    Yang, Zaigui

    2008-01-01

    Applying an overlapping-generations model with lifetime uncertainty, we examine in this paper China’s partially funded public pension system. The findings show that the individual contribution rate does not affect the capital-labor ratio but the firm contribution rate does. The optimal firm contribution rate depends on the capital share of income, social discount factor, survival probability, and population growth rate. The simulation results indicate that the optimal firm contribution rate r...

  1. H2 Control for the Continuous-Time Markovian Jump Linear Uncertain Systems with Partly Known Transition Rates and Input Quantization

    Directory of Open Access Journals (Sweden)

    Xin-Gang Zhao

    2013-01-01

    Full Text Available For a class of continuous-time Markovian jump linear uncertain systems with partly known transition rates and input quantization, the H2 state-feedback control design is considered. The elements in the transition rates matrix include completely known, boundary known, and completely unknown ones. First, an H2 cost index for Markovian jump linear uncertain systems is introduced; then by introducing a new matrix inequality condition, sufficient conditions are formulated in terms of linear matrix inequalities (LMIs for the H2 control of the Markovian jump linear uncertain systems. Less conservativeness is achieved than the result obtained with the existing technique. Finally, a numerical example is given to verify the validity of the theoretical results.

  2. Translation elicits a growth rate-dependent, genome-wide, differential protein production in Bacillus subtilis.

    Science.gov (United States)

    Borkowski, Olivier; Goelzer, Anne; Schaffer, Marc; Calabre, Magali; Mäder, Ulrike; Aymerich, Stéphane; Jules, Matthieu; Fromion, Vincent

    2016-05-17

    Complex regulatory programs control cell adaptation to environmental changes by setting condition-specific proteomes. In balanced growth, bacterial protein abundances depend on the dilution rate, transcript abundances and transcript-specific translation efficiencies. We revisited the current theory claiming the invariance of bacterial translation efficiency. By integrating genome-wide transcriptome datasets and datasets from a library of synthetic gfp-reporter fusions, we demonstrated that translation efficiencies in Bacillus subtilis decreased up to fourfold from slow to fast growth. The translation initiation regions elicited a growth rate-dependent, differential production of proteins without regulators, hence revealing a unique, hard-coded, growth rate-dependent mode of regulation. We combined model-based data analyses of transcript and protein abundances genome-wide and revealed that this global regulation is extensively used in B. subtilis We eventually developed a knowledge-based, three-step translation initiation model, experimentally challenged the model predictions and proposed that a growth rate-dependent drop in free ribosome abundance accounted for the differential protein production. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  3. Linear radial pulsation theory. Lecture 5

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    We describe a method for getting an equilibrium stellar envelope model using as input the total mass, the envelope mass, the surface effective temperature, the total surface luminosity, and the composition of the envelope. Then wih the structure of the envelope model known, we present a method for obtaining the raidal pulsation periods and growth rates for low order modes. The large amplitude pulsations observed for the yellow and red giants and supergiants are always these radial models, but for the stars nearer the main sequence, as for all of our stars and for the white dwarfs, there frequently are nonradial modes occuring also. Application of linear theory radial pulsation theory is made to the giant star sigma Scuti variables, while the linear nonradial theory will be used for the B stars in later lectures

  4. Asset growth strategy and bank performance in Nigeria | Toby ...

    African Journals Online (AJOL)

    This study examines the nature of the relationship between asset growth rate and growth in such output variables as total cost, total income and net profit In the Nigerian banking industry. Based on the data of 25 quoted Nigerian banks, three linear regression models were estimated complemented by descriptive data ...

  5. Poor glycemic control impacts linear and non-linear dynamics of heart rate in DM type 2

    Directory of Open Access Journals (Sweden)

    Daniela Bassi

    2015-08-01

    Full Text Available INTRODUCTION: It is well known that type 2 diabetes mellitus (T2DM produces cardiovascular autonomic neuropathy (CAN, which may affect the cardiac autonomic modulation. However, it is unclear whether the lack of glycemic control in T2DM without CAN could impact negatively on cardiac autonomic modulation. Objective: To evaluate the relationship between glycemic control and cardiac autonomic modulation in individuals with T2DM without CAN. Descriptive, prospective and cross sectional study.METHODS: Forty-nine patients with T2DM (51±7 years were divided into two groups according to glycosylated hemoglobin (HbA1c: G1≤7% and G2>7.0%. Resting heart rate (HR and RR interval (RRi were obtained and calculated by linear (Mean iRR; Mean HR; rMSSD; STD RR; LF; HF; LF/HF, TINN and RR Tri, and non-linear (SD1; SD2; DFα1; DFα2, Shannon entropy; ApEn; SampEn and CD methods of heart rate variability (HRV. Insulin, HOMA-IR, fasting glucose and HbA1c were obtained by blood tests.RESULTS: G2 (HbA1c≤7% showed lower values for the mean of iRR; STD RR; RR Tri, TINN, SD2, CD and higher mean HR when compared with G1 (HbA1c > 7%. Additionally, HbA1c correlated negatively with mean RRi (r=0.28, p=0.044; STD RR (r=0.33, p=0.017; RR Tri (r=-0.35, p=0.013, SD2 (r=-0.39, p=0.004 and positively with mean HR (r=0.28, p=0.045. Finally, fasting glucose correlated negatively with STD RR (r=-0.36, p=0.010; RR Tri (r=-0.36, p=0.010; TINN (r=-0.33, p=0.019 and SD2 (r=-0.42, p=0.002.CONCLUSION: We concluded that poor glycemic control is related to cardiac autonomic modulation indices in individuals with T2DM even if they do not present cardiovascular autonomic neuropathy.

  6. The dependence of the growth rate and meat content of young boars on semen parameters and conception rate.

    Science.gov (United States)

    Knecht, D; Jankowska-Mąkosa, A; Duziński, K

    2017-05-01

    Boars have a decisive impact on the progress in pig production, however, there is no recent information about the optimal growth parameters during the rearing period for modern breed later used in artificial insemination (AI) stations. Therefore, the objective of the research was to conduct semen parameter and conception rate analyses on the basis of growth rate and meat content assessments made during the rearing of AI boars of different genotypes. The study was carried out between 2010 and 2014 and included 184 boars in five breed combinations: 46 Polish Large White, 50 Polish Landrace, 27 Pietrain, 36 Duroc×Pietrain and 25 Hampshire×Pietrain. Boars were qualified by daily gains and meat content assessment (between 170 and 210 days of life). A total number of 38 272 ejaculates were examined (semen volume (ml), spermatozoa concentration (×106 ml-1), total number of spermatozoa (×109) and number of insemination doses from one ejaculate (n)). The fertility was determined by the conception rate (%). Semen volume, spermatozoa concentration and conception rate (PMeat content affected semen volume, number of insemination doses and conception rate (Pmeat content helps AI stations to increase the efficiency and economic profitability, and the number of insemination doses to increase by up to 300 doses/boar within a year. The analyses of growth parameters may help increase the efficiency and economic viability of AI stations.

  7. Periodic matrix population models: growth rate, basic reproduction number, and entropy.

    Science.gov (United States)

    Bacaër, Nicolas

    2009-10-01

    This article considers three different aspects of periodic matrix population models. First, a formula for the sensitivity analysis of the growth rate lambda is obtained that is simpler than the one obtained by Caswell and Trevisan. Secondly, the formula for the basic reproduction number R0 in a constant environment is generalized to the case of a periodic environment. Some inequalities between lambda and R0 proved by Cushing and Zhou are also generalized to the periodic case. Finally, we add some remarks on Demetrius' notion of evolutionary entropy H and its relationship to the growth rate lambda in the periodic case.

  8. ANALYSIS OF FACTORS WHICH AFFECTING THE ECONOMIC GROWTH

    Directory of Open Access Journals (Sweden)

    Suparna Wijaya

    2017-03-01

    Full Text Available High economic growth and sustainable process are main conditions for sustainability of economic country development. They are also become measures of the success of the country's economy. Factors which tested in this study are economic and non-economic factors which impacting economic development. This study has a goal to explain the factors that influence on macroeconomic Indonesia. It used linear regression modeling approach. The analysis result showed that Tax Amnesty, Exchange Rate, Inflation, and interest rate, they jointly can bring effect which amounted to 77.6% on economic growth whereas the remaining 22.4% is the influenced by other variables which not observed in this study. Keywords: tax amnesty, exchange rates, inflation, SBI and economic growth

  9. Physiological levels of nitrate support anoxic growth by denitrification of Pseudomonas aeruginosa at growth rates reported in cystic fibrosis lungs and sputum

    DEFF Research Database (Denmark)

    Line, Laura; Alhede, Morten; Kolpen, Mette

    2014-01-01

    denitrification. The growth rate of P. aeruginosa achieved by denitrification at physiological levels (~400 μM) of nitrate (NO(-) 3) is however, not known. Therefore, we have measured growth rates of anoxic cultures of PAO1 and clinical isolates (n = 12) in LB media supplemented with NO(-) 3 and found...... a significant increase of growth when supplementing PAO1 and clinical isolates with ≥150 μM NO(-) 3 and 100 μM NO(-) 3, respectively. An essential contribution to growth by denitrification was demonstrated by the inability to establish a significantly increased growth rate by a denitrification deficient Δnir...... of the four N-oxide reductases in PAO1 (Nar, Nir, Nor, Nos) further verified the engagement of denitrification, showing a transient increase in activation and expression and rapid consumption of NO(-) 3 followed by a transient increase of NO(-) 2. Growth rates obtained by denitrification in this study were...

  10. Microscopic Rate Constants of Crystal Growth from Molecular Dynamic Simulations Combined with Metadynamics

    Directory of Open Access Journals (Sweden)

    Dániel Kozma

    2012-01-01

    Full Text Available Atomistic simulation of crystal growth can be decomposed into two steps: the determination of the microscopic rate constants and a mesoscopic kinetic Monte Carlo simulation. We proposed a method to determine kinetic rate constants of crystal growth. We performed classical molecular dynamics on the equilibrium liquid/crystal interface of argon. Metadynamics was used to explore the free energy surface of crystal growth. A crystalline atom was selected at the interface, and it was displaced to the liquid phase by adding repulsive Gaussian potentials. The activation free energy of this process was calculated as the maximal potential energy density of the Gaussian potentials. We calculated the rate constants at different interfacial structures using the transition state theory. In order to mimic real crystallization, we applied a temperature difference in the calculations of the two opposite rate constants, and they were applied in kinetic Monte Carlo simulation. The novelty of our technique is that it can be used for slow crystallization processes, while the simple following of trajectories can be applied only for fast reactions. Our method is a possibility for determination of elementary rate constants of crystal growth that seems to be necessary for the long-time goal of computer-aided crystal design.

  11. Concurrent growth rate and transcript analyses reveal essential gene stringency in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Shan Goh

    Full Text Available BACKGROUND: Genes essential for bacterial growth are of particular scientific interest. Many putative essential genes have been identified or predicted in several species, however, little is known about gene expression requirement stringency, which may be an important aspect of bacterial physiology and likely a determining factor in drug target development. METHODOLOGY/PRINCIPAL FINDINGS: Working from the premise that essential genes differ in absolute requirement for growth, we describe silencing of putative essential genes in E. coli to obtain a titration of declining growth rates and transcript levels by using antisense peptide nucleic acids (PNA and expressed antisense RNA. The relationship between mRNA decline and growth rate decline reflects the degree of essentiality, or stringency, of an essential gene, which is here defined by the minimum transcript level for a 50% reduction in growth rate (MTL(50. When applied to four growth essential genes, both RNA silencing methods resulted in MTL(50 values that reveal acpP as the most stringently required of the four genes examined, with ftsZ the next most stringently required. The established antibacterial targets murA and fabI were less stringently required. CONCLUSIONS: RNA silencing can reveal stringent requirements for gene expression with respect to growth. This method may be used to validate existing essential genes and to quantify drug target requirement.

  12. Growth of sand whiff Citharichthys arenaceus and bay whiff Citharichthys spilopterus (pleuronectiformes: bothidae) in Puerto Rico (greater antilles) and North Carolina (USA), with comments on growth rate comparisons

    Science.gov (United States)

    Joyeux, Jean-Christophe; Miller, John M.; Aliaume, Catherine; Zerbi, Alfonso

    Sagittal otoliths from two bothid flatfish species ( Citharichthys arenaceus and C. spilopterus) collected in Puerto Rico were microstructurally examined and periodic increments counted. C. arenaceus length-at-age (33 to 246 days) data were best fitted by a Gompertz growth model whose parameters were estimated to be SL ∞ = 170 mm and K = 0.0166. Adult size is reached in less than one year. The peak period of hatching occurred in late spring, and settlement took place 39 days later. Due to a smaller age range (71 to 150 days), growth of C. spilopterus was described by a linear relationship with slope = 0.693 and intercept = -15.1 days. Hatching occurred in winter and spring. These two species showed no significant difference in age at settlement. After settlement, growth of C. spilopterus (0.69 mm·d -1 at 71 to 113 days old) was significantly slower than that of C. arenaceus (1.00 mm·d -1 at 71 to 113 days) possibly due to poorer environmental (abiotic or food-related) conditions during the dry, cool season (December-April). C. spilopterus from North Carolina, hatched in the same period, settled about two weeks older than in Puerto Rico. Growth after settlement was significantly slower in North Carolina (0.44 mm·d -1 at 71 to 113 days) than in Puerto Rico. Environmental conditions (including temperature), distance between spawning areas and settlement grounds, and/or food availability, might explain the dissimilarity in growth observed between the two geographic areas. We recommend absolute field growth to be compared by using growth rates obtained by deriving the growth curve formula.

  13. Facilitating control of fed-batch fermentation processes by monitoring the growth rates of saccharomyces cerevisiae

    NARCIS (Netherlands)

    Keulers, M.L.B.; Ariaans, L.J.J.M.; Soeterboek, R.; Giuseppin, M.

    1994-01-01

    In this paper we present a growth rate controller for a fed-batch bioprocess. An observer estimates the growth rate. The observer is based on knowledge about the stoichiometric relations of the process. Furthermore, the observer needs online measurements of the oxygen uptake rate and the

  14. Homogeneous shear turbulence – bypass concept via interplay of linear transient growth and nonlinear transverse cascade

    International Nuclear Information System (INIS)

    Mamatsashvili, George; Dong, Siwei; Jiménez, Javier; Khujadze, George; Chagelishvili, George; Foysi, Holger

    2016-01-01

    We performed direct numerical simulations of homogeneous shear turbulence to study the mechanism of the self-sustenance of subcritical turbulence in spectrally stable (constant) shear flows. For this purpose, we analyzed the turbulence dynamics in Fourier/wavenumber/spectral space based on the simulation data for the domain aspect ratio 1 : 1 : 1. Specifically, we examined the interplay of linear transient growth of Fourier harmonics and nonlinear processes. The transient growth of harmonics is strongly anisotropic in spectral space. This, in turn, leads to anisotropy of nonlinear processes in spectral space and, as a result, the main nonlinear process appears to be not a direct/inverse, but rather a transverse/angular redistribution of harmonics in Fourier space referred to as the nonlinear transverse cascade. It is demonstrated that the turbulence is sustained by the interplay of the linear transient, or nonmodal growth and the transverse cascade. This course of events reliably exemplifies the wellknown bypass scenario of subcritical turbulence in spectrally stable shear flows. These processes mainly operate at large length scales, comparable to the box size. Consequently, the central, small wavenumber area of Fourier space (the size of which is determined below) is crucial in the self-sustenance and is labeled the vital area. Outside the vital area, the transient growth and the transverse cascade are of secondary importance - Fourier harmonics are transferred to dissipative scales by the nonlinear direct cascade. The number of harmonics actively participating in the self-sustaining process (i.e., the harmonics whose energies grow more than 10% of the maximum spectral energy at least once during evolution) is quite large - it is equal to 36 for the considered box aspect ratio - and obviously cannot be described by low-order models. (paper)

  15. EFFECT OF SODIUM DODECYLBENZENESULFONIC ACID (SDBS ON THE GROWTH RATE AND MORPHOLOGY OF BORAX CRYSTAL

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available An investigation of the effect of sodium dodecylbenzenesulfonic acid (SDBS on both growth rate and morphology of borax crystal has been carried out.  This experiment was carried out at temperature of 25 °C and relative supersaturation of 0.21 and 0.74 under in situ cell optical microscopy method.  The result shows that SDBS inhibits the growth rate and changes the morphology of borax crystal.   Keywords: Borax; growth rate; crystallization, SDBS

  16. Numerical computation of the linear stability of the diffusion model for crystal growth simulation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.; Sorensen, D.C. [Rice Univ., Houston, TX (United States); Meiron, D.I.; Wedeman, B. [California Institute of Technology, Pasadena, CA (United States)

    1996-12-31

    We consider a computational scheme for determining the linear stability of a diffusion model arising from the simulation of crystal growth. The process of a needle crystal solidifying into some undercooled liquid can be described by the dual diffusion equations with appropriate initial and boundary conditions. Here U{sub t} and U{sub a} denote the temperature of the liquid and solid respectively, and {alpha} represents the thermal diffusivity. At the solid-liquid interface, the motion of the interface denoted by r and the temperature field are related by the conservation relation where n is the unit outward pointing normal to the interface. A basic stationary solution to this free boundary problem can be obtained by writing the equations of motion in a moving frame and transforming the problem to parabolic coordinates. This is known as the Ivantsov parabola solution. Linear stability theory applied to this stationary solution gives rise to an eigenvalue problem of the form.

  17. High Altitude Affects Nocturnal Non-linear Heart Rate Variability: PATCH-HA Study

    Directory of Open Access Journals (Sweden)

    Christopher J. Boos

    2018-04-01

    Full Text Available Background: High altitude (HA exposure can lead to changes in resting heart rate variability (HRV, which may be linked to acute mountain sickness (AMS development. Compared with traditional HRV measures, non-linear HRV appears to offer incremental and prognostic data, yet its utility and relationship to AMS have been barely examined at HA. This study sought to examine this relationship at terrestrial HA.Methods: Sixteen healthy British military servicemen were studied at baseline (800 m, first night and over eight consecutive nights, at a sleeping altitude of up to 3600 m. A disposable cardiac patch monitor was used, to record the nocturnal cardiac inter-beat interval data, over 1 h (0200–0300 h, for offline HRV assessment. Non-linear HRV measures included Sample entropy (SampEn, the short (α1, 4–12 beats and long-term (α2, 13–64 beats detrend fluctuation analysis slope and the correlation dimension (D2. The maximal rating of perceived exertion (RPE, during daily exercise, was assessed using the Borg 6–20 RPE scale.Results: All subjects completed the HA exposure. The average age of included subjects was 31.4 ± 8.1 years. HA led to a significant fall in SpO2 and increase in heart rate, LLS and RPE. There were no significant changes in the ECG-derived respiratory rate or in any of the time domain measures of HRV during sleep. The only notable changes in frequency domain measures of HRV were an increase in LF and fall in HFnu power at the highest altitude. Conversely, SampEn, SD1/SD2 and D2 all fell, whereas α1 and α2 increased (p < 0.05. RPE inversely correlated with SD1/SD2 (r = -0.31; p = 0.002, SampEn (r = -0.22; p = 0.03, HFnu (r = -0.27; p = 0.007 and positively correlated with LF (r = 0.24; p = 0.02, LF/HF (r = 0.24; p = 0.02, α1 (r = 0.32; p = 0.002 and α2 (r = 0.21; p = 0.04. AMS occurred in 7/16 subjects (43.8% and was very mild in 85.7% of cases. HRV failed to predict AMS.Conclusion: Non-linear HRV is more sensitive to the

  18. Linear calculations of edge current driven kink modes with BOUT++ code

    Energy Technology Data Exchange (ETDEWEB)

    Li, G. Q., E-mail: ligq@ipp.ac.cn; Xia, T. Y. [Institute of Plasma Physics, CAS, Hefei, Anhui 230031 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Snyder, P. B.; Turnbull, A. D. [General Atomics, San Diego, California 92186 (United States); Ma, C. H.; Xi, P. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); FSC, School of Physics, Peking University, Beijing 100871 (China)

    2014-10-15

    This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density.

