Dynamic contrast-enhanced magnetic resonance imaging reveals stress-induced angiogenesis in MCF7 human breast tumors.

The mechanism of contrast enhancement of tumors using magnetic resonance imaging was investigated in MCF7 human breast cancer implanted in nude mice. Dynamic contrast-enhanced images recorded at high spatial resolution were analyzed by an image analysis method based on a physiological model, which included the blood circulation, the tumor, the remaining tissues, and clearance via the kidneys. This analysis enabled us to map in rapidly enhancing regions within the tumor, the capillary permeability factor (capillary permeability times surface area per voxel volume) and the fraction of leakage space. Correlation of these maps with T2-weighted spin echo images, with histopathology, and with immunohistochemical staining of endothelial cells demonstrated the presence of dense permeable microcapillaries in the tumor periphery and in intratumoral regions that surrounded necrotic loci. The high leakage from the intratumoral permeable capillaries indicated an induction of a specific angiogenic process associated with stress conditions that cause necrosis. This induction was augmented in tumors responding to tamoxifen treatment. Determination of the distribution and extent of this stress-induced angiogenic activity by contrast-enhanced MRI might be of diagnostic and of prognostic value.

Key Issues and Developments in Farmland Sales Markets in the EU Member States and Candidate Countries. Factor Markets Working Paper No. 12, February 2012

This paper describes recent developments in sales markets of agricultural land in selected member states of the European Union and its candidate countries. Analysis focuses on the importance of the sales market for agricultural land, the average size of transacted plots, and the evolution and magnitude of the land sales prices. The share of agricultural land sold on the market is relatively stable in most of the old member states, with the exception of Finland, the Netherlands and the UK, where a more dynamic market is observed. For the new member states, the sales market for agricultural land is strongly affected by public sales under the ongoing land privatisation programmes, while strong variation prevails in the private sales market. Substantial differences are also observed in both the average size of the transacted plots and the sales prices. For the latter, price regulations partially explain the heterogeneity in the evolution of sales prices.

Does the Common Agricultural Policy Reduce Farm Labour Migration? Panel data analysis across EU regions. Factor Markets Working Paper No. 28, July 2012

This paper deals with the determinants of labour out-migration from agriculture across 149 EU regions over the 1990–2008 period. The central aim is to shed light on the role played by payments from the common agricultural policy (CAP) on this important adjustment process. Using static and dynamic panel data estimators, we show that standard neoclassical drivers, like relative income and the relative labour share, represent significant determinants of the intersectoral migration of agricultural labour. Overall, CAP payments contributed significantly to job creation in agriculture, although the magnitude of the economic effect was rather moderate. We also find that pillar I subsidies exerted an effect approximately two times greater than that of pillar II payments.

Identifying Factor Productivity from Micro-data: The case of EU agriculture. Factor Markets Working Paper No. 34, January 2013

The classical problem of agricultural productivity measurement has regained interest owing to recent price hikes in world food markets. At the same time, there is a new methodological debate on the appropriate identification strategies for addressing endogeneity and collinearity problems in production function estimation. We examine the plausibility of four established and innovative identification strategies for the case of agriculture and test a set of related estimators using farm-level panel datasets from seven EU countries. The newly suggested control function and dynamic panel approaches provide attractive conceptual improvements over the received ‘within’ and duality models. Even so, empirical implementation of the conceptual sophistications built into these estimators does not always live up to expectations. This is particularly true for the dynamic panel estimator, which mostly failed to identify reasonable elasticities for the (quasi-) fixed factors. Less demanding proxy approaches represent an interesting alternative for agricultural applications. In our EU sample, we find very low shadow prices for labour, land and fixed capital across countries. The production elasticity of materials is high, so improving the availability of working capital is the most promising way to increase agricultural productivity.

