Misalignment mechanism for a mass-varying vector boson

A coherent field over the entire universe is an attractive picture in studying the dark sector of the universe. The misalignment mechanism, which relies on inflation to achieve homogeneousness of the field, is a popular mechanism for producing such a coherent dark matter. Nevertheless, unlike a scalar field case, a vector boson field suffers because its energy density is exponentially suppressed by the scale factor during the cosmic expansion. We show that if the vector field gets a mass from a scalar field, whose value increases by orders of magnitude, the suppression can be compensated, and the misalignment can produce the coherent vector boson that has a sizable amount of energy density in the present universe. Quintessence can be such a scalar field.Comment: 23 pages, 6 figure

Inhibitory activity of the peptides derived from buffalo prolactin on angiogenesis

The peptide fragments obtained by cathepsin digestion of purified buffalo prolactin (buPRL) monomer have been characterized using SDS-PAGE and FPLC with regard to size and pI. Their antiangiogenic activity was tested in chick embryo chorioallantoic membrane (CAM) assay and the human endothelial cells wound healing assay. Antiangiogenic activity was observed in cathepsin-cleaved fragments from buPRL. Further, a peptide sequence 45A- 46Q-47G-48K-49G-50F-51I-52T-53M-54A-55L-56N-57S-58C, which matched with human somatostatin (hSST), a known antiangiogenic factor, was located in the second loop between the first and second a-helices in the threedimensional structure of buPRL, obtained by homology modelling. The synthetic peptide matching with SST sequence was found to exhibit antiangiogenic activity in both in vitro and ex vivo assays. It was also observed that all the peptides related to buPRL could antagonize the vascular endothelial growth factor (VEGF) and bradykinin (BK)- dependent production of endothelial nitric oxide (NO), which is a pre-requisite for endothelial tube formation. It is concluded therefore that an internal sequence in buPRL and peptide fragments derived from cathepsin-digested buPRL exhibit antiangiogenic activities