  19. Linear calculations of edge current driven kink modes with BOUT++ code

    International Nuclear Information System (INIS)

    Li, G. Q.; Xia, T. Y.; Xu, X. Q.; Snyder, P. B.; Turnbull, A. D.; Ma, C. H.; Xi, P. W.

    2014-01-01

    This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density

  20. Generation and growth rates of nonlinear distortions in a traveling wave tube

    International Nuclear Information System (INIS)

    Woehlbier, John G.; Dobson, Ian; Booske, John H.

    2002-01-01

    The structure of a steady state multifrequency model of a traveling wave tube amplifier is exploited to describe the generation of intermodulation frequencies and calculate their growth rates. The model describes the evolution of Fourier coefficients of circuit and electron beam quantities and has the form of differential equations with quadratic nonlinearities. Intermodulation frequencies are sequentially generated by the quadratic nonlinearities in a series solution of the differential equations. A formula for maximum intermodulation growth rates is derived and compared to simulation results

  1. A linear model of population dynamics

    Science.gov (United States)

    Lushnikov, A. A.; Kagan, A. I.

    2016-08-01

    The Malthus process of population growth is reformulated in terms of the probability w(n,t) to find exactly n individuals at time t assuming that both the birth and the death rates are linear functions of the population size. The master equation for w(n,t) is solved exactly. It is shown that w(n,t) strongly deviates from the Poisson distribution and is expressed in terms either of Laguerre’s polynomials or a modified Bessel function. The latter expression allows for considerable simplifications of the asymptotic analysis of w(n,t).

  2. Linear growth and final height characteristics in adolescent females with anorexia nervosa.

    Directory of Open Access Journals (Sweden)

    Dalit Modan-Moses

    Full Text Available OBJECTIVE: Growth retardation is an established complication of anorexia nervosa (AN. However, findings concerning final height of AN patients are inconsistent. The aim of this study was to assess these phenomena in female adolescent inpatients with AN. METHODS: We retrospectively studied all 211 female adolescent AN patients hospitalized in an inpatient eating disorders department from 1/1/1987 to 31/12/99. Height and weight were assessed at admission and thereafter routinely during hospitalization and follow-up. Final height was measured in 69 patients 2-10 years after discharge. Pre-morbid height data was available in 29 patients. RESULTS: Patients' height standard deviation scores (SDS on admission (-0.285±1.0 and discharge (-0.271±1.02 were significantly (p<0.001 lower than expected in normal adolescents. Patients admitted at age ≤13 years, or less than 1 year after menarche, were more severely growth-impaired than patients admitted at an older age, (p = 0.03. Final height SDS, available for 69 patients, was -0.258±1.04, significantly lower than expected in a normal population (p = 0.04, and was more severely compromised in patients who were admitted less than 1 year from their menarche. In a subgroup of 29 patients with complete growth data (pre-morbid, admission, discharge, and final adult height, the pre-morbid height SDS was not significantly different from the expected (-0.11±1.1, whereas heights at the other time points were significantly (p = 0.001 lower (-0.56±1.2, -0.52±1.2, and -0.6±1.2, respectively. CONCLUSIONS: Our findings suggest that whereas the premorbid height of female adolescent AN patients is normal, linear growth retardation is a prominent feature of their illness. Weight restoration is associated with catch-up growth, but complete catch-up is often not achieved.

  3. Stiff mutant genes of Phycomyces target turgor pressure and wall mechanical properties to regulate elongation growth rate

    Directory of Open Access Journals (Sweden)

    Joseph K. E. Ortega

    2012-05-01

    Full Text Available Regulation of cell growth is paramount to all living organisms. In plants, algae and fungi, regulation of expansive growth of cells is required for development and morphogenesis. Also, many sensory responses of stage IVb sporangiophores of Phycomyces blakesleeanus are produced by regulating elongation growth rate (growth responses and differential elongation growth rate (tropic responses. Stiff mutant sporangiophores exhibit diminished tropic responses and are found to be defective in at least four genes; madD, madE, madF and madG. Prior experimental research suggests that the defective genes affect growth regulation, but this was not verified. All the growth of the single-celled stalk of the stage IVb sporangiophore occurs in a short region termed the growth zone. Prior experimental and theoretical research indicates that elongation growth rate of the stage IVb sporangiophore can be regulated by controlling the cell wall mechanical properties within the growth zone and the magnitude of the turgor pressure. A quantitative biophysical model for elongation growth rate is required to elucidate the relationship between wall mechanical properties and turgor pressure during growth regulation. In this study, it is hypothesized that the mechanical properties of the wall within the growth zone of stiff mutant sporangiophores are different compared to wild type. A biophysical equation for elongation growth rate is derived for fungal and plant cells with a growth zone. Two strains of stiff mutants are studied, C149 madD120 (- and C216 geo- (-. Experimental results demonstrate that turgor pressure is larger but irreversible deformation rates of the wall within the growth zone and growth zone length are smaller for stiff mutant sporangiophores compared to wild type. These findings explain the diminished tropic responses of the stiff mutant sporangiophores and suggest that the defective genes affect the amount of wall-building material delivered to the inner

  4. Spectral theories for linear differential equations

    International Nuclear Information System (INIS)

    Sell, G.R.

    1976-01-01

    The use of spectral analysis in the study of linear differential equations with constant coefficients is not only a fundamental technique but also leads to far-reaching consequences in describing the qualitative behaviour of the solutions. The spectral analysis, via the Jordan canonical form, will not only lead to a representation theorem for a basis of solutions, but will also give a rather precise statement of the (exponential) growth rates of various solutions. Various attempts have been made to extend this analysis to linear differential equations with time-varying coefficients. The most complete such extensions is the Floquet theory for equations with periodic coefficients. For time-varying linear differential equations with aperiodic coefficients several authors have attempted to ''extend'' the Foquet theory. The precise meaning of such an extension is itself a problem, and we present here several attempts in this direction that are related to the general problem of extending the spectral analysis of equations with constant coefficients. The main purpose of this paper is to introduce some problems of current research. The primary problem we shall examine occurs in the context of linear differential equations with almost periodic coefficients. We call it ''the Floquet problem''. (author)

  5. Growth and Zeros of Meromorphic Solutions to Second-Order Linear Differential Equations

    Directory of Open Access Journals (Sweden)

    Maamar Andasmas

    2016-04-01

    Full Text Available The main purpose of this article is to investigate the growth of meromorphic solutions to homogeneous and non-homogeneous second order linear differential equations f00+Af0+Bf = F, where A(z, B (z and F (z are meromorphic functions with finite order having only finitely many poles. We show that, if there exist a positive constants σ > 0, α > 0 such that |A(z| ≥ eα|z|σ as |z| → +∞, z ∈ H, where dens{|z| : z ∈ H} > 0 and ρ = max{ρ(B, ρ(F} < σ, then every transcendental meromorphic solution f has an infinite order. Further, we give some estimates of their hyper-order, exponent and hyper-exponent of convergence of distinct zeros.

  6. Growth-Rate Dependent Regulation of tRNA Level and Charging in Bacillus licheniformis.

    Science.gov (United States)

    Ferro, Iolanda; Liebeton, Klaus; Ignatova, Zoya

    2017-10-13

    Cellular growth crucially depends on protein synthesis and the abundance of translational components. Among them, aminoacyl-tRNAs play a central role in biosynthesis and shape the kinetics of mRNA translation, thus influencing protein production. Here, we used microarray-based approaches to determine the charging levels and tRNA abundance of Bacillus licheniformis. We observed an interesting cross-talk among tRNA expression, charging pattern, and growth rate. For a large subset of tRNAs, we found a co-regulated and augmented expression at high growth rate. Their tRNA aminoacylation level is kept relatively constant through riboswitch-regulated expression of the cognate aminoacyl-tRNA-synthetase (AARS). We show that AARSs with putative riboswitch-controlled expression are those charging tRNAs with amino acids which disfavor cell growth when individually added to the nutrient medium. Our results suggest that the riboswitch-regulated AARS expression in B. licheniformis is a powerful mechanism not only to maintain a constant ratio of aminoacyl-tRNA independent of the growth rate but concomitantly to control the intracellular level of free amino acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Nonlinear Growth Curves in Developmental Research

    Science.gov (United States)

    Grimm, Kevin J.; Ram, Nilam; Hamagami, Fumiaki

    2011-01-01

    Developmentalists are often interested in understanding change processes and growth models are the most common analytic tool for examining such processes. Nonlinear growth curves are especially valuable to developmentalists because the defining characteristics of the growth process such as initial levels, rates of change during growth spurts, and asymptotic levels can be estimated. A variety of growth models are described beginning with the linear growth model and moving to nonlinear models of varying complexity. A detailed discussion of nonlinear models is provided, highlighting the added insights into complex developmental processes associated with their use. A collection of growth models are fit to repeated measures of height from participants of the Berkeley Growth and Guidance Studies from early childhood through adulthood. PMID:21824131

  8. Data compilation of respiration, feeding, and growth rates of marine pelagic organisms

    DEFF Research Database (Denmark)

    2013-01-01

    's adaptation to the environment, with consequently less universal mass scaling properties. Data on body mass, maximum ingestion and clearance rates, respiration rates and maximum growth rates of animals living in the ocean epipelagic were compiled from the literature, mainly from original papers but also from...

  9. Additional Common Bean in the Diet of Malawian Children Does Not Affect Linear Growth, but Reduces Intestinal Permeability.

    Science.gov (United States)

    Agapova, Sophia E; Stephenson, Kevin B; Divala, Oscar; Kaimila, Yankho; Maleta, Kenneth M; Thakwalakwa, Chrissie; Ordiz, M Isabel; Trehan, Indi; Manary, Mark J

    2018-02-01

    Chronic malnutrition, as manifested by linear growth faltering, is pervasive among rural African children. Improvements in complementary feeding may decrease the burden of environmental enteric dysfunction (EED) and thus improve growth in children during the critical first 1000 d of development. We tested the hypothesis that systematically including common bean or cowpea into complementary feeding would reduce EED and growth faltering among children in rural Malawi. This was a double-blind clinical trial in which children 12-23 mo of age were randomly assigned to receive complementary feeding with 1 of 3 foods: roasted cowpea or common bean flour, or an isoenergetic amount of corn-soy blend as a control food for 48 wk. Children aged 12-23 mo received 155 kcal/d and thereafter until 35 mo received 200 kcal/d. The primary outcomes were change in length-for-age z score (LAZ) and improvements in a biomarker of EED, the percentage of lactulose (%L) excreted as part of the lactulose:mannitol dual-sugar absorption test. Anthropometric measurements and urinary %L excretion were compared between the 2 intervention groups and the control group separately with the use of linear mixed model analyses for repeated measures. A total of 331 children completed the clinical trial. Compliance with the study interventions was excellent, with >90% of the intervention flour consumed as intended. No significant effects on LAZ, change in LAZ, or weight-for-length z score were observed due to either intervention legume, compared to the control. %L was reduced with common bean consumption (effect estimate was -0.07 percentage points of lactulose, P = 0.0007). The lactulose:mannitol test was not affected by the legume intervention. The addition of common bean to complementary feeding of rural Malawian children during the second year of life led to an improvement in a biomarker of gut health, although this did not directly translate into improved linear growth. This trial was registered at

  10. Effects of root radius, stress, crack growth and rate on fracture instability

    Energy Technology Data Exchange (ETDEWEB)

    McClintock, F A

    1965-01-01

    Of various criteria for fracture at the root of a notch, the energy, local stress, and displacement criteria have limited validity. More appropriate is the history of both stress and strain over a small region ahead of the crack, as required for fracture by the coalescence of holes. Expressions are given for crack initiation, growth, and subsequent instability in anti-plane strain of a nonhardening material. Instability is shown to depend primarily on those strain increments arising from crack growth at constant load rather than on those from increasing load at constant crack length. Thus final instability conditions are similar for single and double- ended cracks, round notches, and cracks cut under constant load. Round notches may give instability, restabilization and final instability. The growth and coalescence of holes in front of a crack in a linearly viscous material is studied for both tensile and anti-plant-strain cracks. The absence of residual strain eliminates instability, but the crack continually accelerates. (26 refs.)

  11. Thermal effects on growth and respiration rates of the mayfly, Dolania americana (ephemeroptera)

    International Nuclear Information System (INIS)

    Harvey, R.S.

    1975-01-01

    The mayfly Dolania Americana, common in the sand of Upper Three Runs Creek, Savannah River Plant, was studied to determine the effects of seasonal changes in temperature on population growth rates and to determine the effects of slight elevations in water temperature on respiration rates of this benthic species. Growth of the population increased with stream temperature until peak emergence of adults in June and July. There was a strong inverse correlation between body weight and respiration rates of immature nymphs. Respiration rates at 2.5, 5, and 10 0 C above ambient creekwater temperatures were not significantly higher than those measured at ambient creekwater temperatures. (auth)

  12. Investigating the asymmetric relationship between inflation-output growth exchange rate changes

    Science.gov (United States)

    Chu, Jenq Fei; Sek, Siok Kun

    2017-08-01

    The relationship between inflation-output growth or output variation has long been studied. In this study, we extend the investigation under two exchange rate flexibility/regime in four Asian countries (Indonesia, Korea, Philippines and Thailand) that have experienced drastic exchange rate regime changes aftermath the financial crisis of 1997. These countries have switched from fixed/rigid exchange rate regime to flexible exchange rate and inflation targeting (IT) regime after the crisis. Our main objective is to compare the inflation-output trade-off relationship in the pre-IT and post-IT periods as a tool to evaluate the efficiency of monetary policy. A nonlinear autoregressive distributed lags (NARDL) model is applied to capture the asymmetric effects of exchange rate changes (increases and decreases). The data ranging from 1981M1 onwards till 2016M3. Our results show that exchange rate has asymmetric effect on inflation both short-run and long-run with larger impact in the post-IT period under flexible regime. Depreciation of exchange rate has leads to higher inflation. Furthermore, we find evidences on the relationship between inflation and growth in both short-run and long-run, but the trade-off only detected in the short run both in the pre- and post-IT periods.

  13. Hypocoercivity for linear kinetic equations conserving mass

    KAUST Repository

    Dolbeault, Jean; Mouhot, Clé ment; Schmeiser, Christian

    2015-01-01

    We develop a new method for proving hypocoercivity for a large class of linear kinetic equations with only one conservation law. Local mass conservation is assumed at the level of the collision kernel, while transport involves a confining potential, so that the solution relaxes towards a unique equilibrium state. Our goal is to evaluate in an appropriately weighted $ L^2$ norm the exponential rate of convergence to the equilibrium. The method covers various models, ranging from diffusive kinetic equations like Vlasov-Fokker-Planck equations, to scattering models or models with time relaxation collision kernels corresponding to polytropic Gibbs equilibria, including the case of the linear Boltzmann model. In this last case and in the case of Vlasov-Fokker-Planck equations, any linear or superlinear growth of the potential is allowed. - See more at: http://www.ams.org/journals/tran/2015-367-06/S0002-9947-2015-06012-7/#sthash.ChjyK6rc.dpuf

  14. Hypocoercivity for linear kinetic equations conserving mass

    KAUST Repository

    Dolbeault, Jean

    2015-02-03

    We develop a new method for proving hypocoercivity for a large class of linear kinetic equations with only one conservation law. Local mass conservation is assumed at the level of the collision kernel, while transport involves a confining potential, so that the solution relaxes towards a unique equilibrium state. Our goal is to evaluate in an appropriately weighted $ L^2$ norm the exponential rate of convergence to the equilibrium. The method covers various models, ranging from diffusive kinetic equations like Vlasov-Fokker-Planck equations, to scattering models or models with time relaxation collision kernels corresponding to polytropic Gibbs equilibria, including the case of the linear Boltzmann model. In this last case and in the case of Vlasov-Fokker-Planck equations, any linear or superlinear growth of the potential is allowed. - See more at: http://www.ams.org/journals/tran/2015-367-06/S0002-9947-2015-06012-7/#sthash.ChjyK6rc.dpuf

  15. Linear transceiver design for nonorthogonal amplify-and-forward protocol using a bit error rate criterion

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2014-04-01

    The ever growing demand of higher data rates can now be addressed by exploiting cooperative diversity. This form of diversity has become a fundamental technique for achieving spatial diversity by exploiting the presence of idle users in the network. This has led to new challenges in terms of designing new protocols and detectors for cooperative communications. Among various amplify-and-forward (AF) protocols, the half duplex non-orthogonal amplify-and-forward (NAF) protocol is superior to other AF schemes in terms of error performance and capacity. However, this superiority is achieved at the cost of higher receiver complexity. Furthermore, in order to exploit the full diversity of the system an optimal precoder is required. In this paper, an optimal joint linear transceiver is proposed for the NAF protocol. This transceiver operates on the principles of minimum bit error rate (BER), and is referred as joint bit error rate (JBER) detector. The BER performance of JBER detector is superior to all the proposed linear detectors such as channel inversion, the maximal ratio combining, the biased maximum likelihood detectors, and the minimum mean square error. The proposed transceiver also outperforms previous precoders designed for the NAF protocol. © 2002-2012 IEEE.

  16. Rising CO2 interacts with growth light and growth rate to alter photosystem II photoinactivation of the coastal diatom Thalassiosira pseudonana.