RED vs. REDD: Biofuel Policy vs. Forest Conservation. Factor Markets Working Document No. 41, May 2013

This paper assesses the complex interplay between global Renewable Energy Directives (RED) and the United Nations programme to Reduce Emissions from Deforestation and forest Degradation (REDD). We examine the interaction of the two policies using a scenario approach with a recursive-dynamic global Computable General Equilibrium model. The consequences of a global biofuel directive on worldwide land use, agricultural production, international trade flows, food prices and food security out to 2030 are evaluated with and without a strict global REDD policy. We address a key methodological challenge of how to model the supply of land in the face of restrictions over its availability, as arises under the REDD policy. The paper introduces a flexible land supply function, which allows for large changes in the total potential land availability for agriculture. Our results show that whilst both RED and REDD are designed to reduce emissions, they have opposing impacts on land use. RED policies are found to extend land use whereas the REDD policy leads to an overall reduction in land use and intensification of agriculture. Strict REDD policies to protect forest and woodland lead to higher land prices in all regions. World food prices are slightly higher overall with some significant regional increases, notably in Southern Africa and Indonesia, leading to reductions in food security in these countries. This said, real food prices in 2030 are still lower than the 2010 level, even with the RED and REDD policies in place. Overall this suggests that RED and REDD are feasible from a worldwide perspective, although the results show that there are some regional problems that need to be resolved. The results show that countries directly affected by forest and woodland protection would be the most economically vulnerable when the REDD policy is implemented. The introduction of REDD policies reduces global trade in agricultural products and moves some developing countries to a net importing position for agricultural products. This suggests that the protection of forests and woodlands in these regions reverses their comparative advantage as they move from being land-abundant to land-scarce regions. The full REDD policy setting, however, foresees providing compensation to these countries to cover their economic losses.

Investment behaviour of EU arable crop farms in selected EU countries and the impact of policy reforms. Factor Markets Working Document No. 42, May 2013

This deliverable provides a comparative analysis, among selected EU member states, of the investment demand of a sample of specialised field crop farms for farm buildings, machinery and equipment as determined by different types and levels of Common Agricultural Policy support. It allows for the existence of uncertainty in the price of output farmers receive and for both long- and short-run determinants of investment levels, as well as for the presence of irregularities in the cost adjustment function due to the existence of threshold-type behaviours. The empirical estimation reveals that three investment regimes are consistently identified in Germany and Hungary, across asset and support types, and in France for machinery and equipment. More traditional disinvestment-investment type behaviours characterise investment in farm building in France and the UK, across support types, and Italy for both asset classes under coupled payments. The long-run dynamic adjustment of capital stocks is consistently and significantly estimated to be towards a – mostly non-stationary – lower level of capitalisation of the farm analysed. By contrast, the expected largely positive short-run effects of an increase in output prices are often not significant. The effect of CAP support on both types of investment is positive, although seldom significant, while the proxy for uncertainty employed fails to be significant yet, in most cases, has the expected effect of reducing the investment levels.

Simulation Results of AgriPoliS about Diminishing Capital Subsidies and Restrictions. Factor Markets Working Document No. 55, June 2013

This paper investigates the impacts of high interest rates for borrowed capital and credit restrictions on the structural development of four European regions. The method used is the model AgriPoliS which is a spatial-dynamic agent-based model. It is able to provide aggregated results at the regional level, but very individual results as well by considering farms as independent entities. Farms can choose between different investment options during the simulation. Several scenarios with different interest rates for borrowed capital on the one hand as well as with different levels of credit restrictions on the other hand are tested and compared. Results show that higher interest rates have less impact on declining production branches than on expanding ones. If they have the possibility farms invest in the most profitable production branch which relative profitability might have changed with high interest rates. Credit restrictions lead farms to choose smaller and cheaper investments than expensive and large ones. Results also show that income losses in both cases due to under-investment compared to the reference situation are partially compensated by lower rental prices. The impacts on structural change also differ depending on the region and the initial situation. In summary, credit subsidies or imperfections on credit markets might have indirect impacts on the type of dominant investment and therefore on the whole regional agricultural sector as well.