THE URUGUAY ROUND AGREEMENT ON AGRICULTURE: AN EVALUATION

Contact for this paper: Laura Bipes/University of Minnesota/Department of Applied Economics/ 1994 Buford Avenue./ St. Paul, MN 55108 USA. From the start, agriculture played a central role in the Uruguay Round of GATT trade negotiations. The Punta del Este Declaration called for a solution to the problems facing agricultural trade through modified trade rules and an agreement to lower protection levels. It was recognized that such an improvement implied negotiations on the national farm policies as well as just trade policies. The time that it took to reach agreement reflected the political sensitivity and technical complexity of this task. The Agreement embodied in the Final Act of the Uruguay Round breaks new ground for agriculture, and takes a big step towards placing this sector of world trade under rules more consistent with those in operation in other areas. However, the degree of liberalization of markets is modest, and much remains to be done in future rounds of negotiations. The most far-reaching element in the Agreement is a change in the rules regarding market access. With very few exceptions, all participating countries have agreed to convert all existing non-tariff barriers (along with unbound tariffs) into bound duties and not to introduce new non-tariff measures. Negotiations agreed to reduce these new bound tariffs, as well as tariffs already bound earlier, according to Schedules included as a part of the Agreement. "Tariffication" will impose changes in import policies for a number of countries. Canada will replace import quotas for dairy and poultry products with tariffs, initially at a high level. The European Union will replace its variable levy with tariffs, though a maximum duty-paid price for cereals has been negotiated which puts a limit on the tariff charged. Latin American countries have generally engaged in tariffication in recent years in advance of the Uruguay Round Agreement: for these, and other countries their tariffs will now be bound. The US will forgo the use of Section 22 import quotas and the negotiation of voluntary export restraint agreements with beef suppliers, but the impact on these markets is likely to be small. Japan and Korea have been allowed to delay tariffication in the case of rice for the next few years. The Agreement provides in cases of tariffication for "minimum access opportunities", to guard against the impact of high initial tariff rates. This will open up reduced-tariff quotas for a number of products including beef, cereals and fruits and vegetables. The quotas will be expanded to about 5 percent of consumption over the 6 year period. Japan and Korea have agreed to a greater expansion of market access for rice in compensation for the delay in introducing tariffs. The ability of countries to control export subsidies in agricultural markets was one of the main issues under discussion in the negotiation. Under the Agreement, countries accept commitments on reducing expenditure on export subsidies as well on the quantity of subsidized exports. This will limit export subsidies by the EU and other countries, for such products as wheat, dairy products and beef, and should lead to firmer world market prices in these commodities. These quantities are also expressed in the Schedules which form part of the Agreement. Countries have also agreed not to apply export subsidies to commodities not subsidized in the base period. The Agreement also sets rules and commitments for domestic support policies. It defines a set of policies which are deemed to be less trade-distorting than others, and allocates them to a "green box" which is broadly immune to challenge. Other policies not sheltered in this way are subject to reduction through a limit on the total support given by domestic subsidies and administered prices. It was decided that neither the U.S. deficiency payments (under current legislation) nor the new hectarage compensation payments under the reformed Common Agricultural Policy of the EU need to be reduced. It was also agreed that subsidies that conform to the new rules are sheltered from international challenge under the GATT. Developing Countries generally face less stringent commitments, having 10 years rather than six to make the changes, and having to meet only two-thirds of the reduction targets. In addition, development policies are included broadly in the "green box". Along with the provisions on domestic and trade policies in the Agreement, participants also concluded an Agreement on Sanitary and Phytosanitary Measures (SPS Agreement). The goal was to make it easier to distinguish between genuine health and safety issues and disguised protection. The right of countries to set their own safety and health standards is reaffirmed, but with the provision that such standards should be based on scientific justification and that use be made of international standards where possible. The extent to which the Agreement will lead to greater market access, curb export subsidies and modify domestic policies in the next few years can only be determined from a detailed inspection of the Schedule of commitments made by the individual countries. Paradoxically, the immediate impact on national policies is likely in most cases to be small. Many countries have been engaged in a process of reducing government support to agriculture, and making such support more closely targetted to needs, in advance of the outcome of the Round. Policy reforms in the EU, Canada, Sweden, Australia and New Zealand, along with much of Latin America, have been strongly influenced by the negotiations in the Uruguay Round. The Agreement thus takes on the task of supporting and locking-in such reforms, and encouraging them in other countries. In some aspects the Agreement falls short of expectations (or at least initial demands). It does not constitute a major move toward free trade in agricultural products: the cost of changing the rules has been to give up some degree of liberalization. The tariffs which countries will impose in place of non-tariff barriers are in many cases so high that trade will be restricted to the agreed access quantities. Export subsidy programs will continue though at a reduced level. The major pressure to reinstrument farm policies will continue to be from domestic budget constraints. It will take further rounds of negotiations to reduce protection in agricultural markets to a level comparable to that for most manufactured products. However, with the rule changes and the new types of country commitments agreed, a much more promising basis bas been created for future negotiations.International Relations/Trade,

On the Nature of Propagating Intensity Disturbances in Polar Plumes during the 2017 Total Solar Eclipse

The propagating intensity disturbances (PIDs) in plumes are still poorly understood and their identity (magnetoacoustic waves or flows) remains an open question. We investigate PIDs in five plumes located in the northern polar coronal hole observed during the 2017 total solar eclipse. Three plumes are associated with coronal bright points, jets and macrospicules at their base (active plumes) and the other two plumes are not (quiet plumes). The electron temperature at the base of the plumes is obtained from the filter ratio of images taken with the X-ray Telescope on board Hinode and the passband ratio around 400 nm from an eclipse instrument, the Diagnostic Coronagraph Experiment (DICE). The phase speed (v_r), frequency (omega), and wavenumber (k) of the PIDs in the plumes are obtained by applying a Fourier transformation to the space-time (r-t plane) plots in images taken with the Atmospheric Imaging Assembly (AIA) in three different wavelength channels (171 A, 193 A, and 211 A). We found that the PIDs in the higher temperature AIA channels, 193 and 211 A, are faster than that of the cooler AIA 171 A channel. This tendency is more significant for the active plumes than the quiet ones. The observed speed ratio (~1.3) between the AIA 171 and 193 A channels is similar to the theoretical value (1.25) of a slow magnetoacoustic wave. Our results support the idea that PIDs in plumes represent a superposition of slow magnetoacoustic waves and plasma outflows that consist of dense cool flows and hot coronal jets.Comment: 18 pages, 8 figures, accepted for publication in Ap

The Food Security Role of Domestic Agriculture in Developing Countries and its Measurment

In this paper, the concepts and means to achieve food security with minimum costs are outlined theoretically, followed by the description of public good aspect of food security. Situations and issues regarding food security of developing countries are also explained. Nextly, a list of food security indicators are suggested based on the definition and elements of food security for the purpose of cross-country comparison of food security situation