    Directory of Open Access Journals (Sweden)

    Gang Li

    Full Text Available We studied the interactive effects of pCO(2 and growth light on the coastal marine diatom Thalassiosira pseudonana CCMP 1335 growing under ambient and expected end-of-the-century pCO(2 (750 ppmv, and a range of growth light from 30 to 380 µmol photons·m(-2·s(-1. Elevated pCO(2 significantly stimulated the growth of T. pseudonana under sub-saturating growth light, but not under saturating to super-saturating growth light. Under ambient pCO(2 susceptibility to photoinactivation of photosystem II (σ(i increased with increasing growth rate, but cells growing under elevated pCO(2 showed no dependence between growth rate and σ(i, so under high growth light cells under elevated pCO(2 were less susceptible to photoinactivation of photosystem II, and thus incurred a lower running cost to maintain photosystem II function. Growth light altered the contents of RbcL (RUBISCO and PsaC (PSI protein subunits, and the ratios among the subunits, but there were only limited effects on these and other protein pools between cells grown under ambient and elevated pCO(2.

  17. Using wavelength-normalized optical spectroscopy to improve the accuracy of bacteria growth rate quantification

    Science.gov (United States)

    McBirney, Samantha E.; Trinh, Kristy; Wong-Beringer, Annie; Armani, Andrea M.

    2017-02-01

    One of the fundamental analytical measurements performed in microbiology is monitoring and characterizing cell concentration in culture media. Measurement error will give rise to reproducibility problems in a wide range of applications, from biomanufacturing to basic research. Therefore, it is critical that the generated results are consistent. Single wavelength optical density (OD) measurements have become the preferred approach. Here, we compare the conventional OD600 technique with a multi-wavelength normalized scattering optical spectroscopy method to measure the growth rates of Pseudomonas aeruginosa and Staphylococcus aureus, two of the leading nosocomial pathogens with proven abilities to develop resistance. The multi-wavelength normalization process minimizes the impact of bacteria byproducts and environmental noise on the signal, thereby accurately quantifying growth rates with high fidelity at low concentrations. In contrast, due to poor absorbance and scattering at 600 nm, the classic OD600 measurement method is able to detect bacteria but cannot quantify the growth rate reliably. Our wavelength-normalization protocol to detect bacteria growth rates can be readily and easily adopted by research labs, given that it only requires the use of a standard spectrophotometer and implementation of straightforward data analysis. Measuring and monitoring bacteria growth rates play a critical role in a wide range of settings, spanning from therapeutic design and development to diagnostics and disease prevention. Having a full understanding of the growth cycles of bacteria known to cause severe infections and diseases will lead to a better understanding of the pathogenesis of these illnesses, leading to better treatment and, ultimately, the development of a cure.

  18. Radiosensitivity of the swiss-rap mouse as a function of its growth rate

    International Nuclear Information System (INIS)

    Legeay, G.; Glas, J.F.

    1969-01-01

    The results of an exhaustive study of the age dependence of the radiosensitivity of female Swiss-Rap mice are given. A close relationship of radiosensitivity versus age could not be brought out, whereas the weekly growth rate could be accurately related to radiosensitivity. Thus, the latter should be studied when a strain is to be used for biological experiments, as the rates of growth are different with the strains. (author) [fr

  19. Effect of temperature on sulphate reduction, growth rate and growth yield in five psychrophilic sulphate-reducing bacteria from Arctic sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB

    1999-01-01

    and T(opt). For strains LSv21 and LSv514, however, growth yields were highest at the lowest temperatures, around 0 degrees C. The results indicate that psychrophilic sulphate-reducing bacteria are specially adapted to permanently low temperatures by high relative growth rates and high growth yields......Five psychrophilic sulphate-reducing bacteria (strains ASv26, LSv21, PSv29, LSv54 and LSv514) isolated from Arctic sediments were examined for their adaptation to permanently low temperatures, All strains grew at -1.8 degrees C, the freezing point of sea water, but their optimum temperature...... for growth (T(opt)) were 7 degrees C (PSv29), 10 degrees C (ASv26, LSv54) and 18 degrees C (LSv21, LSv514), Although T(opt) was considerably above the in situ temperatures of their habitats (-1.7 degrees C and 2.6 degrees C), relative growth rates were still high at 0 degrees C, accounting for 25...

  20. Temperature Effects on the Growth Rates and Photosynthetic Activities of Symbiodinium Cells

    Directory of Open Access Journals (Sweden)

    Widiastuti Karim

    2015-06-01

    Full Text Available Coral bleaching is caused by environmental stress and susceptibility to bleaching stress varies among types of coral. The physiological properties of the algal symbionts (Symbiodinium spp., especially extent of damage to PSII and its repair capacity, contribute importantly to this variability in stress susceptibility. The objective of the present study was to investigate the relationship between the growth rates and photosynthetic activities of six cultured strains of Symbiodinium spp. (clades A, B, C, D, and F at elevated temperature (33 °C. We also observed the recovery of photodamaged-PSII in the presence or absence of a chloroplast protein synthesis inhibitor (lincomycin. The growth rates and photochemical efficiencies of PSII (Fv/Fm decreased in parallel at high temperature in thermally sensitive strains, B-K100 (clade B followed by culture name and A-Y106, but not in thermally tolerant strains, F-K102 and D-K111. In strains A-KB8 and C-Y103, growth declined markedly at high temperature, but Fv/Fm decreased only slightly. These strains may reallocate energy from growth to the repair of damaged photosynthetic machineries or protection pathways. Alternatively, since recoveries of photo-damaged PSII at 33 °C were modest in strains A-KB8 and C-Y103, thermal stressing of other metabolic pathways may have reduced growth rates in these two strains. This possibility should be explored in future research efforts.

  1. [Comparison of application of Cochran-Armitage trend test and linear regression analysis for rate trend analysis in epidemiology study].

    Science.gov (United States)

    Wang, D Z; Wang, C; Shen, C F; Zhang, Y; Zhang, H; Song, G D; Xue, X D; Xu, Z L; Zhang, S; Jiang, G H

    2017-05-10

    We described the time trend of acute myocardial infarction (AMI) from 1999 to 2013 in Tianjin incidence rate with Cochran-Armitage trend (CAT) test and linear regression analysis, and the results were compared. Based on actual population, CAT test had much stronger statistical power than linear regression analysis for both overall incidence trend and age specific incidence trend (Cochran-Armitage trend P valuelinear regression P value). The statistical power of CAT test decreased, while the result of linear regression analysis remained the same when population size was reduced by 100 times and AMI incidence rate remained unchanged. The two statistical methods have their advantages and disadvantages. It is necessary to choose statistical method according the fitting degree of data, or comprehensively analyze the results of two methods.

  2. Quantification of dendritic and axonal growth after injury to the auditory system of the adult cricket Gryllus bimaculatus

    Directory of Open Access Journals (Sweden)

    Alexandra ePfister

    2013-08-01

    Full Text Available Dendrite and axon growth and branching during development are regulated by a complex set of intracellular and external signals. However, the cues that maintain or influence adult neuronal morphology are less well understood. Injury and deafferentation tend to have negative effects on adult nervous systems. An interesting example of injury-induced compensatory growth is seen in the cricket, Gryllus bimaculatus. After unilateral loss of an ear in the adult cricket, auditory neurons within the central nervous system sprout to compensate for the injury. Specifically, after being deafferented, ascending neurons (AN-1 and AN-2 send dendrites across the midline of the prothoracic ganglion where they receive input from auditory afferents that project through the contralateral auditory nerve (N5. Deafferentation also triggers contralateral N5 axonal growth. In this study, we quantified AN dendritic and N5 axonal growth at 30 hours, as well as at 3, 5, 7, 14 and 20 days after deafferentation in adult crickets. Significant differences in the rates of dendritic growth between males and females were noted. In females, dendritic growth rates were non-linear; a rapid burst of dendritic extension in the first few days was followed by a plateau reached at 3 days after deafferentation. In males, however, dendritic growth rates were linear, with dendrites growing steadily over time and reaching lengths, on average, twice as long as in females. On the other hand, rates of N5 axonal growth showed no significant sexual dimorphism and were linear. Within each animal, the growth rates of dendrites and axons were not correlated, indicating that independent factors likely influence dendritic and axonal growth in response to injury in this system. Our findings provide a basis for future study of the cellular features that allow differing dendrite and axon growth patterns as well as sexually dimorphic dendritic growth in response to deafferentation.

  3. Constant savings rates and quasi-arithmetic population growth under exhaustible resource constraints

    NARCIS (Netherlands)

    Asheim, G.B.; Buchholz, W.; Hartwick, J.M.; Mitra, T.; Withagen, C.A.A.M.

    2007-01-01

    In the Dasgupta–Heal–Solow–Stiglitz (DHSS) model of capital accumulation and resource depletion we show the following equivalence: if an efficient path has constant (gross and net of population growth) savings rates, then population growth must be quasi-arithmetic and the path is a maximin or a

  4. Nucleation and growth kinetics of zirconium hydroxide by precipitation with ammonium hydroxide

    International Nuclear Information System (INIS)

    Carleson, T.E.; Chipman, N.A.

    1987-01-01

    The results of a study of the nucleation and growth kinetics of the precipitation of zirconium hydroxide from the reaction of hexafluorozirconate solution with ammonium hydroxide are reported. The McCabe linear growth rate model was used to correlate the results. The growth rate decreased with residence time and supersaturation for studies with 7 residence times (3.5 - 90 minutes and two supersaturation ratios (0.03 - 0.04, and 0.4). The nucleation rate increased with residence time and supersaturation. A negative kinetic order of nucleation was observed that may be due to the inhibition of particle growth by adsorption of reacting species on the crystal surfaces

  5. Ant Larval Demand Reduces Aphid Colony Growth Rates in an Ant-Aphid Interaction

    Directory of Open Access Journals (Sweden)

    James M. Cook

    2012-02-01

    Full Text Available Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used and previous diet (sugar only or sugar and protein. We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes.

  6. Re-alimentation in harbor seal pups: effects on the somatotropic axis and growth rate.

    Science.gov (United States)

    Richmond, Julie P; Norris, Tenaya; Zinn, Steven A

    2010-01-15

    The metabolic hormones, growth hormone (GH) and insulin-like growth factor (IGF)-I, together with IGF binding proteins (IGFBP), have been well studied in domestic species and are the primary components of the somatotropic axis. This hormone axis is responsive to nutrient intake, associated with growth rate, and accretion of protein and adipose. However, this relationship has not been evaluated in species that rely heavily on adipose stores for survival, such as pinnipeds. The primary objectives of this research were to investigate the response of the somatotropic axis to reduced nutrient intake and re-alimentation in rehabilitated harbor seal pups, and to assess if these hormones are related to nutritional status and growth rate in harbor seals. Stranded harbor seal pups (n=24) arrived at the rehabilitation facility very thin after fasting for several days (nutritional nadir). Throughout rehabilitation nutrient intake increased and pups gained mass and body condition. Concentrations of GH and IGFBP-2 decreased with re-alimentation, while IGF-I and IGFBP-3 concentrations increased. Overall, GH and IGFBP-2 were negatively associated and IGF-I and IGFBP-3 were positively associated with growth rate and increased body condition of harbor sea pups. Further, the magnitude of the growth response was related to the magnitude in response of the somatotropic axis to varied levels of intake. These data suggest that multiple components of the somatotropic axis may be used to assess the energy status of individuals and may also provide information on the level of feed intake that is predictive of growth rate.

  7. Two Aspects of the Simplex Model: Goodness of Fit to Linear Growth Curve Structures and the Analysis of Mean Trends.

    Science.gov (United States)

    Mandys, Frantisek; Dolan, Conor V.; Molenaar, Peter C. M.

    1994-01-01

    Studied the conditions under which the quasi-Markov simplex model fits a linear growth curve covariance structure and determined when the model is rejected. Presents a quasi-Markov simplex model with structured means and gives an example. (SLD)

  8. Experimental study of linear and nonlinear regimes of density-driven instabilities induced by CO{sub 2} dissolution in water

    Energy Technology Data Exchange (ETDEWEB)

    Outeda, R.; D' Onofrio, A. [Grupo de Medios Porosos, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, C1063ACV Buenos Aires (Argentina); El Hasi, C.; Zalts, A. [Instituto de Ciencias, Universidad Nacional General Sarmiento, J. M. Gutiérrez 1150, B1613GSX, Los Polvorines, Provincia de Buenos Aires (Argentina)

    2014-03-15

    Density driven instabilities produced by CO{sub 2} (gas) dissolution in water containing a color indicator were studied in a Hele Shaw cell. The images were analyzed and instability patterns were characterized by mixing zone temporal evolution, dispersion curves, and the growth rate for different CO{sub 2} pressures and different color indicator concentrations. The results obtained from an exhaustive analysis of experimental data show that this system has a different behaviour in the linear regime of the instabilities (when the growth rate has a linear dependence with time), from the nonlinear regime at longer times. At short times using a color indicator to see the evolution of the pattern, the images show that the effects of both the color indicator and CO{sub 2} pressure are of the same order of magnitude: The growth rates are similar and the wave numbers are in the same range (0–30 cm{sup −1}) when the system is unstable. Although in the linear regime the dynamics is affected similarly by the presence of the indicator and CO{sub 2} pressure, in the nonlinear regime, the influence of the latter is clearly more pronounced than the effects of the color indicator.

  9. The daily weight gain, growth rate and length-weight relationships of ...

    African Journals Online (AJOL)

    The daily weight gain, growth rate and length-weight relationships of Clarias gariepinus, Heterobranchus longifilis and their reciprocal hybrids (Pisces: Clariidae) reared under ambient environmental conditions.

  10. Intrinsic suppression of turbulence in linear plasma devices

    Science.gov (United States)

    Leddy, J.; Dudson, B.

    2017-12-01

    Plasma turbulence is the dominant transport mechanism for heat and particles in magnetised plasmas in linear devices and tokamaks, so the study of turbulence is important in limiting and controlling this transport. Linear devices provide an axial magnetic field that serves to confine a plasma in cylindrical geometry as it travels along the magnetic field from the source to the strike point. Due to perpendicular transport, the plasma density and temperature have a roughly Gaussian radial profile with gradients that drive instabilities, such as resistive drift-waves and Kelvin-Helmholtz. If unstable, these instabilities cause perturbations to grow resulting in saturated turbulence, increasing the cross-field transport of heat and particles. When the plasma emerges from the source, there is a time, {τ }\\parallel , that describes the lifetime of the plasma based on parallel velocity and length of the device. As the plasma moves down the device, it also moves azimuthally according to E × B and diamagnetic velocities. There is a balance point in these parallel and perpendicular times that sets the stabilisation threshold. We simulate plasmas with a variety of parallel lengths and magnetic fields to vary the parallel and perpendicular lifetimes, respectively, and find that there is a clear correlation between the saturated RMS density perturbation level and the balance between these lifetimes. The threshold of marginal stability is seen to exist where {τ }\\parallel ≈ 11{τ }\\perp . This is also associated with the product {τ }\\parallel {γ }* , where {γ }* is the drift-wave linear growth rate, indicating that the instability must exist for roughly 100 times the growth time for the instability to enter the nonlinear growth phase. We explore the root of this correlation and the implications for linear device design.

  11. On the relationship between tumour growth rate and survival in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Hitesh B. Mistry

    2017-11-01

    Full Text Available A recurrent question within oncology drug development is predicting phase III outcome for a new treatment using early clinical data. One approach to tackle this problem has been to derive metrics from mathematical models that describe tumour size dynamics termed re-growth rate and time to tumour re-growth. They have shown to be strong predictors of overall survival in numerous studies but there is debate about how these metrics are derived and if they are more predictive than empirical end-points. This work explores the issues raised in using model-derived metric as predictors for survival analyses. Re-growth rate and time to tumour re-growth were calculated for three large clinical studies by forward and reverse alignment. The latter involves re-aligning patients to their time of progression. Hence, it accounts for the time taken to estimate re-growth rate and time to tumour re-growth but also assesses if these predictors correlate to survival from the time of progression. I found that neither re-growth rate nor time to tumour re-growth correlated to survival using reverse alignment. This suggests that the dynamics of tumours up until disease progression has no relationship to survival post progression. For prediction of a phase III trial I found the metrics performed no better than empirical end-points. These results highlight that care must be taken when relating dynamics of tumour imaging to survival and that bench-marking new approaches to existing ones is essential.

  12. Inhibition linearizes firing rate responses in human motor units: implications for the role of persistent inward currents.

    Science.gov (United States)

    Revill, Ann L; Fuglevand, Andrew J

    2017-01-01

    rate profiles were best fitted by rising exponential functions. With stimulation, however, firing rate profiles were best fitted with linear functions or with less steeply rising exponentials. Firing rate profiles for the descending phases of the contractions were best fitted with linear functions for both control and stimulation conditions. These results seem consistent with the idea that PICs contribute to non-linear firing rate profiles during ascending but not descending phases of contractions. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  13. Effects of void anisotropy on the ignition and growth rates of energetic materials

    Science.gov (United States)

    Rai, Nirmal Kumar; Sen, Oishik; Udaykumar, H. S.

    2017-06-01

    Initiation of heterogeneous energetic materials is thought to occur at hot spots; reaction fronts propagate from sites of such hot spots into the surrounding material resulting in complete consumption of the material. Heterogeneous materials, such as plastic bonded explosives (PBXs) and pressed materials contain numerous voids, defects and interfaces at which hot spots can occur. Amongst the various mechanisms of hot spot formation, void collapse is considered to be the predominant one in the high strain rate loading conditions. It is established in the past the shape of the voids has a significant effect on the initiation behavior of energetic materials. In particular, void aspect ratio and orientations play an important role in this regard. This work aims to quantify the effects of void aspect ratio and orientation on the ignition and growth rates of chemical reaction from the hot spot. A wide range of aspect ratio and orientations is considered to establish a correlation between the ignition and growth rates and the void morphology. The ignition and growth rates are obtained from high fidelity reactive meso-scale simulations. The energetic material considered in this work is HMX and Tarver McGuire HMX decomposition model is considered to capture the reaction mechanism of HMX. The meso-scale simulations are performed using a Cartesian grid based Eulerian solver SCIMITAR3D. The void morphology is shown to have a significant effect on the ignition and growth rates of HMX.

  14. Constant Growth Rate Can Be Supported by Decreasing Energy Flux and Increasing Aerobic Glycolysis

    Directory of Open Access Journals (Sweden)

    Nikolai Slavov

    2014-05-01

    Full Text Available Fermenting glucose in the presence of enough oxygen to support respiration, known as aerobic glycolysis, is believed to maximize growth rate. We observed increasing aerobic glycolysis during exponential growth, suggesting additional physiological roles for aerobic glycolysis. We investigated such roles in yeast batch cultures by quantifying O2 consumption, CO2 production, amino acids, mRNAs, proteins, posttranslational modifications, and stress sensitivity in the course of nine doublings at constant rate. During this course, the cells support a constant biomass-production rate with decreasing rates of respiration and ATP production but also decrease their stress resistance. As the respiration rate decreases, so do the levels of enzymes catalyzing rate-determining reactions of the tricarboxylic-acid cycle (providing NADH for respiration and of mitochondrial folate-mediated NADPH production (required for oxidative defense. The findings demonstrate that exponential growth can represent not a single metabolic/physiological state but a continuum of changing states and that aerobic glycolysis can reduce the energy demands associated with respiratory metabolism and stress survival.