The Impact of CAP Reforms on Farm Labour Structure. Factor Markets Working Document No. 63, August 2013

The labour force engaged in the agricultural sector is declining over time, and one can observe the reallocation of labour from family members to hired workers. Using farm-level data, this paper analyses the on-farm labour structure in Greece and assesses the factors driving its evolution over the period 1990-2008. The impact of agricultural policies and farm characteristics is examined in a dynamic panel analysis. Family and hired labour are found to be substitutes rather than complements, while agricultural support measures appear to negatively affect demand for both family and hired labour. Decoupled payments and subsidies on crops are found to have a significant impact on both sources of labour, as well as subsidies for rural development that do not favour on-farm labour use. The paper also finds that structural labour adjustments are the result of farm characteristics, such as farm size and location. The results are robust to various estimation techniques and specifications.

An Analysis of the Capitalisation of CAP Payments into Land Rental Rates in Ireland. Factor Markets Working Document No. 68, August 2013

EDITED VERSION SOON TO BE PUBLISHED In this paper the effect of decoupling on the capitalisation of agricultural subsidies into agricultural rents in Ireland are analysed using a dynamic rental equations estimated with a two step system GMM estimator that accounts for expectation error and endogenous regressors. The findings illustrate the importance of institutional details in determining the extent to which subsidies are capitalised. In the period prior to decoupling Pillar 1 subsidies were highly capitalised into Irish agricultural rents in both the short and the long run. Depending on the farm system considered between 58 to 80 cents per euro of subsidies were capitalised into agricultural rents. In the post decoupling period the rate at which Pillar 1 subsidies are capitalised into Irish agricultural rents is found to have declined. This change is likely due to short term character of the Irish agricultural land rental market, where 11 month rental periods predominate, and the freedom that the 2003 reform of the CAP offered farmers to consolidate entitlements established on rented land. The generally very short term nature of Irish agricultural rental contracts offered farmers an opportunity to consolidate entitlements that is unlikely to have arisen in other Member States with agricultural land rental markets characterised by long term contracts. The results in both the pre and post decoupling periods highlight the high degree of inertia of agricultural rents in Ireland, and the importance of accounting for dynamics when investigating the capitalisation of agricultural subsidies into land rents. The high degree of inertia in rents means that the impact of previously capitalised agricultural policy persists through time.

Trade policy in a dynamic Heckscher-Ohlin model

The Import Substitution Process in Latin Amer ica was an attempt to enhance GDP growth and productivity by rising trade barriers upon capital-intensive products. Our main goal is to analyze how an increase in import tariff on a particular type of good affects the production choices and trade pattern of an economy. We develop an extension of the dynamic Heckscher-Ohlin model – a combination of a static two goods, two-factor Heckscher-Ohlin model and a two-sector growth model – allowing for import tariff. We then calibrate the closed economy model to the US. The results show that the economy will produce less of both consumption and investment goods under autarky for low and high levels of capital stock per worker. We also find that total GDP may be lower under free trade in comparison to autarky.

Dynamic Management of Loyalty Program Strategies

Thesis (Ph.D.)--University of Washington, 2016-06

Prediction of protein B-factor profiles

The polypeptide backbones and side chains of proteins are constantly moving due to thermal motion and the kinetic energy of the atoms. The B-factors of protein crystal structures reflect the fluctuation of atoms about their average positions and provide important information about protein dynamics. Computational approaches to predict thermal motion are useful for analyzing the dynamic properties of proteins with unknown structures. In this article, we utilize a novel support vector regression (SVR) approach to predict the B-factor distribution (B-factor profile) of a protein from its sequence. We explore schemes for encoding sequences and various settings for the parameters used in SVR. Based on a large dataset of high-resolution proteins, our method predicts the B-factor distribution with a Pearson correlation coefficient (CC) of 0.53. In addition, our method predicts the B-factor profile with a CC of at least 0.56 for more than half of the proteins. Our method also performs well for classifying residues (rigid vs. flexible). For almost all predicted B-factor thresholds, prediction accuracies (percent of correctly predicted residues) are greater than 70%. These results exceed the best results of other sequence-based prediction methods. (C) 2005 Wiley-Liss, Inc.

