89 research outputs found
Table_1_A Thermotolerant Variant of Rubisco Activase From a Wild Relative Improves Growth and Seed Yield in Rice Under Heat Stress.DOCX
No full textGenes encoding thermostable variants of the photosynthesis heat-labile protein Rubisco activase (Rca) from a wild relative Oryza australiensis were overexpressed in domesticated rice (Oryza sativa). Proteomics was used to quantify the abundance of O. australiensis Rca (Rca-Oa) in the resulting plants. Plants were grown to maturity in growth rooms and from early tillering until immediately prior to anthesis, they were exposed to daytime maximum temperatures of 28, 40, and 45°C and constant night temperatures of 22°C. Non-destructive measurements of leaf elongation and photosynthesis were used to compare the null segregant with a transfected line in which 19% of its total Rca content was the recombinant O. australiensis Rca (T-Oa-19). Height, fresh mass, panicle number, seed set, and seed number were measured at final harvest. Traits at maturity after heat stress at 45°C correlated strongly with recombinant protein abundance. Seed number was far the most responsive trait to an increase in Rca-Oa abundance, improving by up to 150%. Leaf elongation rates (LER) and tiller number were significantly greater in the transformed plants in the first two weeks of exposure to 45°C but tiller numbers later became equal in the two genotypes. Gas exchange measurements showed that T-Oa-19 had faster light induction of photosynthesis but not significantly higher CO2 assimilation rates, indicating that the carbon gain that resulted in large yield improvement after growth at 45°C was not strongly correlated with an instantaneous measurement of steady-state photosynthesis. When plants were grown at 40°C daytime maximum, there was no improvement in the final biomass, panicle or seed number when compared with 28°C, indicating that the threshold for heat damage and beneficial effects of the thermostable Rca recombinant protein was between 40 and 45°C, which corresponded to leaf temperatures in the range 38–42°C. The results suggest that the thermotolerant form of Rca from O. australiensis was sufficient to enhance carbohydrate accumulation and storage by rice over the life of the plant, dramatically improving yields after exposure to heat throughout the vegetative phase.</p
The growth of firms: a survey of theories and empirical evidence
No full textResearch into firm growth has been accumulating at a terrific pace, and Alex Coad's survey of this multifaceted field provides a detailed, comprehensive overview of the latest developments. Much progress has been made in empirical research into firm growth in recent decades due to factors such as the availability of detailed longitudinal datasets, more powerful computers and new econometric techniques. This book provides an up-to-date catalog of empirical work, as well as a coherent theoretical structure within which these new results can be interpreted and understood. It brings together a large body of recent research on firm growth from a multidisciplinary perspective, providing an up-to-date synthesis of stylized facts and empirical regularities. Numerous empirical findings and theories of firm growth are also surveyed and compared in order to evaluate their validity. Drawing on a vast and diverse body of research, this book will prove invaluable to students, academics, policy makers and practitioners with a need to keep abreast of studies in industrial organization, firm growth and management
On the distribution of product price and quality
No full textWe investigate the structure of demand by focusing on the distribution of prices within narrowly-defined classes of goods. We observe considerable heterogeneity—products that are functionally similar but presumably of different ‘quality’ may sell at very different prices. We analyze distribution of prices for bottles of wine, used cars, houses in London and week-long holidays in Majorca, and observe in each case that the the resulting distribution is more skewed than the lognormal but less skewed than a Pareto distribution. We then present a theoretical model whereby products can distinguish themselves along multiple hedonic dimensions of ‘performance’, with these product attributes being random variables subject to multiplicative interactions. Variations of this model can reproduce a lognormal price distribution and a Pareto distribution as lower and upper bound benchmarks (respectively)
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Firms as bundles of discrete resources - towards an explanation of the exponential distribution of firm growth rates
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Neoclassical vs evolutionary theories of financial constraints: critique and prospectus
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The exponential age distribution and the Pareto firm size distribution
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Firm growth and scaling of growth rate variance in multiplant firms
No full textWhile Gibrat's Law assumes that growth rate variance is independent of size, empirical work has usually found a negative relationship between growth rate variance and firm growth. Using data on French manufacturing firms, we observe a relatively low, but statistically significant, negative relationship between firm size and growth rate variance. Furthermore, we observe that growth rate variance does not decrease monotonically the more plants a firm possesses, which is at odds with a number of theoretical model
Firm growth and scaling of growth rate variance in multiplant firms
No full textWhile Gibrats Law assumes that growth rate variance is independent of size, empirical work has usually found a negative relationship between growth rate variance and firm growth. Using data on French manufacturing firms, we observe a relatively low, but statistically significant, negative relationship between firm size and growth rate variance. Furthermore, we observe that growth rate variance does not decrease monotonically the more plants a firm possesses, which is at odds with a number of theoretical models
Testing the principle of ‘growth of the fitter’ : The relationship between profits and firm growth
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The Growth of Firms : A Survey of Theories and Empirical Evidence
No full textResearch into firm growth has been accumulating at a terrific pace, and Alex Coad's survey of this multifaceted field provides a detailed, comprehensive overview of the latest developments. Much progress has been made in empirical research into firm growth in recent decades due to factors such as the availability of detailed longitudinal datasets, more powerful computers and new econometric techniques. This book provides an up-to-date catalog of empirical work, as well as a coherent theoretical structure within which these new results can be interpreted and understood. It brings together a large body of recent research on firm growth from a multidisciplinary perspective, providing an up-to-date synthesis of stylized facts and empirical regularities. Numerous empirical findings and theories of firm growth are also surveyed and compared in order to evaluate their validity. Drawing on a vast and diverse body of research, this book will prove invaluable to students, academics, policy makers and practitioners with a need to keep abreast of studies in industrial organization, firm growth and management
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