  15. Human disturbance influences reproductive success and growth rate in California sea lions (Zalophus californianus.

    Directory of Open Access Journals (Sweden)

    Susannah S French

    Full Text Available The environment is currently undergoing changes at both global (e.g., climate change and local (e.g., tourism, pollution, habitat modification scales that have the capacity to affect the viability of animal and plant populations. Many of these changes, such as human disturbance, have an anthropogenic origin and therefore may be mitigated by management action. To do so requires an understanding of the impact of human activities and changing environmental conditions on population dynamics. We investigated the influence of human activity on important life history parameters (reproductive rate, and body condition, and growth rate of neonate pups for California sea lions (Zalophus californianus in the Gulf of California, Mexico. Increased human presence was associated with lower reproductive rates, which translated into reduced long-term population growth rates and suggested that human activities are a disturbance that could lead to population declines. We also observed higher body growth rates in pups with increased exposure to humans. Increased growth rates in pups may reflect a density dependent response to declining reproductive rates (e.g., decreased competition for resources. Our results highlight the potentially complex changes in life history parameters that may result from human disturbance, and their implication for population dynamics. We recommend careful monitoring of human activities in the Gulf of California and emphasize the importance of management strategies that explicitly consider the potential impact of human activities such as ecotourism on vertebrate populations.

  16. Enhancement of wave growth for warm plasmas with a high-energy tail distribution

    Science.gov (United States)

    Thorne, Richard M.; Summers, Danny

    1991-01-01

    The classical linear theory of electromagnetic wave growth in a warm plasma is considered for waves propagating parallel to a uniform ambient magnetic field. Wave-growth rates are calculated for ion-driven right-hand mode waves for Kappa and Maxwellian particle distribution functions and for various values of the spectral index, the temperature anisotropy, and the ratio of plasma pressure to magnetic pressure appropriate to the solar wind. When the anisotropy is low the wave growth is limited to frequencies below the proton gyrofrequency and the growth rate increases dramatically as the spectral index is reduced. The growth rate for any Kappa distribution greatly exceeds that for a Maxwellian with the same bulk properties. For large thermal anisotropy the growth rate from either distribution is greatly enhanced. The growth rates from a Kappa distribution are generally larger than for a Maxwellian distribution, and significant wave growth occurs over a broader range of frequencies.

  17. Higher Growth Rate of Branch Duct Intraductal Papillary Mucinous Neoplasms Associates With Worrisome Features.

    Science.gov (United States)

    Kolb, Jennifer M; Argiriadi, Pamela; Lee, Karen; Liu, Xiaoyu; Bagiella, Emilia; Lucas, Aimee L; Kim, Michelle Kang; Kumta, Nikhil A; Nagula, Satish; Sarpel, Umut; DiMaio, Christopher J

    2018-03-11

    For patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs, cysts), it is a challenge to identify those at high risk for malignant lesions. We sought to identify factors associated with development of pancreatic cancer, focusing on neoplasm growth rate. We performed a retrospective study of 189 patients with BD-IPMNs who underwent at least 2 contrast-enhanced cross-sectional imaging studies, 1 year or more apart, at a tertiary referral center from January 2003 through 2013. Patients with cysts that had Fukuoka worrisome or high-risk features were excluded. Two radiologists reviewed all images. Cyst size was recorded at the initial and final imaging studies and growth rate was calculated. We collected patient demographic data, cyst characteristics, and clinical outcomes; univariate logistic regression models were used to determine the odds of developing worrisome features. The primary outcomes were to determine growth rate of low-risk BD-IPMNs and to assess whether cyst growth rate correlates high-risk features of IPMNs. Based on image analyses, cysts were initially a median 11 mm (range, 3-31 mm) and their final size was 12.5 mm (range, 3-42 mm). After a median follow-up time of 56 months (range, 12-163 months), the median cyst growth rate was 0.29 mm/year. Twelve patients developed worrisome features, no patients developed high-risk features, 4 patients had surgical resection, and no cancers developed. The rate of BD-IPMN growth was greater in patients who developed worrisome features than those who did not (2.84 mm/year vs 0.23 mm/year; P < .001). The odds of developing worrisome features increased for each unit (mm) increase in cyst size (odds ratio, 1.149; 95% CI, 1.035-1.276, P = .009). In a retrospective analysis of images from patients with BD-IPMN, we found low-risk BD-IPMNs to grow at an extremely low rate (less than 0.3 mm/year). BD-IPMNs in only about 6% of patients developed worrisome features, and none developed high-risk features

  18. Growth rates in modern speleothems from Santana Cave, Brazil, by the 210Pb-method

    International Nuclear Information System (INIS)

    Bonotto, D.M.; Karmann, I.; Baskaran, M.M.

    2012-01-01

    The Santana Cave is located at the Upper Ribeira Touristic State Park (PETAR-Parque Estadual Turístico do Alto Ribeira) in southern São Paulo State, Brazil. This paper describes 210 Pb activity concentration data in soda straw stalactites samples collected at Salão das Flores in Santana Cave that is a fossil tributary of the cave river. Non-expensive alpha counting following some analytical steps for extracting and depositing 210 Po were used for providing the 210 Pb data. In the analyzed samples, 210 Pb values of increasingly older samples fitted an exponential curve, thus suggesting that the production of 210 Pb has been constant with time. Also, the near-ideal fit indicated that the growth was uniform and there was no break in the continuous growth. The soda straw growth rates were determined from the best fit to the exponential curve through the 210 Pb activity concentration. The results of the measurements allowed estimate a longitudinal rate corresponding to 1.3 mm/yr and a lateral rate of 0.01 mm/yr, which permitted calculate times of 70 years and 317–498 years for their formation, respectively. The lateral growth rate is compatible with values from studies of chemical weathering rates held under laboratory and natural conditions.

  19. An inverse modeling procedure to determine particle growth and nucleation rates from measured aerosol size distributions

    Directory of Open Access Journals (Sweden)

    B. Verheggen

    2006-01-01

    Full Text Available Classical nucleation theory is unable to explain the ubiquity of nucleation events observed in the atmosphere. This shows a need for an empirical determination of the nucleation rate. Here we present a novel inverse modeling procedure to determine particle nucleation and growth rates based on consecutive measurements of the aerosol size distribution. The particle growth rate is determined by regression analysis of the measured change in the aerosol size distribution over time, taking into account the effects of processes such as coagulation, deposition and/or dilution. This allows the growth rate to be determined with a higher time-resolution than can be deduced from inspecting contour plots ('banana-plots''. Knowing the growth rate as a function of time enables the evaluation of the time of nucleation of measured particles of a certain size. The nucleation rate is then obtained by integrating the particle losses from time of measurement to time of nucleation. The regression analysis can also be used to determine or verify the optimum value of other parameters of interest, such as the wall loss or coagulation rate constants. As an example, the method is applied to smog chamber measurements. This program offers a powerful interpretive tool to study empirical aerosol population dynamics in general, and nucleation and growth in particular.

  20. IGF-1 and insulin as growth hormones.

    Science.gov (United States)

    Laron, Zvi

    2004-01-01

    IGF-1 generated in the liver is the anabolic effector and linear growth promoting hormone of the pituitary growth hormone (GH). This is evidenced by dwarfism in states of congenital IGF-1 deficiency, Igf1 gene mutation/deletions or knockouts, and in Laron syndrome (LS), due to GH receptor gene mutations/deletions or IGF-1 receptor blocking. In a positive way, daily IGF-1 administration to stunted patients with LS or hGH gene deletion accelerates linear growth velocity. IGF-1 acts on the proliferative cells of the epiphyseal cartilage. IGF-1 also induces organ and tissue growth; its absence causing organomicria. Insulin shares a common ancestry with IGF-1 and with 45% amino acid homology, as well as very close relationships in the structure of its receptors and post-receptor cascade, also acts as a growth hormone. It has protein anabolic activity and stimulates IGF-1 synthesis. Pancreas agenesis causes short babies, and obese children with hyperinsulinism, with or without pituitary GH, have an accelerated growth rate and skeletal maturation; so do babies with macrosomia. Whether the insulin growth effect is direct, or mediated by IGF-1 or leptin is controversial.

  1. Effect of repeated oral therapeutic doses of methylphenidate on food intake and growth rate in rats.

    Science.gov (United States)

    Alam, Nausheen; Najam, Rahila

    2015-01-01

    Central nervous system stimulants are known to produce anorexia. Previous data suggest that methylphenidate can have variable effects on caloric intake and growth rate. A dose-response study was performed to monitor caloric intake, liquid intake and growth rate in rats following repeated administration of human oral therapeutic doses 2 mg/kg/day, 5mg/kg/day and 8mg/kg/day of methylphenidate. We found that food intake and water intake, increased in all weeks and at all doses used in the study. Growth rate increased more at higher dose (8mg/kg/day) and at low dose (2mg/kg/day) of methylphenidate in 1(st) and 2(nd) week whereas more decreased by the above doses in 3(rd) week, suggesting that food stimulation leads to initial increase in growth rate but long term administration of methylphenidate attenuate growth rate that is not due to modulation of appetite but may be due to anxiety and increased activity produce by stimulants. A possible role of DA, 5HT receptors in modulation of appetite and anxiety is discussed.

  2. Growth rate variation of the stalked barnacle Pollicipes pollicipes (Crustacea: Cirripedia using calcein as a chemical marker

    Directory of Open Access Journals (Sweden)

    David Jacinto

    2015-03-01

    Full Text Available This study describes the use of calcein as a chemical tagging methodology to estimate growth rate variation of the stalked barnacle Pollicipes pollicipes, an ecologically important intertidal species and economic resource, in SW Portugal. Calcein tagging had a high success rate (94% in marking both juvenile and adult barnacles for a period of 2.5 months, providing a valuable method for obtaining reliable data in growth studies of P. pollicipes. Growth rate decreased with barnacle size and was highly variable amongst individuals, particularly in smaller barnacles. No effect of shore level on barnacle growth was detected. Growth rates were higher in smaller juvenile barnacles, peaking at a 1.1-mm monthly increment in rostro-carinal length (RC for individuals with RC=5 mm, and decreased with barnacle size (monthly growth rates of 0.5 mm for adult barnacles with RC~12.5 mm. Growth rates observed in adults with commercial interest (RC ≥ 18 mm was < 0.25 mm per month. The advantages of tagging P. pollicipes with calcein were the possibility of mass marking individual barnacles of different size cohorts within a short period (less than 1 day of manipulation; and reduced time of fieldwork, which is very important because this species inhabits very exposed rocky shores.

  3. Determining the nucleation rate from the dimer growth probability

    NARCIS (Netherlands)

    Ter Horst, J.H.; Kashchiev, D.

    2005-01-01

    A new method is proposed for the determination of the stationary one-component nucleation rate J with the help of data for the growth probability P2 of a dimer which is the smallest cluster of the nucleating phase. The method is based on an exact formula relating J and P2, and is readily applicable

  4. Growth rate enhancement of free-electron laser by two consecutive ...

    Indian Academy of Sciences (India)

    2014-06-03

    Jun 3, 2014 ... been the subject of many papers published by different groups all around the world. The radiation is generated by relativistic electron beam passing through a wiggler. ..... Shown in figure 2 are plots of growth rate, Im ¯k, vs.

  5. Maximum Likelihood based comparison of the specific growth rates for P. aeruginosa and four mutator strains

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Mandsberg, Lotte Frigaard

    2008-01-01

    with an exponentially decaying function of the time between observations is suggested. A model with a full covariance structure containing OD-dependent variance and an autocorrelation structure is compared to a model with variance only and with no variance or correlation implemented. It is shown that the model...... are used for parameter estimation. The data is log-transformed such that a linear model can be applied. The transformation changes the variance structure, and hence an OD-dependent variance is implemented in the model. The autocorrelation in the data is demonstrated, and a correlation model...... that best describes data is a model taking into account the full covariance structure. An inference study is made in order to determine whether the growth rate of the five bacteria strains is the same. After applying a likelihood-ratio test to models with a full covariance structure, it is concluded...

  6. Maternal body size and condition determine calf growth rates in southern right whales

    DEFF Research Database (Denmark)

    Christiansen, Fredrik; Vivier, Fabien; Charlton, Claire

    2018-01-01

    The cost of reproduction is a key parameter determining a species' life history strategy. Despite exhibiting some of the fastest offspring growth rates among mammals, the cost of reproduction in baleen whales is largely unknown since standard field metabolic techniques cannot be applied. We...... quantified the cost of reproduction for southern right whales Eubalaena australis over a 3 mo breeding season. We did this by determining the relationship between calf growth rate and maternal rate of loss in energy reserves, using repeated measurements of body volume obtained from unmanned aerial vehicle...... period, and highlights the importance of sufficient maternal energy reserves for reproduction in this capital breeding species....

  7. Population Growth Rate: Teaching Guide. Measures of Progress Poster Kit Number 2.

    Science.gov (United States)

    World Bank, Washington, DC.

    This teaching guide accompanies the Population Growth Rate poster kit which is designed to teach students about population growth differences between rich and poor nations and about what people in developing countries are doing to help improve their quality of life. The guide is designed for use with: (1) a poster map of the world providing social…

  8. Role of temperature on growth and metabolic rate in the tenebrionid beetles Alphitobius diaperinus and Tenebrio molitor.

    Science.gov (United States)

    Bjørge, Julie Dahl; Overgaard, Johannes; Malte, Hans; Gianotten, Natasja; Heckmann, Lars-Henrik

    2018-03-10

    Insects are increasingly used as a dietary source for food and feed and it is therefore important to understand how rearing conditions affect growth and development of these agricultural animals. Temperature is arguably the most important factor affecting metabolism and growth rate in insects. Here, we investigated how rearing temperature affected growth rate, growth efficiency and macronutrient composition in two species of edible beetle larvae: Alphitobius diaperinus and Tenebrio molitor. Growth rates of both species were quantified at temperatures ranging from 15.2 to 38.0 °C after which we measured protein and lipid content of the different treatment groups. Metabolic rate was measured in a similar temperature range by measuring the rate of O 2 consumption (V·O 2 ) and CO 2 production (V·CO 2 ) using repeated measures closed respirometry. Using these measurements, we calculated the growth efficiency of mealworms by relating the energy assimilation rate to the metabolic rate. Maximum daily growth rates were 18.3% and 16.6% at 31 °C, for A. diaperinus and T. molitor respectively, and we found that A. diaperinus was better at maintaining growth at high temperatures while T. molitor had superior growth at lower temperatures. Both species had highest efficiencies of energy assimilation in the temperature range of 23.3-31.0 °C, with values close to 2 J assimilated/J metabolised in A. diaperinus and around 4 J assimilated/J metabolised in T. molitor. Compared to "conventional" terrestrial livestock, both species of insects were characterised by high growth rates and very high energy conversion efficiency at most experimental temperatures. For A. diaperinus, lipid content was approximately 30% of dry mass and protein content approximately 50% of dry mass across most temperatures. Temperature had a greater influence on the body composition of T. molitor. At 31.0 °C the lipid and protein content was measured to 47.4% and 37.9%, respectively but lipid

  9. Comparison of human dermal fibroblasts (HDFs) growth rate in culture media supplemented with or without basic fibroblast growth factor (bFGF).

    Science.gov (United States)

    Abdian, Narges; Ghasemi-Dehkordi, Payam; Hashemzadeh-Chaleshtori, Morteza; Ganji-Arjenaki, Mahbobe; Doosti, Abbas; Amiri, Beheshteh

    2015-12-01

    Basic fibroblast growth factor (bFGF or FGF-2) is a member of the FGF family secreted by different kinds of cells like HDFs and it is an important nutritional factor for cell growth and differentiation. The HDFs release bFGF in culture media at very low. The present study aims to investigate the HDFs growth rate in culture media supplemented either with or without bFGF. In brief, HDFs were isolated from human foreskin sample and were cultured in vitro in media containing bFGF and lack of this factor. The cells growth rate was calculated by trypan blue. The karyotyping was performed using G-banding to investigate the chromosomal abnormality of HDFs in both groups. Total RNA of each groups were extracted and cDNA samples were synthesized then, real-time Q-PCR was used to measure the expression level of p27kip1 and cyclin D1 genes normalized to internal control gene (GAPDH). The karyotype analysis showed that HDFs cultured in media or without bFGF had normal karyotype (46 chromosomes, XY) and chromosomal abnormalities were not observed. The cell growth rates in both groups were normal with proliferated exponentially but the slope of growth curve in HDFs cultured in media containing bFGF was increased. Karyotyp test showed that bFGF does not affect on cytogenetic stability of cells. The survey of p27kip1 and cyclin D1 genes by real-time Q-PCR showed that the expression level of these genes were up-regulated when adding bFGF in culture media (p culture media with growth factor like bFGF could enhance the proliferation and differentiation capacity of cells and improve cells growth rate. Similarly, fibroblast growth factors did not induce any chromosomal abnormality in cells. Furthermore, in HDFs cultured in bFGF supplemented media, the p27kip1 and cyclin D1 genes were up-regulated and suggesting an important role for bFGF in cell-cycle regulation and progression and fibroblast division stimulation. It also suggests that the effects of bFGF on different cell types with

  10. Influence of Cell-Cell Interactions on the Population Growth Rate in a Tumor

    Science.gov (United States)

    Chen, Yong

    2017-12-01

    The understanding of the macroscopic phenomenological models of the population growth at a microscopic level is important to predict the population behaviors emerged from the interactions between the individuals. In this work, we consider the influence of the population growth rate R on the cell-cell interaction in a tumor system and show that, in most cases especially small proliferative probabilities, the regulative role of the interaction will be strengthened with the decline of the intrinsic proliferative probabilities. For the high replication rates of an individual and the cooperative interactions, the proliferative probability almost has no effect. We compute the dependences of R on the interactions between the cells under the approximation of the nearest neighbor in the rim of an avascular tumor. Our results are helpful to qualitatively understand the influence of the interactions between the individuals on the growth rate in population systems. Supported by the National Natural Science Foundation of China under Grant Nos. 11675008 and 21434001

  11. Parameter estimations in predictive microbiology: Statistically sound modelling of the microbial growth rate.

    Science.gov (United States)

    Akkermans, Simen; Logist, Filip; Van Impe, Jan F

    2018-04-01

    When building models to describe the effect of environmental conditions on the microbial growth rate, parameter estimations can be performed either with a one-step method, i.e., directly on the cell density measurements, or in a two-step method, i.e., via the estimated growth rates. The two-step method is often preferred due to its simplicity. The current research demonstrates that the two-step method is, however, only valid if the correct data transformation is applied and a strict experimental protocol is followed for all experiments. Based on a simulation study and a mathematical derivation, it was demonstrated that the logarithm of the growth rate should be used as a variance stabilizing transformation. Moreover, the one-step method leads to a more accurate estimation of the model parameters and a better approximation of the confidence intervals on the estimated parameters. Therefore, the one-step method is preferred and the two-step method should be avoided. Copyright © 2017. Published by Elsevier Ltd.

