The gene complement of the ancestral bilaterian - was Urbilateria a monster?

Expressed sequence tag analyses of the annelid Pomatoceros lamarckii, recently published in BMC Evolutionary Biology, are consistent with less extensive gene loss in the Lophotrochozoa than in the Ecdysozoa, but it would be premature to generalize about patterns of gene loss on the basis of the limited data available

Productivity Growth in U.S. Agriculture

Innovation and changes in technology have been a driving force for gains in productivity growth in U.S. agriculture. USDA's Economic Research Service has developed annual indexes of agricultural inputs, outputs, and total factor productivity (TFP) for 1948 through 2004. American agriculture relies almost entirely on productivity growth to raise output. By lowering the cost of agricultural commodities, productivity growth benefits not only farmers but also food manufacturers and consumers.Agriculture, productivity, productivity growth, total factor productivity, TFP, labor, farm economy, prices, agricultural research, agricultural output, technology, ERS, USDA, Production Economics, Productivity Analysis,

U.S. Agriculture, 1960-96 A Multilateral Comparison of Total Factor Productivity

This study provides estimates of the growth and relative levels of agricultural productivity for the 48 contiguous States for the period 1960 to 1996. For the full 1960-96 period, every State exhibits a positive and generally substantial average annual rate of productivity growth. There is considerable variance, however. The wide disparity in growth rates resulted in substantial changes in the ranking order of States by productivity. For each year, we calculate the coefficient of variation of productivity levels. We use these coefficients to show that the range of levels of productivity has narrowed over time, although the pattern of convergence was far from uniform. The fact that in some States, productivity grew faster than others and yet the cross-section dispersion decreased, implies that the States whose productivity grew most rapidly were those with lower initial levels of productivity. This result is consistent with Gerschenkron's notion of the advantage of relative backwardness. The States that were particularly far behind the productivity leaders had the most to gain from the diffusion of technical knowledge and proceeded to grow most rapidly. We also observe a positive relation between capital accumulation and productivity growth, implying embodiment of technology in capital.production accounts, multilateral index numbers, total factor productivity, Productivity Analysis,

Land Quality in an International Comparison: It's Importance in Measuring Productivity

The purpose of this paper has been to present quality-adjusted values for land in the United States and nine European countries using price and quantity data for 1990. Disregarding such differences in the quality-adjusted land input would generate biased estimates of the land input and thus of total factor productivity. Land quality adjustments could potentially be enhanced further with additional data on soil characteristics, climate, and other productivity-related characteristics.total factor productivity, hedonic techniques, soil stress, quality-adjusted land, Productivity Analysis,

Productivity Growth and Convergence in U.S. Agriculture: New Cointegration Panel Data Results

Dynamic effects of health and inter-state and inter-industry knowledge spillovers, total factor productivity (TFP) growth and convergence in U.S. agriculture are examined using recently developed procedures for panel data and a growth accounting model. Strong evidence is found to support the hypothesis that TFP converges to a steady-state. Health care supply in rural areas and research spillovers from other states and from nonagricultural sectors are found to have significant impacts on the productivity growth rate both in the short-run and long-run. These results suggest richer opportunities for policymakers to enhance productivity growth.convergence, growth, pooled mean group estimator, total factor productivity

Agricultural productivity in the United States: catching-up and the business cycle

This paper examines the relation between the business cycle and convergence in levels of total factor productivity (TFP) across states. First, we find evidence of convergence in TFP levels across the different phases of the business cycle, but the speed of convergence was much greater during periods of contraction in economic activity than during periods of expansion. Second, we find that technology embodied in capital was an important source of productivity growth in agriculture. As with the rate of catch-up, the embodiment effect was much stronger during low economic activity phases of the business cycle.Agriculture, Convergence, Total factor productivity

The gene complement of the ancestral bilaterian - was Urbilateria a monster?

Expressed sequence tag analyses of the annelid Pomatoceros lamarckii, recently published in BMC Evolutionary Biology, are consistent with less extensive gene loss in the Lophotrochozoa than in the Ecdysozoa, but it would be premature to generalize about patterns of gene loss on the basis of the limited data available

Differential expression of three galaxin-related genes during settlement and metamorphosis in the scleractinian coral Acropora millepora

BACKGROUND: The coral skeleton consists of CaCO3 deposited upon an organic matrix primarily as aragonite. Currently galaxin, from Galaxea fascicularis, is the only soluble protein component of the organic matrix that has been characterized from a coral. Three genes related to galaxin were identified in the coral Acropora millepora. RESULTS: One of the Acropora genes (Amgalaxin) encodes a clear galaxin ortholog, while the others (Amgalaxin-like 1 and Amgalaxin-like 2) encode larger and more divergent proteins. All three proteins are predicted to be extracellular and share common structural features, most notably the presence of repetitive motifs containing dicysteine residues. In situ hybridization reveals distinct, but partially overlapping, spatial expression of the genes in patterns consistent with distinct roles in calcification. Both of the Amgalaxin-like genes are expressed exclusively in the early stages of calcification, while Amgalaxin continues to be expressed in the adult, consistent with the situation in the coral Galaxea. CONCLUSION: Comparisons with molluscs suggest functional convergence in the two groups; lustrin A/pearlin proteins may be the mollusc counterparts of galaxin, whereas the galaxin-like proteins combine characteristics of two distinct proteins involved in mollusc calcification. Database searches indicate that, although sequences with high similarity to the galaxins are restricted to the Scleractinia, more divergent members of this protein family are present in other cnidarians and some other metazoans. We suggest that ancestral galaxins may have been secondarily recruited to roles in calcification in the Triassic, when the Scleractinia first appeared. Understanding the evolution of the broader galaxin family will require wider sampling and expression analysis in a range of cnidarians and other animals

Incorporating Environmental Impacts in the Measurement of Agricultural Productivity Growth

Agricultural production is known to have environmental impacts, both adverse and beneficial, and it is desirable to incorporate at least some of these impacts in an environmentally sensitive productivity index. In this paper, we construct indicators of water contamination from the use of agricultural chemicals. These environmental indicators are merged with data on marketed outputs and purchased inputs to form a state-by-year panel of relative levels of outputs and inputs, including environmental impacts. We do not have prices for these undesirable by products, since they are not marketed. Consequently, we calculate a series of Malmquist productivity indexes, which do not require price information. Our benchmark scenario is a conventional Malmquist productivity index based on marketed outputs and purchased inputs only. Our comparison scenarios consist of environmentally sensitive Malmquist productivity indexes that include indicators of risk to human health and to aquatic life from chronic exposure to pesticides. In addition, we derive a set of virtual prices of the undesirable by-products that can be used to calculate an environmentally sensitive Fisher index of productivity change.environmental impacts, productivity growth, Environmental Economics and Policy,