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Affects Growth (affect + growth)

Distribution by Scientific Domains

Life Sciences	60%

Selected Abstracts

Short periods of prenatal stress affect growth, behaviour and hypothalamo,pituitary,adrenal axis activity in male guinea pig offspring

THE JOURNAL OF PHYSIOLOGY, Issue 3 2005
Amita Kapoor
Prenatal stress can have profound long-term influences on physiological function throughout the course of life. We hypothesized that focused periods of moderate prenatal stress at discrete time points in late gestation have differential effects on hypothalamo,pituitary,adrenal (HPA) axis function in adult guinea pig offspring, and that changes in HPA axis function will be associated with modification of anxiety-related behaviour. Pregnant guinea pigs were exposed to a strobe light for 2 h on gestational days (GD) 50, 51, 52 (PS50) or 60, 61, 62 (PS60) (gestation length ,70 days). A control group was left undisturbed throughout pregnancy. Behaviour was assessed in male offspring on postnatal day (PND)25 and PND70 by measurement of ambulatory activity and thigmotaxis (wall-seeking behaviour) in a novel open field environment. Subsequent to behavioural testing, male offspring were cannulated (PND75) to evaluate basal and activated HPA axis function. Body weight was significantly decreased in adult PS50 and PS60 offspring and this effect was apparent soon after weaning. The brain-to-body-weight ratio was significantly increased in adult PS50 males. Basal plasma cortisol levels were elevated in PS50 male offspring throughout the 24 h sampling period compared with controls. In response to an ACTH challenge and to exposure to an acute stressor, PS60 male offspring exhibited elevated plasma cortisol responses. Plasma testosterone concentrations were strikingly decreased in PS50 offspring. Thigmotaxis in the novel environment was increased in PS50 male offspring at PND25 and PND70, suggesting increased anxiety in these animals. In conclusion, prenatal stress during critical windows of neuroendocrine development programs growth, HPA axis function, and stress-related behaviour in adult male guinea pig offspring. Further, the nature of the effect is dependant on the timing of the maternal stress during pregnancy. [source]

Fluctuations in the incubation moisture environment affect growth but not survival of hatchling lizards

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2010
TRAVIS R. ROBBINS
Few studies have collected longitudinal data that follow the complete microevolutionary path of an organism linking sources of variation (e.g. environmental versus genetic) to a trait and its subsequent relationship with fitness. Identifying the links within this pathway is imperative for understanding the ecological relevance of effects found at the phenotypic level. Furthermore, experimental studies that examine parts of the pathway in ectothermic organisms often fail to mimic the complexities of the natural developmental environment. Temperature and moisture conditions in reptile nests, for example, can fluctuate greatly on a seasonal and daily basis. Despite the potential effects of fluctuating environments, the vast majority of studies have held environmental treatments constant during the developmental period. We investigated the effects of fluctuating moisture regimes during incubation on eggs, hatchling phenotypes, and subsequent survival in the eastern fence lizard Sceloporus undulatus. Moisture fluctuations during embryonic development caused water absorption by eggs to follow the environmental availability of moisture. Initial hatchling tail length was affected by the pattern of moisture fluctuations, and hatchling growth rates in fluctuating treatments were significantly faster than those in a constant treatment, resulting in larger hatchlings after 4 weeks. A release,recapture experiment conducted in the field did not detect a treatment effect on survival despite the larger body sizes. In summary, although fluctuations affected water absorption by eggs and some hatchling traits, these effects did not have subsequent fitness consequences. The results obtained suggest that egg and hatchling survival are buffered against natural soil moisture fluctuations during incubation, even when egg and hatchling traits are significantly affected. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 89,102. [source]

The application of ethephon (an ethylene releaser) increases growth, photosynthesis and nitrogen accumulation in mustard (Brassica juncea L.) under high nitrogen levels

PLANT BIOLOGY, Issue 5 2008
N. A. Khan
Abstract Ethephon (2-chloroethyl phosphonic acid), an ethylene-releasing compound, influences growth and photosynthesis of mustard (Brassica juncea L. Czern & Coss.). We show the effect of nitrogen availability on ethylene evolution and how this affects growth, photosynthesis and nitrogen accumulation. Ethylene evolution in the control with low N (100 mg N kg,1 soil) was two-times higher than with high N (200 mg N kg,1 soil). The application of 100,400 ,l·l,1 ethephon post-flowering, i.e. 60 days after sowing, on plants receiving low or high N further increased ethylene evolution. Leaf area, relative growth rate (RGR), photosynthesis, leaf nitrate reductase (NR) activity and leaf N reached a maximum with application of 200 ,l·l,1 ethephon and high N. The results suggest that the application of ethephon influences growth, photosynthesis and N accumulation, depending on the amount of nitrogen in the soil. [source]

Does access to credit improve productivity?

THE ECONOMICS OF TRANSITION, Issue 3 2008
Evidence from Bulgaria
Access to credit; productivity; transition Abstract Although it is widely accepted that financial development is associated with higher growth, the evidence on the channels through which credit affects growth at the microeconomic level is scant. Using data from a cross-section of Bulgarian firms, we estimate the impact of access to credit, as proxied by indicators of whether firms have access to a credit line or overdraft facility, on productivity. To overcome potential omitted variable bias of Ordinary Least Squares (OLS) estimates, we use information on firms' past growth to instrument for access to credit. We find credit to be positively and strongly associated with TFP. These results are robust to a wide range of robustness checks. [source]

Reform reversals and output growth in transition economies,

THE ECONOMICS OF TRANSITION, Issue 4 2003
Bruno Merlevede
Abstract This paper tests whether reform reversals during transition carry an economic cost. Reform is measured by an average reform index, while reform reversals are characterized by a drop in the average reform index. In the standard empirical framework the current level of reform affects growth negatively, while the lagged level affects growth positively. This non-linear effect implies a counterintuitive, short-lived positive effect of a reversal. In a simultaneous equation system with growth and the level of reform as dependent variables we explicitly introduce a reversal parameter. Empirical results suggest that reversals have an immediate negative impact on real output growth. Controlling for the level of reform shows that reversals are more costly at higher levels of reform. [source]