  12. Climate is a stronger driver of tree and forest growth rates than soil and disturbance

    NARCIS (Netherlands)

    Toledo, M.; Poorter, L.; Peña-Claros, M.; Alarcón, A.; Balcázar, J.; Leaño, C.; Licona, J.C.; Llanque, O.; Vroomans, V.; Zuidema, P.; Bongers, F.

    2011-01-01

    1. Essential resources such as water, nutrients and light vary over space and time and plant growth rates are expected to vary accordingly. We examined the effects of climate, soil and logging disturbances on diameter growth rates at the tree and stand level, using 165 1-ha permanent sample plots

  13. Effects of Phlomis umbrosa Root on Longitudinal Bone Growth Rate in Adolescent Female Rats

    Directory of Open Access Journals (Sweden)

    Donghun Lee

    2016-04-01

    Full Text Available This study aimed to investigate the effects of Phlomis umbrosa root on bone growth and growth mediators in rats. Female adolescent rats were administered P. umbrosa extract, recombinant human growth hormone or vehicle for 10 days. Tetracycline was injected intraperitoneally to produce a glowing fluorescence band on the newly formed bone on day 8, and 5-bromo-2′-deoxyuridine was injected to label proliferating chondrocytes on days 8–10. To assess possible endocrine or autocrine/paracrine mechanisms, we evaluated insulin-like growth factor-1 (IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3 or bone morphogenetic protein-2 (BMP-2 in response to P. umbrosa administration in either growth plate or serum. Oral administration of P. umbrosa significantly increased longitudinal bone growth rate, height of hypertrophic zone and chondrocyte proliferation of the proximal tibial growth plate. P. umbrosa also increased serum IGFBP-3 levels and upregulated the expressions of IGF-1 and BMP-2 in growth plate. In conclusion, P. umbrosa increases longitudinal bone growth rate by stimulating proliferation and hypertrophy of chondrocyte with the increment of circulating IGFBP-3. Regarding the immunohistochemical study, the effect of P. umbrosa may also be attributable to upregulation of local IGF-1 and BMP-2 expressions in the growth plate, which can be considered as a GH dependent autocrine/paracrine pathway.

  14. New developments on size-dependent growth applied to the crystallization of sucrose

    Science.gov (United States)

    Martins, P. M.; Rocha, F.

    2007-12-01

    The effect of crystal size on the growth rate of sucrose (C 12H 22O 11) at 40 °C is investigated from a theoretical and an experimental point of view. Based on new perspectives resulting from the recently introduced spiral nucleation model [P.M. Martins, F. Rocha, Surf. Sci. 601 (2007) 3400], crystal growth rates are expressed in terms of mass deposition per time and crystal volume units. This alternative definition is demonstrated to be size-independent over the considered supersaturation range. The conventional overall growth rate expressed per surface area units is found to be linearly dependent on crystal size. The advantages of the "volumetric" growth rate concept are discussed. Sucrose dissolution rates were measured under reciprocal conditions of the growth experiments in order to investigate the two-way effect of crystal size on mass transfer rates and on the integration kinetics. Both effects are adequately described by combining a well-established diffusion-integration model and the spiral nucleation mechanism.

  15. Estimating blue whale skin isotopic incorporation rates and baleen growth rates: Implications for assessing diet and movement patterns in mysticetes

    Science.gov (United States)

    Busquets-Vass, Geraldine; Newsome, Seth D.; Calambokidis, John; Serra-Valente, Gabriela; Jacobsen, Jeff K.; Aguíñiga-García, Sergio; Gendron, Diane

    2017-01-01

    Stable isotope analysis in mysticete skin and baleen plates has been repeatedly used to assess diet and movement patterns. Accurate interpretation of isotope data depends on understanding isotopic incorporation rates for metabolically active tissues and growth rates for metabolically inert tissues. The aim of this research was to estimate isotopic incorporation rates in blue whale skin and baleen growth rates by using natural gradients in baseline isotope values between oceanic regions. Nitrogen (δ15N) and carbon (δ13C) isotope values of blue whale skin and potential prey were analyzed from three foraging zones (Gulf of California, California Current System, and Costa Rica Dome) in the northeast Pacific from 1996–2015. We also measured δ15N and δ13C values along the lengths of baleen plates collected from six blue whales stranded in the 1980s and 2000s. Skin was separated into three strata: basale, externum, and sloughed skin. A mean (±SD) skin isotopic incorporation rate of 163±91 days was estimated by fitting a generalized additive model of the seasonal trend in δ15N values of skin strata collected in the Gulf of California and the California Current System. A mean (±SD) baleen growth rate of 15.5±2.2 cm y-1 was estimated by using seasonal oscillations in δ15N values from three whales. These oscillations also showed that individual whales have a high fidelity to distinct foraging zones in the northeast Pacific across years. The absence of oscillations in δ15N values of baleen sub-samples from three male whales suggests these individuals remained within a specific zone for several years prior to death. δ13C values of both whale tissues (skin and baleen) and potential prey were not distinct among foraging zones. Our results highlight the importance of considering tissue isotopic incorporation and growth rates when studying migratory mysticetes and provide new insights into the individual movement strategies of blue whales. PMID:28562625

  16. Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Steve A. [Univ. of Southern California, Los Angeles, CA (United States)

    2017-10-20

    Objectives: Several breakthroughs have been recently made in our understanding of plant growth and biomass accumulation. It was found that plant growth is rhythmically controlled throughout the day by the circadian clock through a complex interplay of light and phytohormone signaling pathways. While plants such as the C4 energy crop sorghum (Sorghum bicolor (L.) Moench) and possibly the C3 grass Brachypodium distachyon also exhibit daily rhythms in growth rate, the molecular details of its regulation remain to be explored. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to future strategies to optimize energy crop biomass yield. Here we propose to devise a systems approach to identify, in parallel, regulatory hubs associated with rhythmic growth in C3 and C4 plants. We propose to use rhythmicity in daily growth patterns to drive the discovery of regulatory network modules controlling biomass accumulation. Description: The project is divided in three main parts: 1) Performing time-lapse imaging and growth measurement in B. distachyon and S. bicolor to determine growth rate dynamic during the day/night cycle. Identifying growth-associated genes whose expression patterns follow the observed growth dynamics using deep sequencing technology, 2) identifying regulators of these genes by screening for DNA-binding proteins interacting with the growth-associated gene promoters identified in Aim 1. Screens will be performed using a validated yeast-one hybrid strategy paired with a specifically designed B. distachyon and S. bicolor transcription factor libraries (1000 clones each), and 3) Selecting 50 potential growth regulators from the screen for downstream characterization. The selection will be made by using a sytems biology approach by calculating the connectivity between growth rate, rhythmic gene expression profiles and TF expression profile and determine which TF is likely part of a hub

  17. Value of volume measurements in evaluating abdominal aortic aneurysms growth rate and need for surgical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kontopodis, Nikolaos, E-mail: kontopodisn@yahoo.gr [Department of Vascular Surgery, University of Crete Medical School, Heraklion (Greece); Metaxa, Eleni, E-mail: emmetaxa@gmail.com [Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Crete (Greece); Papaharilaou, Yannis, E-mail: yannisp@iacm.forth.gr [Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Crete (Greece); Georgakarakos, Efstratios, E-mail: efstratiosgeorg@gmail.com [Vascular Surgery Department, “Demokritus” University of Thrace Medical School, Alexandroupolis (Greece); Tsetis, Dimitris, E-mail: tsetis@med.uoc.gr [Interventional Radiology Unit, Department of Radiology, University of Crete Medical School, Heraklion, Crete (Greece); Ioannou, Christos V., E-mail: ioannou@med.uoc.gr [Department of Vascular Surgery, University of Crete Medical School, Heraklion (Greece)

    2014-07-15

    Purpose: To examine whether indices other than the traditionally used abdominal aortic aneurysm (AAA) maximum diameter, such as AAA volume, intraluminal thrombus (ILT) thickness and ILT volume, may be superior to evaluate aneurismal enlargement. Materials and methods: Thirty-four small AAAs (initially presenting a maximum diameter <5.5 cm which is the threshold for surgical repair) with an initial and a follow-up CT were examined. Median increase and percentile annual change of these variables was calculated. Correlation between growth rates as determined by the new indices under evaluation and those of maximum diameter were assessed. AAAs were divided according to outcome (surveillance vs. elective repair after follow-up which is based on the maximum diameter criterion) and according to growth rate (high vs. low) based on four indices. Contingency between groups of high/low growth rate regarding each of the four indices on one hand and those regarding need for surgical repair on the other was assessed. Results: A strong correlation between growth rates of maximum diameter and those of AAA and ILT volumes could be established. Evaluation of contingency between groups of outcome and those of growth rate revealed significant associations only for AAA and ILT volumes. Subsequently AAAs with a rapid volumetric increase over time had a likelihood ratio of 10 to be operated compared to those with a slower enlargement. Regarding increase of maximum diameter, likelihood ratio between AAAs with rapid and those with slow expansion was only 3. Conclusion: Growth rate of aneurysms regarding 3Dimensional indices of AAA and ILT volumes is significantly associated with the need for surgical intervention while the same does not hold for growth rates determined by 2Dimensional indices of maximum diameter and ILT thickness.

  18. Value of volume measurements in evaluating abdominal aortic aneurysms growth rate and need for surgical treatment

    International Nuclear Information System (INIS)

    Kontopodis, Nikolaos; Metaxa, Eleni; Papaharilaou, Yannis; Georgakarakos, Efstratios; Tsetis, Dimitris; Ioannou, Christos V.

    2014-01-01

    Purpose: To examine whether indices other than the traditionally used abdominal aortic aneurysm (AAA) maximum diameter, such as AAA volume, intraluminal thrombus (ILT) thickness and ILT volume, may be superior to evaluate aneurismal enlargement. Materials and methods: Thirty-four small AAAs (initially presenting a maximum diameter <5.5 cm which is the threshold for surgical repair) with an initial and a follow-up CT were examined. Median increase and percentile annual change of these variables was calculated. Correlation between growth rates as determined by the new indices under evaluation and those of maximum diameter were assessed. AAAs were divided according to outcome (surveillance vs. elective repair after follow-up which is based on the maximum diameter criterion) and according to growth rate (high vs. low) based on four indices. Contingency between groups of high/low growth rate regarding each of the four indices on one hand and those regarding need for surgical repair on the other was assessed. Results: A strong correlation between growth rates of maximum diameter and those of AAA and ILT volumes could be established. Evaluation of contingency between groups of outcome and those of growth rate revealed significant associations only for AAA and ILT volumes. Subsequently AAAs with a rapid volumetric increase over time had a likelihood ratio of 10 to be operated compared to those with a slower enlargement. Regarding increase of maximum diameter, likelihood ratio between AAAs with rapid and those with slow expansion was only 3. Conclusion: Growth rate of aneurysms regarding 3Dimensional indices of AAA and ILT volumes is significantly associated with the need for surgical intervention while the same does not hold for growth rates determined by 2Dimensional indices of maximum diameter and ILT thickness

  19. The Effect of CO2 Injection on Macroalgae Gelidium latifolium Biomass Growth Rate and Carbohydrate Content

    Directory of Open Access Journals (Sweden)

    Mujizat Kawaroe

    2016-06-01

    Full Text Available There are many species of macroalga grow in marine ecosystem and potentially as raw material for bioethanol resource. Bioethanol is a conversion result of carbohydrate, one of macroalgae biomass content. The exploration of macroalgae require information about  growth rate ability to determine availability in the nature. This research analyze growth rate and carbohydrate content of marine macroalga Gelidium latifolium on cultivation using varied injection of carbon dioxide and aeration. The treatments were control (K, 2000 cc CO2 injection and aeration (P1, 3000 cc CO2 injection and aeration (P2, 2000 cc CO2 injection without aeration (P3, and 3000 cc CO2 injection without aeration (P4. Samples weight were 3 gram in early cultivation on laboratorium scale for 42 days observation. The results showed that the daily growth rate Gelidium latifolium during the study ranged from 0.02-1.06%. The highest daily growth rate was 1.06±0.14% (P2. Carbohydrate yield was 18.23% in early cultivation then 19.40% (K and P2, 20.40% (P1, 16.87% (K3, and 16.40% (P4 after cultivation. The high of carbohydrates value may not guarantee the sustainable Gelidium latifolium biomass utilization as raw material for bioethanol production because of the low growth rate, thus it is necessary to modified and encourage cultivation method effectively. Keywords: CO2 injection, growth rate, carbohydrate, macroalgae, Gelidium latifolium

  20. Interstate Differences on Economic Growth Rates in Australia, 1953-54 to 1990-91

    OpenAIRE

    Harris, P; Harris, D

    1992-01-01

    This paper examines interstate differences in economic growth rates in Australia over the period 1953-54 to 1990-91 using a six State classification (with ACT included in New South Wales and the Northern Territory in South Australia). The economic growth rate is measured by the increase in constant price gross state product at factor cost (GSP) per head of population over time, using three year moving averages of GSP and population to remove some of the annual fluctuations in the data. The an...

  1. In situ growth rates and biofilm development of Pseudomonas aeruginosa populations in chronic lung infections

    DEFF Research Database (Denmark)

    Yang, L.; Haagensen, J.A.; Jelsbak, L.

    2008-01-01

    matrix, whereas nonmucoid variants were present mainly as dispersed cells. To obtain estimates of the growth rates of P. aeruginosa in CF lungs, we used quantitative FISH to indirectly measure growth rates of bacteria in sputum samples (reflecting the in vivo lung conditions). The concentration of r......The growth dynamics of bacterial pathogens within infected hosts are a fundamental but poorly understood feature of most infections. We have focused on the in situ distribution and growth characteristics of two prevailing and transmissible Pseudomonas aeruginosa clones that have caused chronic lung......RNA in bacteria isolated from sputa was measured and correlated with the rRNA contents of the same bacteria growing in vitro at defined rates. The results showed that most cells were actively growing with doubling times of between 100 and 200 min, with some growing even faster. Only a small stationary...

  2. Preterm infant linear growth and adiposity gain: trade-offs for later weight status and intelligence quotient.

    Science.gov (United States)

    Belfort, Mandy B; Gillman, Matthew W; Buka, Stephen L; Casey, Patrick H; McCormick, Marie C

    2013-12-01

    To examine trade-offs between cognitive outcome and overweight/obesity in preterm-born infants at school age and young adulthood in relation to weight gain and linear growth during infancy. We studied 945 participants in the Infant Health and Development Program, an 8-center study of preterm (≤37 weeks gestational age), low birth weight (≤2500 g) infants from birth to age 18 years. Adjusting for maternal and child factors in logistic regression, we estimated the odds of overweight/obesity (body mass index [BMI] ≥85th percentile at age 8 or ≥25 kg/m(2) at age 18) and in separate models, low IQ (growth from term to 4 months was associated with lower odds of IQ growth soon after term was associated with better cognition, but also with a greater risk of overweight/obesity at age 8 years and 18 years. BMI gain over the entire 18 months after term was associated with later risk of overweight/obesity, with less evidence of a benefit for IQ. Copyright © 2013 Mosby, Inc. All rights reserved.

  3. Flexibility in metabolic rate confers a growth advantage under changing food availability.

    Science.gov (United States)

    Auer, Sonya K; Salin, Karine; Rudolf, Agata M; Anderson, Graeme J; Metcalfe, Neil B

    2015-09-01

    1. Phenotypic flexibility in physiological, morphological and behavioural traits can allow organisms to cope with environmental challenges. Given recent climate change and the degree of habitat modification currently experienced by many organisms, it is therefore critical to quantify the degree of phenotypic variation present within populations, individual capacities to change and what their consequences are for fitness. 2. Flexibility in standard metabolic rate (SMR) may be particularly important since SMR reflects the minimal energetic cost of living and is one of the primary traits underlying organismal performance. SMR can increase or decrease in response to food availability, but the consequences of these changes for growth rates and other fitness components are not well known. 3. We examined individual variation in metabolic flexibility in response to changing food levels and its consequences for somatic growth in juvenile brown trout (Salmo trutta). 4. SMR increased when individuals were switched to a high food ration and decreased when they were switched to a low food regime. These shifts in SMR, in turn, were linked with individual differences in somatic growth; those individuals that increased their SMR more in response to elevated food levels grew fastest, while growth at the low food level was fastest in those individuals that depressed their SMR most. 5. Flexibility in energy metabolism is therefore a key mechanism to maximize growth rates under the challenges imposed by variability in food availability and is likely to be an important determinant of species' resilience in the face of global change. © 2015 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  4. Effect of Alfvén waves on the growth rate of the electron-cyclotron maser emission

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D. J., E-mail: djwu@pmo.ac.cn [Purple Mountain Observatory, CAS, Nanjing 210008 (China)

    2014-06-15

    By using the non-relativistic approximation for the calculation of growth rates, but taking account of the weakly relativistic modification for the electron-cyclotron resonance condition, it is shown that the effect of Alfvén waves (AWs) on the electron-cyclotron maser emission leads to the significant increase of the O-mode growth rate, but has little effect on the X-mode growth rate. We propose that this is because the O-mode wave has the field-aligned polarization sense in the same as the field-aligned oscillatory current, which is created by the field-aligned oscillatory motion of the energetic electrons caused via the presence of AWs. It is this field-aligned oscillatory current that contributes a novel growth rate to the O-mode wave but has little effect on the X-mode wave.

  5. Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

    Directory of Open Access Journals (Sweden)

    Peder Eliasson

    2008-05-01

    Full Text Available The Compact Linear Collider (CLIC main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs, indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Finally, it is shown how the method can be used to design a feedback system that is optimized for the optics of the machine and the ground motion spectrum of the particular site. This feedback system gives an emittance growth rate that is approximately 10 times lower than that of traditional trajectory feedbacks. The robustness of the optimized feedback system is studied for a number of additional imperfections, e.g., dipole corrector imperfections and faulty knowledge about the machine optics, with promising results.

  6. Dynamic imperfections and optimized feedback design in the Compact Linear Collider main linac

    Science.gov (United States)

    Eliasson, Peder

    2008-05-01

    The Compact Linear Collider (CLIC) main linac is sensitive to dynamic imperfections such as element jitter, injected beam jitter, and ground motion. These effects cause emittance growth that, in case of ground motion, has to be counteracted by a trajectory feedback system. The feedback system itself will, due to jitter effects and imperfect beam position monitors (BPMs), indirectly cause emittance growth. Fast and accurate simulations of both the direct and indirect effects are desirable, but due to the many elements of the CLIC main linac, simulations may become very time consuming. In this paper, an efficient way of simulating linear (or nearly linear) dynamic effects is described. The method is also shown to facilitate the analytic determination of emittance growth caused by the different dynamic imperfections while using a trajectory feedback system. Emittance growth expressions are derived for quadrupole, accelerating structure, and beam jitter, for ground motion, and for noise in the feedback BPMs. Finally, it is shown how the method can be used to design a feedback system that is optimized for the optics of the machine and the ground motion spectrum of the particular site. This feedback system gives an emittance growth rate that is approximately 10 times lower than that of traditional trajectory feedbacks. The robustness of the optimized feedback system is studied for a number of additional imperfections, e.g., dipole corrector imperfections and faulty knowledge about the machine optics, with promising results.