Definition and spatial annotation of the dynamic secretome during early kidney development

The term secretome has been defined as a set of secreted proteins (Grimmond et al. [2003] Genome Res 13:1350-1359). The term secreted protein encompasses all proteins exported from the cell including growth factors, extracellular proteinases, morphogens, and extracellular matrix molecules. Defining the genes encoding secreted proteins that change in expression during organogenesis, the dynamic secretome, is likely to point to key drivers of morphogenesis. Such secreted proteins are involved in the reciprocal interactions between the ureteric bud (UB) and the metanephric mesenchyme (AM) that occur during organogenesis of the metanephros. Some key metanephric secreted proteins have been identified, but many remain to be determined. In this study, microarray expression profiling of E10.5, E11.5, and E13.5 kidney and consensus bioinformatic analysis were used to define a dynamic secretome of early metanephric development. In situ hybridisation was used to confirm microarray results and clarify spatial expression patterns for these genes. Forty-one secreted factors were dynamically expressed between the E10.5 and E13.5 timeframe profiled, and 25 of these factors had not previously been implicated in kidney development. A text-based anatomical ontology was used to spatially annotate the expression pattern of these genes in cultured metanephric explants.

The impact of supply chain performance measurement systems on dynamic behaviour in supply chains

The amplification of demand variation up a supply chain widely termed ‘the Bullwhip Effect’ is disruptive, costly and something that supply chain management generally seeks to minimise. Originally attributed to poor system design; deficiencies in policies, organisation structure and delays in material and information flow all lead to sub-optimal reorder point calculation. It has since been attributed to exogenous random factors such as: uncertainties in demand, supply and distribution lead time but these causes are not exclusive as academic and operational studies since have shown that orders and/or inventories can exhibit significant variability even if customer demand and lead time are deterministic. This increase in the range of possible causes of dynamic behaviour indicates that our understanding of the phenomenon is far from complete. One possible, yet previously unexplored, factor that may influence dynamic behaviour in supply chains is the application and operation of supply chain performance measures. Organisations monitoring and responding to their adopted key performance metrics will make operational changes and this action may influence the level of dynamics within the supply chain, possibly degrading the performance of the very system they were intended to measure. In order to explore this a plausible abstraction of the operational responses to the Supply Chain Council’s SCOR® (Supply Chain Operations Reference) model was incorporated into a classic Beer Game distribution representation, using the dynamic discrete event simulation software Simul8. During the simulation the five SCOR Supply Chain Performance Attributes: Reliability, Responsiveness, Flexibility, Cost and Utilisation were continuously monitored and compared to established targets. Operational adjustments to the; reorder point, transportation modes and production capacity (where appropriate) for three independent supply chain roles were made and the degree of dynamic behaviour in the Supply Chain measured, using the ratio of the standard deviation of upstream demand relative to the standard deviation of the downstream demand. Factors employed to build the detailed model include: variable retail demand, order transmission, transportation delays, production delays, capacity constraints demand multipliers and demand averaging periods. Five dimensions of supply chain performance were monitored independently in three autonomous supply chain roles and operational settings adjusted accordingly. Uniqueness of this research stems from the application of the five SCOR performance attributes with modelled operational responses in a dynamic discrete event simulation model. This project makes its primary contribution to knowledge by measuring the impact, on supply chain dynamics, of applying a representative performance measurement system.

Dynamic measurement of accommodative responses while viewing stereoscopic images

Using video refraction accommodative and convergence dynamic responses were measured to stepped changes in convergence stimuli with unchanged accommodative stimuli (conflicting stereoscopic image) and compared with responses to non-conflicting target stimuli. Three targets were used that varied in their spatial frequency components. An accommodative transient overshoot was evident in four out of seven subjects for only conflicting stimuli. One showed accommodative and convergence oscillation probably due to difficulty in fusing the stereoscopic target when it had a higher spatial component, however, this oscillation diminished when the target was spatial low-pass filtered. We hypothesise that transient responses to step stimuli is initiated by convergence-driven accommodation and subsequently followed by slower fine-control of accommodation modulated by the amount of blur. Inter-subject differences in convergence-driven accommodation may also be a factor to consider. For stereoscopic stimuli, it is proposed that the increase in blur immediately after the onset of the accommodative response inhibits cessation of the response.