Bilateral Protection and Other Determinants of Trade: A Gravity Model Approach

Replaced with revised version of paper 10/03/07.International Relations/Trade,

Global Growth, Macroeconomic Change, and U.S. Agricultural Trade

After a decade of uneven export growth and rapidly growing imports, U.S. agriculture has begun to reassert its position in global trade markets. Rising exports and signs of moderating demand for imports mark a departure from previous trends. This report places past trends and emerging developments in perspective by spotlighting the role of two specific factors that help steer U.S. agricultural trade patterns: global growth and shifts in foreign economic activity that affect U.S. exports, and macroeconomic factors underlying the growth of U.S. imports. Consistent with actual changes in the level and destination of U.S. exports, model simulations corroborate the contention that renewed export growth can be sustained by expanding incomes and growing food import demand in emerging economies. In contrast, the rapid growth of U.S. agricultural imports appears less related to domestic income growth than to changing consumer preferences and other, perhaps less sustainable, macroeconomic conditions that fostered the growth of U.S. current account deficits.agricultural trade, trade balance, income growth, economic development, population, macroeconomics, exchange rates, current account, growth projections., Agricultural and Food Policy, Agricultural Finance, International Development, International Relations/Trade,

The focus of light - linear polarization breaks the rotational symmetry of the focal spot

We experimentally demonstrate for the first time that a linearly polarized beam is focussed to an asymmetric spot when using a high-numerical aperture focussing system. This asymmetry was predicted by Richards and Wolf [Proc.R.Soc.London A, 253, 358 (1959)] and can only be measured when a polarization insensitive sensor is placed in the focal region. We used a specially modified photodiode in a knife edge type set up to obtain highly resolved images of the total electric energy density distribution at the focus. The results are in good agreement with the predictions of a vectorial focussing theory.Comment: to be published in "Journal of Modern Optics

MARKET ACCESS FOR HIGH-VALUE FOODS

Market access remains a major impediment for expansion of global trade in high-value foods, particularly processed foods. Countries use tariffs and other measures that effectively stimulate imports of relatively unprocessed agricultural commodities at the expense of processed products. Tariff escalation, in which tariffs rise with the level of processing, discourages trade in high-value foods, and trade remedy measures, such as antidumping duties, are concentrated among high-value products. Globalization has provided countries with easier access to capital and technology needed to produce processed food, further affecting trade patterns and markets for high-value foods. A uniform cut in tariffs increases trade in high-value foods more than trade in raw agricultural commodities and improves real wages in developing and developed countries.Food trade, processed food, high-value foods, tariff, tariff escalation, trade remedy measures, sanitary and phytosanitary measures, safeguard measures, revealed comparative advantage, trade complementarities, International Relations/Trade,

Dry-Spun Silk Produces Native-Like Fibroin Solutions

Silk's outstanding mechanical properties and energy efficient solidification mechanisms provide inspiration for biomaterial self-assembly as well as offering a diverse platform of materials suitable for many biotechnology applications. Experiments now reveal that the mulberry silkworm Bombyx mori secretes its silk in a practically "unspun" state that retains much of the solvent water and exhibits a surprisingly low degree of molecular order (β-sheet crystallinity) compared to the state found in a fully formed and matured fiber. These new observations challenge the general understanding of silk spinning and in particular the role of the spinning duct for structure development. Building on this discovery we report that silk spun in low humidity appears to arrest a molecular annealing process crucial for β-sheet formation. This, in turn, has significant positive implications, enabling the production of a high fidelity reconstituted silk fibroin with properties akin to the gold standard of unspun native silk

Hierarchical Chain Model of Spider Capture Silk Elasticity

Spider capture silk is a biomaterial with both high strength and high elasticity, but the structural design principle underlying these remarkable properties is still unknown. It was revealed recently by atomic force microscopy that, an exponential force--extension relationship holds both for capture silk mesostructures and for intact capture silk fibers [N. Becker et al., Nature Materials 2, 278 (2003)]. In this Letter a simple hierarchical chain model was proposed to understand and reproduce this striking observation. In the hierarchical chain model, a polymer is composed of many structural motifs which organize into structural modules and supra-modules in a hierarchical manner. Each module in this hierarchy has its own characteristic force. The repetitive patterns in the amino acid sequence of the major flagelliform protein of spider capture silk is in support of this model.Comment: 4 pages, 3 figures. Will be formally published in PR

Menstrual cycle phase modulates emotional conflict processing in women with and without premenstrual syndrome (PMS): A pilot study

Background Premenstrual syndrome (PMS) is characterized by a cluster of psychological and somatic symptoms during the late luteal phase of the menstrual cycle that disappear after the onset of menses. Behavioral differences in emotional and cognitive processing have been reported in women with PMS, and it is of particular interest whether PMS affects the parallel execution of emotional and cognitive processing. Related to this is the question of how the performance of women with PMS relates to stress levels compared to women without PMS. Cortisol has been shown to affect emotional processing in general and it has also been shown that women with severe PMS have a particular cortisol profile. Methods We measured performance in an emotional conflict task and stress levels in women with PMS (n = 15) and women without PMS (n = 15) throughout their menstrual cycle. Results We found a significant increase (p = 0.001) in the mean reaction time for resolving emotional conflict from the follicular to the luteal cycle phase in all subjects. Only women with PMS demonstrated an increase in physiological and subjective stress measures during the luteal menstrual cycle phase. Conclusions Our findings suggest that the menstrual cycle modulates the integration of emotional and cognitive processing in all women. Preliminary data are supportive of the secondary hypothesis that stress levels are mediated by the menstrual cycle phase only in women with PMS. The presented evidence for menstrual cycle-specific differences in integrating emotional and cognitive information highlights the importance of controlling for menstrual cycle phase in studies that aim to elucidate the interplay of emotion and cognition

Monoclonal Antibodies to the V2 Domain of MN-rgp120: Fine Mapping of Epitopes and Inhibition of α4β7 Binding

BACKGROUND: Recombinant gp120 (MN-rgp120) was a major component of the AIDSVAX B/E vaccine used in the RV144 trial. This was the first clinical trial to show that vaccination could prevent HIV infection in humans. A recent RV144 correlates of protection study found that protection correlated with the presence of antibodies to the V2 domain. It has been proposed that antibodies to the α4β7 binding site in the V2 domain might prevent HIV-1 infection by blocking the ability of virions to recognize α4β7 on activated T-cells. In this study we investigated the specificity of monoclonal antibodies (MAbs) to the V2 domain of MN-rgp120 and examined the possibility that these antibodies could inhibit the binding of MN-rgp120 to the α4β7 integrin. METHODOLOGY/PRINCIPAL FINDINGS: Nine MAbs to the V2 domain were isolated from mice immunized with recombinant envelope proteins. The ability of these MAbs to inhibit HIV infection, block the binding of gp120 to CD4, and block the binding of MN-rgp120 to the α4β7 integrin was measured. Mutational analysis showed that eight of the MAbs recognized two immunodominant clusters of amino acids (166-168 and 178-183) located at either end of the C strand within the four-strand anti-parallel sheet structure comprising the V1/V2 domain. CONCLUSIONS/SIGNIFICANCE: These studies showed that the antigenic structure of the V2 domain is exceedingly complex and that MAbs isolated from mice immunized with MN-rgp120 exhibited a high level of strain specificity compared to MAbs to the V2 domain isolated from HIV-infected humans. We found that immunization with MN-rgp120 readily elicits antibodies to the V2 domain and some of these were able to block the binding of MN-rgp120 to the α4β7 integrin