  7. How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox

    DEFF Research Database (Denmark)

    Snoep, Jacky L.; Jensen, Peter Ruhdal; Groeneveld, Philip

    1994-01-01

    how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. this analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth...

  8. Linear theory of a cold relativistic beam in a strongly magnetized finite-geometry plasma

    International Nuclear Information System (INIS)

    Gagne, R.R.J.; Shoucri, M.M.

    1976-01-01

    The linear theory of a finite-geometry cold relativistic beam propagating in a cold homogeneous finite-geometry plasma, is investigated in the case of a strongly magnetized plasma. The beam is assumed to propagate parallel to the external magnetic field. It is shown that the instability which takes place at the Cherenkov resonance ωapprox. =k/subz/v/subb/ is of the convective type. The effect of the finite geometry on the instability growth rate is studied and is shown to decrease the growth rate, with respect to the infinite geometry, by a factor depending on the ratio of the beam-to-plasma radius

  9. TEST OF THE CATCH-UP HYPOTHESIS IN AFRICAN AGRICULTURAL GROWTH RATES

    Directory of Open Access Journals (Sweden)

    Kalu Ukpai IFEGWU

    2015-11-01

    Full Text Available The paper tested the catch-up hypothesis in agricultural growth rates of twenty-six African countries. Panel data used was drawn from the Food and Agricultural Organization Statistics (FAOSTAT of the United Nations. The Data Envelopment Analysis Method for measuring productivity was used to estimate productivity growth rates. The cross-section framework consisting of sigma-convergence and beta-convergence was employed to test the catching up process. Catching up is said to exist if the value of beta is negative and significant. Since catching up does not necessarily imply narrowing of national productivity inequalities, sigma-convergence which measures inequality, was estimated for the same variables. The results showed evidence of the catch-up process, but failed to find a narrowing of productivity inequalities among countries.

  10. Neonatal Diagnostics: Towards Dynamic Growth Charts of Neuro-motor control

    Directory of Open Access Journals (Sweden)

    Elizabeth B Torres

    2016-11-01

    Full Text Available Current rise of neurodevelopmental disorders, poses a critical need to detect risk early in order to rapidly intervene. One of the tools Pediatricians use to track development is the standard Growth Chart. The Growth Charts are somewhat limited in predicting possible neurodevelopmental issues. They rely on linear models and assumptions of normality for physical growth data —obscuring key statistical information about possible neurodevelopmental risk in growth data that actually has accelerated, non-linear rates-of-change and variability encompassing skewed distributions. Here we use new analytics to profile growth data from 36 newborn babies that were tracked longitudinally for 5 months. By switching to incremental (velocity-based growth charts and combining these dynamic changes with underlying fluctuations in motor performance—as they transition from spontaneous random noise to a systematic signal— we demonstrate a method to detect very early stunting in the development of voluntary neuro-motor control and to flag risk of neurodevelopmental derail.

  11. Effect of feeding frequency and feeding rate on growth performance ...

    African Journals Online (AJOL)

    Fish fed at higher feeding rates accumulated significantly more lipid within the body and had associated decreases in moisture, protein, and ash content, but carcass composition was unaffected by feeding frequency. Juvenile pompano show better growth performance when fed 10% BW/day 3 and 6 times a day.

  12. A comparison of growth rate of late Holocene stalagmites with atmospheric precipitation and temperature, and its implications for paleoclimatology

    Science.gov (United States)

    Railsback, L. Bruce

    2018-05-01

    Growth rate of stalagmites can vary with many factors of physical environment, ecology, and karst hydrogeology, to the extent that growth rates calculated from a carefully selected set of data from 80 stalagmites from around the world vary by a factor of 400 from smallest to largest. Growth rates of those 80 stalagmites nonetheless collectively show correlations to atmospheric precipitation and temperature that are non-trivial (r2 = 0.12 and 0.20, respectively) and unlikely to have arisen randomly (p = 0.002 and 0.00002). Those global relationships are also supported by previously published studies of individual drip sites. The general trend of growth rates is not a monotonic increase with precipitation; instead, it reaches a maximum at annual precipitation rates between 700 and 2300 mm/year, which both counters many model predictions that growth rates should increase monotonically with drip rate and complicates use of growth rate as a proxy for past precipitation. The general trend of growth rates among the 80 stalagmites is a monotonic increase with temperature. However, the low values of r2 in both of these general trends indicate that growth rate can be at best a qualitative rather than quantitative proxy of past conditions. Growth rate shows no statistically significant relationship to effective precipitation, seemingly because of the confounding effect of temperature. Growth rates of aragonite-bearing stalagmites are commonly greater than rates in stalagmites in which calcite is the only carbonate mineral, suggesting both the need for careful identification of mineralogy and the special applicability of aragonitic stalagmites in high-resolution studies. Aragonite has exceptionally great frequency in settings with low effective atmospheric precipitation, supporting previous linkages of that mineral to warm dry environments. Closely-spaced sampling used in recent paleoclimatological studies suggests that unexploited long-term low-resolution records of past

  13. Neutron equivalent dose rates at the surroundings of the electron linear accelerator operated by the university of Sao Paulo - Physics institute

    International Nuclear Information System (INIS)

    Yanagihara, L.S.

    1984-01-01

    For the determination of the neutron dose rates at the surroundings of an electron linear accelerators it is necessary the knowledge of the neutron spectrum or its mean energy, because the conversion factor of the flux in equivalent dose rates, is strongly dependent on the neutron energy. Taking this fact into consideration, equivalent dose rates were determined in the three representative sites of the IF/USP Linear Electron Accelerator. Also, due to the radiation field be pulsed, a theoretical and experimental study has been realized to evaluate the effect produced by the variation of the field on the detector. (author)

  14. Institutions and growth: theoretical foundations and empirical evidence

    International Nuclear Information System (INIS)

    Wagner, A.F.

    2000-09-01

    Institutions and growth rates are strongly linked both theoretically and empirically. They act through 'efficiency of governance'), as institutions of conflict management, and as devices for inter temporal optimization. Contrary to most of the literature, a non-linear (inversely u-shaped) influence of institutions on growth is also formally derived as a general hypothesis; this reflects the widely neglected notion that institutions also bring opportunity costs with them. Systematic econometric evaluations for a world-wide cross-sectional sample and a European Union panel show mixed results: the rule of law, property rights, and contract and law enforcement are consistently positively related to growth. In Europe, a non-linear relationship is often found for these and other institutions. Corporatism and trust are good for growth in Europe; both bring with them significant rent-seeking costs, though. Comparing the results one notes that no easy transfer of knowledge is possible from one sample to the other. This is an important policy conclusion in its own right. (author)

  15. Quorum sensing influences Vibrio harveyi growth rates in a manner not fully accounted for by the marker effect of bioluminescence.

    Science.gov (United States)

    Nackerdien, Zeena E; Keynan, Alexander; Bassler, Bonnie L; Lederberg, Joshua; Thaler, David S

    2008-02-27

    The light-emitting Vibrios provide excellent material for studying the interaction of cellular communication with growth rate because bioluminescence is a convenient marker for quorum sensing. However, the use of bioluminescence as a marker is complicated because bioluminescence itself may affect growth rate, e.g. by diverting energy. The marker effect was explored via growth rate studies in isogenic Vibrio harveyi (Vh) strains altered in quorum sensing on the one hand, and bioluminescence on the other. By hypothesis, growth rate is energy limited: mutants deficient in quorum sensing grow faster because wild type quorum sensing unleashes bioluminescence and bioluminescence diverts energy. Findings reported here confirm a role for bioluminescence in limiting Vh growth rate, at least under the conditions tested. However, the results argue that the bioluminescence is insufficient to explain the relationship of growth rate and quorum sensing in Vh. A Vh mutant null for all genes encoding the bioluminescence pathway grew faster than wild type but not as fast as null mutants in quorum sensing. Vh quorum sensing mutants showed altered growth rates that do not always rank with their relative increase or decrease in bioluminescence. In addition, the cell-free culture fluids of a rapidly growing Vibrio parahaemolyticus (Vp) strain increased the growth rate of wild type Vh without significantly altering Vh's bioluminescence. The same cell-free culture fluid increased the bioluminescence of Vh quorum mutants. The effect of quorum sensing on Vh growth rate can be either positive or negative and includes both bioluminescence-dependent and independent components. Bioluminescence tends to slow growth rate but not enough to account for the effects of quorum sensing on growth rate.

  16. Quorum sensing influences Vibrio harveyi growth rates in a manner not fully accounted for by the marker effect of bioluminescence.

    Directory of Open Access Journals (Sweden)

    Zeena E Nackerdien

    2008-02-01

    Full Text Available The light-emitting Vibrios provide excellent material for studying the interaction of cellular communication with growth rate because bioluminescence is a convenient marker for quorum sensing. However, the use of bioluminescence as a marker is complicated because bioluminescence itself may affect growth rate, e.g. by diverting energy.The marker effect was explored via growth rate studies in isogenic Vibrio harveyi (Vh strains altered in quorum sensing on the one hand, and bioluminescence on the other. By hypothesis, growth rate is energy limited: mutants deficient in quorum sensing grow faster because wild type quorum sensing unleashes bioluminescence and bioluminescence diverts energy. Findings reported here confirm a role for bioluminescence in limiting Vh growth rate, at least under the conditions tested. However, the results argue that the bioluminescence is insufficient to explain the relationship of growth rate and quorum sensing in Vh. A Vh mutant null for all genes encoding the bioluminescence pathway grew faster than wild type but not as fast as null mutants in quorum sensing. Vh quorum sensing mutants showed altered growth rates that do not always rank with their relative increase or decrease in bioluminescence. In addition, the cell-free culture fluids of a rapidly growing Vibrio parahaemolyticus (Vp strain increased the growth rate of wild type Vh without significantly altering Vh's bioluminescence. The same cell-free culture fluid increased the bioluminescence of Vh quorum mutants.The effect of quorum sensing on Vh growth rate can be either positive or negative and includes both bioluminescence-dependent and independent components. Bioluminescence tends to slow growth rate but not enough to account for the effects of quorum sensing on growth rate.

  17. Interest Rate Deregulation, Bank Development And Economic Growth In South Africa: An Empirical Investigation

    OpenAIRE

    Nicholas M Odhiambo

    2010-01-01

    In this paper the dynamic relationship between interest rate reforms, bank-based financial development and economic growth is examined – using two models in a stepwise fashion. In the first model, the impact of interest rate reforms on financial development is examined using a financial deepening model. In the second model, the dynamic causal relationship between financial development and economic growth is examined, by including investment as an intermittent variable in the bi-variate settin...

  18. Earthquake Cycle Simulations with Rate-and-State Friction and Linear and Nonlinear Viscoelasticity

    Science.gov (United States)

    Allison, K. L.; Dunham, E. M.

    2016-12-01

    We have implemented a parallel code that simultaneously models both rate-and-state friction on a strike-slip fault and off-fault viscoelastic deformation throughout the earthquake cycle in 2D. Because we allow fault slip to evolve with a rate-and-state friction law and do not impose the depth of the brittle-to-ductile transition, we are able to address: the physical processes limiting the depth of large ruptures (with hazard implications); the degree of strain localization with depth; the relative partitioning of fault slip and viscous deformation in the brittle-to-ductile transition zone; and the relative contributions of afterslip and viscous flow to postseismic surface deformation. The method uses a discretization that accommodates variable off-fault material properties, depth-dependent frictional properties, and linear and nonlinear viscoelastic rheologies. All phases of the earthquake cycle are modeled, allowing the model to spontaneously generate earthquakes, and to capture afterslip and postseismic viscous flow. We compare the effects of a linear Maxwell rheology, often used in geodetic models, with those of a nonlinear power law rheology, which laboratory data indicates more accurately represents the lower crust and upper mantle. The viscosity of the Maxwell rheology is set by power law rheological parameters with an assumed a geotherm and strain rate, producing a viscosity that exponentially decays with depth and is constant in time. In contrast, the power law rheology will evolve an effective viscosity that is a function of the temperature profile and the stress state, and therefore varies both spatially and temporally. We will also integrate the energy equation for the thermomechanical problem, capturing frictional heat generation on the fault and off-fault viscous shear heating, and allowing these in turn to alter the effective viscosity.

  19. Growth rate of matter perturbations as a probe of large-scale magnetism

    CERN Document Server

    Giovannini, Massimo

    2011-01-01

    The growth rate of matter perturbations is computed in a magnetized environment for the LambdaCDM and wCDM paradigms. It is argued that the baryons do not necessarily follow into the dark matter potential wells after they are released from the drag of the photons. The baryonic evolution equations inherit a forcing term whose explicit form depends on the plasma description and can be deduced, for instance, in the resistive magnetohydrodynamical approximation. After deriving an analytical expression for the growth rate applicable when dark energy does not cluster, the effects of relativistic corrections and of the inhomogeneities associated with the other species of the plasma are taken into account numerically. The spectral amplitudes and slopes of the stochastic magnetic background are selected to avoid appreciable distortions in the measured temperature and polarization anisotropies of the Cosmic Microwave Background. The growth of structures in the current paradigms of structure formation represents a compl...

  20. The impact of risk management on internal and sustainable growth rate: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Hamid Reza Vakili Fard

    2014-09-01

    Full Text Available Measuring the relative risk of firms has been an open discussion among researchers. There are many studies on learning how leverage may influence on growth of the firms. This article reviews the relationship between risk management, internal and sustainable growth of accepted companies in Tehran stock exchange. The survey considers three types of risks including operating, financial and compound and investigates their relationships with internal growth rate as well as sustainable growth rate. Using some regression techniques, the study has determined negative and meaningful relationships between different types of leverage on side and internal as well as sustainable growth on the other side.

  1. Linear and non-linear amplification of high-mode perturbations at the ablation front in HiPER targets

    Energy Technology Data Exchange (ETDEWEB)

    Olazabal-Loume, M; Breil, J; Hallo, L; Ribeyre, X [CELIA, UMR 5107 Universite Bordeaux 1-CNRS-CEA, 351 cours de la Liberation, 33405 Talence (France); Sanz, J, E-mail: olazabal@celia.u-bordeaux1.f [ETSI Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)

    2011-01-15

    The linear and non-linear sensitivity of the 180 kJ baseline HiPER target to high-mode perturbations, i.e. surface roughness, is addressed using two-dimensional simulations and a complementary analysis by linear and non-linear ablative Rayleigh-Taylor models. Simulations provide an assessment of an early non-linear stage leading to a significant deformation of the ablation surface for modes of maximum linear growth factor. A design using a picket prepulse evidences an improvement in the target stability inducing a delay of the non-linear behavior. Perturbation evolution and shape, evidenced by simulations of the non-linear stage, are analyzed with existing self-consistent non-linear theory.

  2. Child feeding style is associated with food intake and linear growth in rural Ethiopia.

    Science.gov (United States)

    Abebe, Zeweter; Haki, Gulelat Desse; Baye, Kaleab

    2017-09-01

    Little is known about mother-child feeding interactions and how this is associated with food intake and linear growth. To characterize mother-child feeding styles and investigate their associations with accepted mouthful and linear growth in west Gojam, rural Ethiopia. Two, in-home, meal observations of children aged 12-23 months (n = 100) were video-taped. The number of mouthful accepted was counted and the caregiver/child feeding styles were coded into positive/negative categories of self-feeding, responsive-feeding, active-feeding, social-behavior and distraction. Data on socio-demographic characteristics, child feeding practices, perception about child's overall appetite, and strategies adopted to overcome food refusal were collected through questionnaire-based interviews. Child and mothers' anthropometric measurements were also taken. Stunting was highly prevalent (48%) and the number of mouthful accepted was very low. Offering breastmilk and threatening to harm were the main strategies adopted to overcome food refusal. Although all forms of feeding style were present, active positive feeding style was dominant (90%) and was positively associated with mouthful accepted. Talking with non-feeding partner (64%), and domestic animals (24%) surrounding the feeding place were common distractions of feeding. Feeding was mostly terminated by caregivers (75%), often prematurely. Overall, caregivers of stunted children had poorer complementary- and breast-feeding practices and were less responsive to child's hunger and satiation cues (P responsive feeding behaviors were associated with child's number of mouthful accepted (r = 0.27; P = 0.007) and stunting (r = 0.4; P feeding style and stunting. Nutrition interventions that reinforce messages of optimal infant and young child feeding and integrate the promotion of responsive feeding behaviors are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Survey: Did the TFP Growth Rate in Japan Decline in the 1990s?(in Japanese)

    OpenAIRE

    INUI Tomohiko; KWON Hyeog Ug

    2004-01-01

    This paper surveys the body of research grounded on a basic question "Did the total factor productivity (TFP) growth rate in Japan decline in the 1990s?" In addition, using industry-level data of the Japan Industrial Productivity Database (JIP database) we estimate the mark-ups and the degree of returns to scale and then re-estimate TFP growth rates. Most of studies reviewed in this paper show a decline in TFP growth in the 1990s at the macro-level and the industry-level. There are some studi...

  4. Decreased growth rate of P. falciparum blood stage parasitemia with age in a holoendemic population.

    Science.gov (United States)

    Pinkevych, Mykola; Petravic, Janka; Chelimo, Kiprotich; Vulule, John; Kazura, James W; Moormann, Ann M; Davenport, Miles P

    2014-04-01

    In malaria holoendemic settings, decreased parasitemia and clinical disease is associated with age and cumulative exposure. The relative contribution of acquired immunity against various stages of the parasite life cycle is not well understood. In particular, it is not known whether changes in infection dynamics can be best explained by decreasing rates of infection, or by decreased growth rates of parasites in blood. Here, we analyze the dynamics of Plasmodium falciparum infection after treatment in a cohort of 197 healthy study participants of different ages. We use both polymerase chain reaction (PCR) and microscopy detection of parasitemia in order to understand parasite growth rates and infection rates over time. The more sensitive PCR assay detects parasites earlier than microscopy, and demonstrates a higher overall prevalence of infection than microscopy alone. The delay between PCR and microscopy detection is significantly longer in adults compared with children, consistent with slower parasite growth with age. We estimated the parasite multiplication rate from delay to PCR and microscopy detections of parasitemia. We find that both the delay between PCR and microscopy infection as well as the differing reinfection dynamics in different age groups are best explained by a slowing of parasite growth with age.

  5. Linear study of Kelvin-Helmholtz instability for a viscous compressible fluid

    International Nuclear Information System (INIS)

    Hallo, L.; Gauthier, S.

    1992-01-01

    The linear phase of the process leading to a developed turbulence is particularly important for the study of flow stability. A Galerkin spectral method adapted to the study of the mixture layer of one fluid is proposed from a sheared initial velocity profile. An algebraic mapping is developed to improve accuracy near high gradient zone. Validation is obtained by analytic methods for non-viscous flow and multi-domain spectral methods for viscous and compressible flow. Rates of growth are presented for subsonic and slightly supersonic flow. An extension of the method is presented for the study of the linear stability of a mixture with variable concentration and transport properties

  6. Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

    Directory of Open Access Journals (Sweden)

    Arike Liisa

    2011-02-01

    Full Text Available Abstract Background Lactococcus lactis is recognised as a safe (GRAS microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth. Results Using glucose limited continuous cultivations, specific growth rate dependent metabolism of L. lactis including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of L. lactis became more efficient with rising specific growth rate in the range 0.10 - 0.60 h-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. L. lactis global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in L. lactis were presumably under allosteric control. Conclusions The current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of L. lactis which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product

  7. The associations between adult body composition and abdominal adiposity outcomes, and relative weight gain and linear growth from birth to age 22 in the Birth to Twenty Plus cohort, South Africa.

    Directory of Open Access Journals (Sweden)

    Alessandra Prioreschi

    Full Text Available The growing prevalence of overweight and obesity in low- or middle-income countries precipitates the need to examine early life predictors of adiposity.To examine growth trajectories from birth, and associations with adult body composition in the Birth to Twenty Plus Cohort, Soweto, South Africa.Complete data at year 22 was available for 1088 participants (536 males and 537 females. Conditional weight and height indices were generated indicative of relative rate of growth between years 0-2, 2-5, 5-8, 8-18, and 18-22. Whole body composition was measured at year 22 (range 21-25 years using dual energy x-ray absorptiometry (DXA. Total fat free soft tissue mass (FFSTM, fat mass, and abdominal visceral adipose tissue (VAT and subcutaneous adipose tissue (SAT were recorded.Birth weight was positively associated with FFSTM and fat mass at year 22 (β = 0.11, p<0.01 and β = 0.10, p<0.01 respectively. Relative weight gain from birth to year 22 was positively associated with FFSTM, fat mass, VAT, and SAT at year 22. Relative linear growth from birth to year 22 was positively associated with FFSTM at year 22. Relative linear growth from birth to year 2 was positively associated with VAT at year 22. Being born small for gestational age and being stunted at age 2 years were inversely associated with FFSTM at year 22.The importance of optimal birth weight and growth tempos during early life for later life body composition, and the detrimental effects of pre- and postnatal growth restriction are clear; yet contemporary weight-gain most strongly predicted adult body composition. Thus interventions should target body composition trajectories during childhood and prevent excessive weight gain in early adulthood.

  8. Effect of deposition conditions on the growth rate and electrical properties of ZnO thin films grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Roro, K.T.; Botha, J.R.; Leitch, A.W.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2008-07-01

    ZnO thin films have been grown on glass substrates by MOCVD. The effect of deposition conditions such as VI/II molar ratio, DEZn flow rate and total reactor pressure on the growth rate and electrical properties of the films was studied. It is found that the growth rate decreases with an increase in the VI/II molar ratio. This behaviour is ascribed to the competitive adsorption of reactant species on the growth surface. The growth rate increases with an increase in DEZn flow rate, as expected. It is shown that the carrier concentration is independent of the DEZn flow rate. An increase in the total reactor pressure yields a decrease in growth rate. This phenomenon is attributed to the depletion of the gas phase due to parasitic prereactions between zinc and oxygen species at high pressure. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. EFFECTS OF INTEREST RATE DEREGULATION ON AGRICULTURAL FINANCE AND GROWTH IN NIGERIA

    Directory of Open Access Journals (Sweden)

    Louis O. ONYISHI

    2015-03-01

    Full Text Available The study examined the effects of interest rate deregulation on agricultural finance and growth in Nigeria. The study specifically ascertained the factors that determine the aggregate credit volume to agriculture within the periods of regulation and deregulation in the Nigerian economy, determined the effects of government finance interventions on agricultural sector performance in the Nigerian economy, determined the periodic effects of macroeconomic financial indicators on Agriculture’s gross domestic product (GDP contribution to Nigerian economy and estimated the level of real credit growth of agricultural finance in Nigeria. Descriptive statistics, Ordinary Least Squares (OLS regression technique and chow test were used for data analysis. The chow test showed that there was a significant differential effect on the aggregate credit volume to agricultural sector between the regulated and deregulated regimes. Interest rate was an important determinant of aggregate credit volume to the agricultural sector in Nigeria, especially during the deregulated period but monetary authorities should ensure appropriate determination of interest rate level that will break the double-edge effect of interest rates on savers and investors.

  10. Influence of nutrition on ovulation rate and testicular growth of Merino sheep

    International Nuclear Information System (INIS)

    Rowe, J.B.

    1988-01-01

    The effect of nutrition on reproductive performance was studied in a series of experiments using two models. Increased supply of nutrients was based on feeding lupin grain as a supplement and measurements of testicular growth or ovulation rates were used to measure reproductive characteristics. Purified sources of protein and energy were provided to determine the macronutrient(s), supplied with lupin feeding, responsible for initiating increases in testicular growth and ovulation rate. Increases in both of these parameters were closely related to the supply of additional energy but not protein. The production of acetate and glucose resulting from supplementary feeding with 750 g lupins/d was measured using infusions of 14 C tracers. Subsequently, infusions of glucose and acetate (individually and in combination) were found to produce similar increases in ovulation rate to those measured in ewes receiving lupins. It was concluded that effects of nutrition on ovulation rate are associated with increased energy intake and may be mediated through pathways linked with the synthesis and/or utilization of glucose. (author). 18 refs, 2 figs, 3 tabs

  11. Impact of delays in plutonium use on the stationary growth rate of fast breeder reactor fuel

    International Nuclear Information System (INIS)

    Borg, R.C.; Ott, K.O.

    1977-07-01

    The hierarchy of the four growth rate expressions originally derived from an instantaneous reuse scheme is expanded to account for finite burnup in the core and blanket, β-decay of 241 Pu, core and blanket loading schemes, reuse delays due to reprocessing and fabricating fuel and external fuel cycle losses. The most general growth rate expression, obtained from the asymptotic slope of the accumulating fuel material in an expanding park of breeder reactors, is formally the same in both cases. Formulation of the growth rate based on the condensation of the detailed information of the equilibrium fuel cycle for a single reactor, is more complicated than without delays due to the composition difference between the average residing and excess discharge material. The third growth rate expression results from a slightly more complicated fuel-cycle eigenvalue problem than without delays. The last definition employs isotopic breeding worth factors obtained from the adjoint fuel cycle eigenvalue problem

  12. Estimating spatially distributed monthly evapotranspiration rates by linear transformations of MODIS daytime land surface temperature data

    Directory of Open Access Journals (Sweden)

    J. Szilagyi

    2009-05-01

    Full Text Available Under simplifying conditions catchment-scale vapor pressure at the drying land surface can be calculated as a function of its watershed-representative temperature (<Ts> by the wet-surface equation (WSE, similar to the wet-bulb equation in meteorology for calculating the dry-bulb thermometer vapor pressure of the Complementary Relationship of evaporation. The corresponding watershed ET rate, , is obtained from the Bowen ratio with the help of air temperature, humidity and percent possible sunshine data. The resulting (<Ts>, pair together with the wet-environment surface temperature (<Tws> and ET rate (ETw, obtained by the Priestley-Taylor equation, define a linear transformation on a monthly basis by which spatially distributed ET rates can be estimated as a sole function of MODIS daytime land surface temperature, Ts, values within the watershed. The linear transformation preserves the mean which is highly desirable. <Tws>, in the lack of significant open water surfaces within the study watershed (Elkhorn, Nebraska, was obtained as the mean of the smallest MODIS Ts values each month. The resulting period-averaged (2000–2007 catchment-scale ET rate of 624 mm/yr is very close to the water-balance derived ET rate of about 617 mm/yr. The latter is a somewhat uncertain value due to the effects of (a observed groundwater depletion of about 1m over the study period caused by extensive irrigation, and; (b the uncertain rate of net regional groundwater supply toward the watershed. The spatially distributed ET rates correspond well with soil/aquifer properties and the resulting land use type (i.e. rangeland versus center-pivot irrigated crops.

  13. Constant growth rate can be supported by decreasing energy flux and increasing aerobic glycolysis

    NARCIS (Netherlands)

    Slavov, Nikolai; Budnik, Bogdan A; Schwab, David; Airoldi, Edoardo M; van Oudenaarden, Alexander

    2014-01-01

    Fermenting glucose in the presence of enough oxygen to support respiration, known as aerobic glycolysis, is believed to maximize growth rate. We observed increasing aerobic glycolysis during exponential growth, suggesting additional physiological roles for aerobic glycolysis. We investigated such

  14. Productivity dynamics of Livestock in southern peninsular India: A Compound growth rate analysis

    Directory of Open Access Journals (Sweden)

    G. Kathiravan 1 and S. Selvam 2

    2011-04-01

    Full Text Available Although India possesses the large volume of livestock, their productivity is abysmally low at global level. India, with its wide variation in geo-ecological parameters, elucidates a high variation in the productivity of its livestock, among regions. The compound growth rate of livestock productivity was worked out for the Southern Peninsular state of India, Tamil Nadu. The average productivity of milk in cross bred cows and buffaloes in Tamil Nadu was less than the national average, while the productivity desi cows was a bit a more. The annual compound growth rate of milk productivity among crossbred cows of Tamil Nadu was at meager 0.54 per cent during the period between 1998-1999 and 2006- 2007, whereas the productivity of milk in desi cows had improved from at an annual compound growth rate of 1.29 per cent. Notably, the milk productivity in buffaloes had declined at a rate of 0.29 per cent during the period under study. The annual compound growth of egg productivity in improved hens of Tamil Nadu was 20.87 per cent. The average annual productivity was 109.531 eggs, which improved from 70.623 in 1998-1999 to 197.084 in 2004-2005. Correspondingly, the productivity of desi hens also had a positive swing from the year 2003-2004 onwards. The results implied that the simulation of increased productivity, better farm financing and improved milk marketing could result in enhanced livestock production that would meet the future demands. [Veterinary World 2011; 4(2.000: 68-74

  15. Influence of growth rate and onset of boar contact on puberty attainment of replacement gilts raised in Thailand.

    Science.gov (United States)

    Roongsitthichai, Atthaporn; Olanratmanee, Em-On; Tummaruk, Padet

    2014-10-01

    This study aimed to investigate the influence of growth rate and onset of boar contact on age at first observed estrus of the replacement gilts raised in Thailand. In total, 766 gilts were measured for body weight and backfat thickness prior to insemination. Body weight was further calculated for growth rate. Estrus detection was performed twice a day by back pressure test with an existence of mature boars with high libido. The first date of boar exposure and that of first observed estrus were individually recorded. Due to growth rate, they were classified into three groups: high (>700 g/day), moderate (600-700 g/day), and low (<600 g/day). According to onset of boar contact, the gilts were grouped into two categories: early (<150 days) and late (≥150 days). The results revealed that the gilts expressed first observed estrus, averagely, at age 205.1 ± 34.1 days, had a growth rate of 615.5 ± 57.6 g/day, and first contact with boars at 160.7 ± 19.9 days of age. The gilts with low growth rate expressed first estrus later than those with moderate (208.6 ± 2.0 vs 198.0 ± 3.2 days, P = 0.033) and high growth rate (208.6 ± 2.0 vs 193.9 ± 6.7 days, P = 0.005) groups. Together with the influence of boar exposure, the gilts contacted boar earlier with high growth rate showed first estrus at age 180.3 ± 10.1 days, whereas those with later boar contact with low growth rate showed first estrus at age 197.9 ± 3.2 days. In summary, the replacement gilts should have high growth rate and contact boar early to attain puberty faster and possess decent subsequent reproductive performance.

  16. Dual substrate feedback control of specific growth-rate in vaccine production

    NARCIS (Netherlands)

    Neeleman, R.; Beuvery, E.C.; Vries, D.; Straten, van G.; Boxtel, van A.J.B.

    2004-01-01

    Abstract: Unexpectedly, primary concern of bio-pharmaceutical industry is not optimisation of product yield or cost reduction, but consistency in production and product quality. This paper describes the methodology and experimental results of specific growth-rate control for vaccine production. The

  17. Calculating second derivatives of population growth rates for ecology and evolution

    NARCIS (Netherlands)

    Shyu, E.; Caswell, H.

    2014-01-01

    Second derivatives of the population growth rate measure the curvature of its response to demographic, physiological or environmental parameters. The second derivatives quantify the response of sensitivity results to perturbations, provide a classification of types of selection and provide one way

  18. Parameter spaces for linear and nonlinear whistler-mode waves

    International Nuclear Information System (INIS)

    Summers, Danny; Tang, Rongxin; Omura, Yoshiharu; Lee, Dong-Hun

    2013-01-01

    We examine the growth of magnetospheric whistler-mode waves which comprises a linear growth phase followed by a nonlinear growth phase. We construct time-profiles for the wave amplitude that smoothly match at the transition between linear and nonlinear wave growth. This matching procedure can only take place over a limited “matching region” in (N h /N 0 ,A T )-space, where A T is the electron thermal anisotropy, N h is the hot (energetic) electron number density, and N 0 is the cold (background) electron number density. We construct this matching region and determine how the matching wave amplitude varies throughout the region. Further, we specify a boundary in (N h /N 0 ,A T )-space that separates a region where only linear chorus wave growth can occur from the region in which fully nonlinear chorus growth is possible. We expect that this boundary should prove of practical use in performing computationally expensive full-scale particle simulations, and in interpreting experimental wave data

  19. Experimental design and estimation of growth rate distributions in size-structured shrimp populations

    International Nuclear Information System (INIS)

    Banks, H T; Davis, Jimena L; Ernstberger, Stacey L; Hu, Shuhua; Artimovich, Elena; Dhar, Arun K

    2009-01-01

    We discuss inverse problem results for problems involving the estimation of probability distributions using aggregate data for growth in populations. We begin with a mathematical model describing variability in the early growth process of size-structured shrimp populations and discuss a computational methodology for the design of experiments to validate the model and estimate the growth-rate distributions in shrimp populations. Parameter-estimation findings using experimental data from experiments so designed for shrimp populations cultivated at Advanced BioNutrition Corporation are presented, illustrating the usefulness of mathematical and statistical modeling in understanding the uncertainty in the growth dynamics of such populations

  20. Growth of ZrSiO4 single crystal by flux method

    International Nuclear Information System (INIS)

    Ushio, Masumi; Nishitani, Yoshinari

    1982-01-01

    ZrSiO 4 single crystals were grown from the Na 2 O.3 V 2 O 5 fluxed melt at constant soaking temperatures of 900 0 C and 1000 0 C for periods up to 1710h, using the natural zircon seeds. Temperature difference between the seed and nutrient was 0.5 -- 5 0 C. A solubility curve of the natural zircon in Na 2 O.3 V 2 O 5 was determined. It was found that about 5.7g of the natural crystal dissolved in Na 2 O.3 V 2 O 5 in 48h at 1000 0 C and about 7.5g at 1200 0 C. .the maximum growth weight was about 0.35 2 g under conditions of the temperature difference of 2 0 C and the soaking for 1205h at 1000 0 C. The grown crystal was initially bounded with the c-, m-, p-, a-planes and very small planes consisting of the u- and x-, and finally bounded with the m- and p-planes. The observed linear growth rates of planes of ZrSiO 4 single crystals were in the following order:a(100) > c(001) > p(111) > m(110). The growth rates of a- and m-planes were about 5 -- 7 x 10 -4 mm/h and 0.9 -- 1.0 x 10 -4 mm/h, respectively. The growth hillocks of rounded triangular shape and elliptic shape extended to the direction of c-axis, were observed on the p- and m-planes, respectively. The observed step distence of the spiral and the step height were about 0.97 5 μm and 0.17 2 μm, respectively. The observed linear rate of advance of the step on the m-plane was about 0.4 0 -- 1.2 x 10 -8 cm/s. A linear growth rate of the m-plane was then calculated to be 0.2 5 -- 0.7 1 x 10 -4 mm/h by the BCF theory, which agreed in order of magnitude with the observes growth rate of the m-plabe. (author)

  1. Temperature and sowing date affect the linear increase of sunflower harvest index

    International Nuclear Information System (INIS)

    Bange, M.P.; Hammer, G.L.; Rickert, K.G.

    1998-01-01

    The linearity of daily linear harvest index (HI) increase can provide a simple means to predict grain growth and yield in field crops. However, the stability of the rate of increase across genotypes and environments is uncertain. Data from three field experiments were collated to investigate the phase of linear HI increase of sunflower (Helianthus annuus L.) across environments by changing genotypes, sowing time, N level, and solar irradiation level. Linear increase in HI was similar among different genotypes, N levels, and radiation treatments (mean 0.0125 d-1), but significant differences occurred between sowings. The linear increase in HI was not stable at very low temperatures (down to 9 degrees C) during grain filling, due to possible limitations to biomass accumulation and translocation (mean 0.0091 d-1). Using the linear increase in HI to predict grain yield requires predictions of the duration from an thesis to the onset of linear HI increase (lag phase) and the cessation of linear HI increase. These studies showed that the lag phase differed, and the linear HI increase ceased when 91% of the anthesis to physiological maturity period had been completed

  2. Assessing a relationship between bone microstructure and growth rate: a fluorescent labelling study in the king penguin chick (Aptenodytes patagonicus).

    Science.gov (United States)

    de Margerie, E; Robin, J-P; Verrier, D; Cubo, J; Groscolas, R; Castanet, J

    2004-02-01

    Microstructure-function relationships remain poorly understood in primary bone tissues. The relationship between bone growth rate and bone tissue type, although documented in some species by previous works, remains somewhat unclear and controversial. We assessed this relationship in a species with extreme adaptations, the king penguin (Aptenodytes patagonicus). These birds have a peculiar growth, interrupted 3 months after hatching by the austral winter. Before this interruption, chicks undergo extremely rapid statural and ponderal growth. We recorded experimentally (by means of fluorescent labelling) the growth rate of bone tissue in four long bones (humerus, radius, femur and tibiotarsus) of four king penguin chicks during their fastest phase of growth (3-5 weeks after hatching) and identified the associated bone tissue types ('laminar', 'longitudinal', 'reticular' or 'radial' fibro-lamellar bone tissue). We found the highest bone tissue growth rate known to date, up to 171 microm day(-1) (mean 55 microm day(-1)). There was a highly significant relationship between bone tissue type and growth rate (P<10(-6)). Highest rates were obtained with the radial microarchitecture of fibro-lamellar bone, where cavities in the woven network are aligned radially. This result supports the heuristic value of a relationship between growth rate and bone primary microstructure. However, we also found that growth rates of bone tissue types vary according to the long bone considered (P<10(-5)) (e.g. growth rates were 38% lower in the radius than in the other long bones), a result that puts some restriction on the applicability of absolute growth rate values (e.g. to fossil species). The biomechanical disadvantages of accelerated bone growth are discussed in relation to the locomotor behaviour of the chicks during their first month of life.

  3. Black Hole Growth Is Mainly Linked to Host-galaxy Stellar Mass Rather Than Star Formation Rate

    Science.gov (United States)

    Yang, G.; Chen, C.-T. J.; Vito, F.; Brandt, W. N.; Alexander, D. M.; Luo, B.; Sun, M. Y.; Xue, Y. Q.; Bauer, F. E.; Koekemoer, A. M.; Lehmer, B. D.; Liu, T.; Schneider, D. P.; Shemmer, O.; Trump, J. R.; Vignali, C.; Wang, J.-X.

    2017-06-01

    We investigate the dependence of black hole accretion rate (BHAR) on host-galaxy star formation rate (SFR) and stellar mass (M *) in the CANDELS/GOODS-South field in the redshift range of 0.5≤slant zteam through spectral energy distribution fitting. The average BHAR is correlated positively with both SFR and M *, and the BHAR-SFR and BHAR-M * relations can both be described acceptably by linear models with a slope of unity. However, BHAR appears to be correlated more strongly with M * than SFR. This result indicates that M * is the primary host-galaxy property related to supermassive black hole (SMBH) growth, and the apparent BHAR-SFR relation is largely a secondary effect due to the star-forming main sequence. Among our sources, massive galaxies ({M}* ≳ {10}10{M}⊙ ) have significantly higher BHAR/SFR ratios than less massive galaxies, indicating that the former have higher SMBH fueling efficiency and/or higher SMBH occupation fraction than the latter. Our results can naturally explain the observed proportionality between {M}{BH} and M * for local giant ellipticals and suggest that their {M}{BH}/{M}* is higher than that of local star-forming galaxies. Among local star-forming galaxies, massive systems might have higher {M}{BH}/{M}* compared to dwarfs.

  4. Micronutrient supplementation of young stunted Beninese children: effects on appetite and growth performance

    NARCIS (Netherlands)

    Dossa, R.A.M.

    2001-01-01

    Linear growth retardation (stunting) still has a high prevalence rate in developing countries (ACC/SCN, 2000). In the republic of Benin reported prevalence rates range from 25% to 40%. In malnourished children it is quite common to observe a combination of multiple micronutrient deficiency,

  5. Growth of Laser Initiated Damage in Fused Silica at 527 nm

    International Nuclear Information System (INIS)

    Norton, M A; Donohue, E E; Hollingsworth, W G; McElroy, J N; Hackel, R P

    2003-01-01

    The effective lifetime of optics is limited by both laser-induced damage and the subsequent growth of laser initiated damage sites. We have measured the growth rate of laser-induced damage in fused silica in both air and vacuum at 527 nm. For damage on the exit surface, the data shows exponential growth in the lateral size of the damage site with shot number. The exponential growth coefficient depends linearly on the laser fluence. The behavior at the fluence threshold for growth is contrasted to that observed at 351 nm. The growth rate was not significantly affected by either the wavelength of the initiating fluence or the presence of 10 torr of air as compared to vacuum. When the damage is located on the input surface, it has both a higher threshold for growth and does not grow exponentially

  6. The effect of temperature, salinity and growth rate on the stable hydrogen isotopic composition of long chain alkenones produced by Emiliania huxleyi and Gephyrocapsa oceanica

    Directory of Open Access Journals (Sweden)

    S. Schouten

    2006-01-01

    Full Text Available Two haptophyte algae, Emiliania huxleyi and Gephyrocapsa oceanica, were cultured at different temperatures and salinities to investigate the impact of these factors on the hydrogen isotopic composition of long chain alkenones synthesized by these algae. Results showed that alkenones synthesized by G. oceanica were on average depleted in D by 30 compared to those of E. huxleyi when grown under similar temperature and salinity conditions. The fractionation factor, αalkenones-H2O, ranged from 0.760 to 0.815 for E. huxleyi and from 0.741 to 0.788 for G. oceanica. There was no significant correlation of αalkenones-H2O with temperature but a positive linear correlation was observed between αalkenones-H2O and salinity with ~3 change in fractionation per salinity unit and a negative correlation between αalkenones-H2O and growth rate. This suggests that both salinity and growth rate can have a substantial impact on the stable hydrogen isotopic composition of long chain alkenones in natural environments.

  7. Astragalus Extract Mixture HT042 Increases Longitudinal Bone Growth Rate by Upregulating Circulatory IGF-1 in Rats

    Directory of Open Access Journals (Sweden)

    Donghun Lee

    2017-01-01

    Full Text Available Astragalus extract mixture HT042 is a standardized ingredient of health functional food approved by Korean FDA with a claim of “height growth of children.” HT042 stimulates bone growth rate and increases local IGF-1 expression in growth plate of rats which can be considered as direct stimulation of GH and its paracrine/autocrine actions. However, it remains unclear whether HT042 stimulates circulatory IGF-1 which also plays a major role to stimulate bone growth. To determine the effects on circulatory IGF-1, IGF-1 and IGFBP-3 expressions and phosphorylation of JAK2/STAT5 were evaluated in the liver after 10 days of HT042 administration. HT042 upregulated liver IGF-1 and IGFBP-3 mRNA expression, IGF-1 protein expression, and phosphorylation of JAK2/STAT5. HT042 also increased bone growth rate and proliferative zonal height in growth plate. In conclusion, HT042 stimulates bone growth rate via increment of proliferative rate by upregulation of liver IGF-1 and IGFBP-3 mRNA followed by IGF-1 protein expression through phosphorylation of JAK2/STAT5, which can be regarded as normal functioning of GH-dependent endocrine pathway.

  8. The Balance of Payments Constraint as an Explanation of International Growth Rate Differences

    Directory of Open Access Journals (Sweden)

    Anthony P. Thirlwall

    2011-12-01

    Full Text Available The paper shows that if long-run balance of payments equilibrium on current account is a requirement then a country's long run growth rate can be approximated by the ratio of the growth of exports to the income elasticity of demand for imports. The model fits well the experience of eighteen OECD countries. It is output, not relative prices, that adjusts the balance of payments, contrary to the neoclassical orthodoxy. Growth can be demand constained by the balance of payments.

  9. Growth rate of dislocation loop in Fe-Ni-Cr alloy under Kr+ ion and electron irradiation

    International Nuclear Information System (INIS)

    Kimoto, T.; Allen, C.W.; Rehn, L.E.

    1991-10-01

    In order to examine the effect of irradiating particle species on the growth rate of radiation-induced dislocation loops, a solution-annealed Fe-25Ni-15Cr-0.02C alloy was irradiated at 723 K first by 1.5 MeV Kr + ions for 2520 sec, then by 1.5 MeV Kr + ions and 1.0 MeV electrons simultaneously for 780 sec, and finally by 1.0 MeV electrons for 780 sec with the HVEM-Tandem Facility in Argonne National Laboratory. The calculated damage rate by 1.5 MeV Kr + ions was 5.8 x 10 -4 dpa/s, and that by 1.0 MeV electrons was 1 x 10 -4 dpa/s. The growth rate of a dislocation loop located at the center of the specimen was 7 x 10 -3 nm/s for the Kr + ion irradiation, 4 x 10 -2 nm/s for the simultaneous Kr + and electron irradiation, and (2--3) x 10 -2 nm/s for the electron irradiation. This implies that the electron irradiation is about 19 times more effective in the growth of radiation-induced dislocation loops than the Kr + ion irradiation. The dislocation loop growth rate under the simultaneous Kr + and electron irradiation is higher than the sum of the growth rates under the individual Kr + and electron irradiations. 5 refs., 4 figs

  10. Selection for growth rate and body size have altered the expression profiles of somatotropic axis genes in chickens

    Science.gov (United States)

    Liu, Yong; Xu, Zhiqiang; Duan, Xiaohua; Li, Qihua; Dou, Tengfei; Gu, Dahai; Rong, Hua; Wang, Kun; Li, Zhengtian; Talpur, Mir Zulqarnain; Huang, Ying; Wang, Shanrong; Yan, Shixiong; Tong, Huiquan; Zhao, Sumei; Zhao, Guiping; Su, Zhengchang; Ge, Changrong

    2018-01-01

    The growth hormone / insulin-like growth factor-1 (GH/IGF-1) pathway of the somatotropic axis is the major controller for growth rate and body size in vertebrates, but the effect of selection on the expression of GH/IGF-1 somatotropic axis genes and their association with body size and growth performance in farm animals is not fully understood. We analyzed a time series of expression profiles of GH/IGF-1 somatotropic axis genes in two chicken breeds, the Daweishan mini chickens and Wuding chickens, and the commercial Avian broilers hybrid exhibiting markedly different body sizes and growth rates. We found that growth rate and feed conversion efficiency in Daweishan mini chickens were significantly lower than those in Wuding chickens and Avian broilers. The Wuding and Daweishan mini chickens showed higher levels of plasma GH, pituitary GH mRNA but lower levels of hepatic growth hormone receptor (GHR) mRNA than in Avian broilers. Daweishan mini chickens showed significantly lower levels of plasma IGF-1, thigh muscle and hepatic IGF-1 mRNA than did Avian broilers and Wuding chickens. These results suggest that the GH part of the somatotropic axis is the main regulator of growth rate, while IGF-1 may regulate both growth rate and body weight. Selection for growth performance and body size have altered the expression profiles of somatotropic axis genes in a breed-, age-, and tissue-specific manner, and manner, and alteration of regulatory mechanisms of these genes might play an important role in the developmental characteristics of chickens. PMID:29630644

  11. Proposal of fatigue crack growth rate curve in air for nickel-base alloys used in BWR

    International Nuclear Information System (INIS)

    Ogawa, Takuya; Itatani, Masao; Nagase, Hiroshi; Aoike, Satoru; Yoneda, Hideki

    2013-01-01

    When the defects are detected in the nuclear components in Japan, structural integrity assessment should be performed for the technical judgment on continuous service based on the Rules on Fitness-for-Service for Nuclear Power Plants of the Japan Society of Mechanical Engineers Code (JSME FFS Code). Fatigue crack growth analysis is required when the cyclic loading would be applied for the components. Recently, fatigue crack growth rate curve in air environment for Nickel-base alloys weld metal used in BWR was proposed by the authors and it was adopted as a code case of JSME FFS Code to evaluate the embedded flaw. In this study, fatigue crack growth behavior for heat-affected zone (HAZ) of Nickel-base alloys in air was investigated. And a unified fatigue crack growth rate curve in air for HAZ and weld metal of Nickel-base alloys used in BWR was evaluated. As a result, it was found that the curve for weld metal could be applied as a curve for both HAZ and weld metal since moderately conservative assessment of fatigue crack growth rate of HAZ is possible by the curve for weld metal in the Paris region. And the threshold value of stress intensity far range (ΔK th ) is determined to 3.0 MPa√m based on the fatigue crack growth rate of HAZ. (author)

  12. Does raking basal duff affect tree growth rates or mortality?

    Science.gov (United States)

    Erin Noonan-Wright; Sharon M. Hood; Danny R. Cluck

    2010-01-01

    Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure...

  13. Growth Rate and Health Status of Weaned Rabbits Fed Ensiled ...

    African Journals Online (AJOL)

    In a 6 week feeding experiment, twenty five New Zealand white breed of weaned rabbits, with an average age of 8-10 weeks were used to assess the effect of ensiled water hyacinth (WH) with different additives on growth rate and blood parameters of the animals. The animals were randomly allotted to five dietary groups, ...

  14. Short-term lower-leg growth rate and urine cortisol excretion in children treated with ciclesonide

    DEFF Research Database (Denmark)

    Agertoft, Lone; Pedersen, Søren

    2005-01-01

    BACKGROUND: Measurement of short-term lower-leg growth rate in children by means of knemometry has become established as an integral part of the available measures of systemic activity of topical steroids in children. OBJECTIVE: We sought to determine the effects of clinically effective doses....... There was no statistically significant dose-response effect. Likewise, no statistically significant differences or dose-response effects were found for urinary cortisol adjusted for creatinine. CONCLUSION: Short-term lower-leg growth rate and hypothalamic-pituitary-adrenal axis function are not affected by treatment...... of the novel inhaled corticosteroid ciclesonide on lower-leg growth rate and hypothalamic-pituitary-adrenal axis function in children with asthma. METHODS: In a double-blind, placebo-controlled, 4-period crossover study, 24 children aged 6 to 12 years sequentially received ciclesonide (40, 80, and 160 microg...

  15. Dispersion relation and growth in a two-stream free electron laser with helical wiggler and ion channel guiding

    International Nuclear Information System (INIS)

    Mehdian, Hassan; Abbasi, Negar

    2008-01-01

    A linear theory of two-stream free electron laser (FEL) with helical wiggler and ion channel guiding is presented. The dispersion relation is obtained with the help of fluid theory and the growth rate is analyzed through the numerical solutions. The considerable enhancement of the growth rate is demonstrated due to the two-stream instability and continuous tuning of peak growth rate ratio, two-stream FEL compared to single-stream FEL, in terms of varying the ion channel frequency is illustrated

  16. EFFECT OF POST-LOGGING SILVICULTURAL TREATMENT ON GROWTH RATES OF RESIDUAL STAND IN A TROPICAL FOREST

    Directory of Open Access Journals (Sweden)

    Haruni Krisnawati

    2010-12-01

    Full Text Available Post-logging silvicultural treatments are generally performed to improve yields of the remaining tree species by increasing their growth rate. In this study the effects of silvicultural treatment on the growth rates of commercial (dipterocarps and non-dipterocarps as well as non- commercial tree species in a tropical forest in West Kalimantan were examined and were compared to a control treatment. Silvicultural treatment applied was liberation of future crop trees from lianas and neighbouring competing trees. Treatments were applied to six plots of 80 m x 80 m each. The plots comprised 64 quadrats of 10 m x 10 m to allow better control of measurements. The treatment and control plots were established 6 years after logging. Effects were measured 2,4 and 7 years after treatment application. In all obser vation periods, the growth rates increased with silvicultural treatment. Overall, commercial dipterocarps, commercial non-dipterocarps and non-commercial tree species groups differed in response to silvicultural treatment. The growth rates of commercial tree species in plots that received silvicultural treatment were 62–97% higher than in the control plots. For non-commercial tree species, the increase of growth rates was 20–58%, compared to the control plots. These results indicate that the application of silvicultural treatments after logging could help improve the growth of the residual stands. These provide quantitative information that silvicultural treatments in logged-over forest should be considered as a viable management option and may guide the choice of cutting cycle.

  17. Rate-Compatible Protograph LDPC Codes

    Science.gov (United States)

    Nguyen, Thuy V. (Inventor); Nosratinia, Aria (Inventor); Divsalar, Dariush (Inventor)

    2014-01-01

    Digital communication coding methods resulting in rate-compatible low density parity-check (LDPC) codes built from protographs. Described digital coding methods start with a desired code rate and a selection of the numbers of variable nodes and check nodes to be used in the protograph. Constraints are set to satisfy a linear minimum distance growth property for the protograph. All possible edges in the graph are searched for the minimum iterative decoding threshold and the protograph with the lowest iterative decoding threshold is selected. Protographs designed in this manner are used in decode and forward relay channels.

  18. Slow crack growth in post-consumer recycled high-density polyethylene

    OpenAIRE

    Sciammarella, Cesar A.; Yang, Y.

    2015-01-01

    An experimental study of slow crack growth behavior of post-consumer recycled high-density polyethylene blended with virgin high-density polyethylene copolymer has been done. The study has been performed under constant load and in baths of distilled water at 40, 60, 80°C. The specimen used is notched with side grooves. The test results of crack growth have been analyzed using linear fracture mechanics and the rate process theory. The results show that the resistance to crack growth increases ...

  19. Towards establishing a combined rate law of nucleation and crystal growth - The case study of gypsum precipitation

    Science.gov (United States)

    Rendel, Pedro M.; Gavrieli, Ittai; Wolff-Boenisch, Domenik; Ganor, Jiwchar

    2018-03-01

    The main obstacle in the formulation of a quantitative rate-model for mineral precipitation is the absence of a rigorous method for coupling nucleation and growth processes. In order to link both processes, we conducted a series of batch experiments in which gypsum nucleation was followed by crystal growth. Experiments were carried out using various stirring methods in several batch vessels made of different materials. In the experiments, the initial degree of supersaturation of the solution with respect to gypsum (Ωgyp) was set between 1.58 and 1.82. Under these conditions, heterogeneous nucleation is the dominant nucleation mode. Based on changes in SO42- concentration with time, the induction time of gypsum nucleation and the following rate of crystal growth were calculated for each experiment. The induction time (6-104 h) was found to be a function of the vessel material, while the rates of crystal growth, which varied over three orders of magnitude, were strongly affected by the stirring speed and its mode (i.e. rocking, shaking, magnetic stirrer, and magnetic impeller). The SO42- concentration data were then used to formulate a forward model that couples the simple rate laws for nucleation and crystal growth of gypsum into a single kinetic model. Accordingly, the obtained rate law is based on classical nucleation theory and heterogeneous crystal growth.

  20. Prediction of PWSCC in nickel base alloys using crack growth rate models

    International Nuclear Information System (INIS)

    Thompson, C.D.

    1995-01-01

    The Ford/Andresen slip dissolution SCC model, originally developed for stainless steel components in BWR environments, has been applied to Alloy 600 and Alloy X-750 tested in deaerated pure water chemistry. A method is described whereby the crack growth rates measured in compact tension specimens can be used to estimate crack growth in a component. Good agreement was found between model prediction and measured SCC in X-750 threaded fasteners over a wide range of temperatures, stresses, and material condition. Most data support the basic assumption of this model that cracks initiate early in life. The evidence supporting a particular SCC mechanism is mixed. Electrochemical repassivation data and estimates of oxide fracture strain indicate that the slip dissolution model can account for the observed crack growth rates, provided primary rather than secondary creep rates are used. However, approximately 100 cross-sectional TEM foils of SCC cracks including crack tips reveal no evidence of enhanced plasticity or unique dislocation patterns at the crack tip or along the crack to support a classic slip dissolution mechanism. No voids, hydrides,, or microcracks are found in the vicinity of the crack tips creating doubt about classic hydrogen related mechanisms. The bulk oxide films exhibit a surface oxide which is often different than the oxide found within a crack. Although bulk chromium concentration affects the rate of SCC, analytical data indicates the mechanism does not result from chromium depletion at the grain boundaries. The overall findings support a corrosion/dissolution mechanism but not one necessarily related to slip at the crack tip. (author). 12 refs, 27 figs