Opportunities and constraints in schistosomiasis vaccine development: infection characteristics and industry realities

The notes provided in this article relate to two components of the development of vaccines against schistosomiasis: (1) The characteristics of schistosome infections (eg. features of the schistosome life cycle), and the parasite itself, that have implications for vaccination strategies; (2) The characteristics of the biopharmaceutical industry that have implications for product development. As will be seen, these two topic areas are not vastly disparate.

Compositional Constraints in the Extremely GC-poor Genome of Plasmodium falciparum

We have analyzed the compositional properties of coding (protein encoding) and non-coding sequences of Plasmodium falciparum, a unicellular parasite characterized by an extremely AT-rich genome. GC% levels, base and dinucleotide frequencies were studied. We found that among the various factors that contribute to the properties of the sequences analyzed, the most relevant are the compositional constraints which operate on the whole genome

The theory of constraints in manufacturing

In this paper, a systematic and quantitative view is presented for the application of the theory of constraints in manufacturing. This is done employing the operational research technique of mathematical programming. The potential of the theory of constraints in automated manufacturing is demonstrated.

MHC-restricted antigen presentation and recognition: constraints on gene, recombinant and peptide vaccines in humans

The target of any immunization is to activate and expand lymphocyte clones with the desired recognition specificity and the necessary effector functions. In gene, recombinant and peptide vaccines, the immunogen is a single protein or a small assembly of epitopes from antigenic proteins. Since most immune responses against protein and peptide antigens are T-cell dependent, the molecular target of such vaccines is to generate at least 50-100 complexes between MHC molecule and the antigenic peptide per antigen-presenting cell, sensitizing a T cell population of appropriate clonal size and effector characteristics. Thus, the immunobiology of antigen recognition by T cells must be taken into account when designing new generation peptide- or gene-based vaccines. Since T cell recognition is MHC-restricted, and given the wide polymorphism of the different MHC molecules, distinct epitopes may be recognized by different individuals in the population. Therefore, the issue of whether immunization will be effective in inducing a protective immune response, covering the entire target population, becomes an important question. Many pathogens have evolved molecular mechanisms to escape recognition by the immune system by variation of antigenic protein sequences. In this short review, we will discuss the several concepts related to selection of amino acid sequences to be included in DNA and peptide vaccines.

The debt crisis: a re-appraisal

The 1980s' debt crisis is a landmark in developing economies' growth and stabilization. According to the most quoted empirical articles, external shocks and vicissitudes gave rise to crisis just because of delays in stabilization policies, engendered by internal conflicts and institutional immaturity. I review some of these papers, and find out some problems - in the measurement of shocks and foreign indebtedness, namely - whose corrections lead to opposite results: external shocks and foreign indebtedness explain that crisis regardless of domestic policies. At the same time, the strong correlation of income distribution to terms of trade changes and foreign indebtedness suggest that inequality may have contributed differently to that crisis: either through an economic channel, or through a political channel based on delays in reforms.

The contagion effect of public debt on monetary policy: the Brazilian experience

This paper attempts to explain why the Brazilian inter-bank interest rate is so high compared with rates practiced by other emerging economies. The interplay between the markets for bank reserves and government securities feeds into the inter-bank rate the risk premium of the Brazilian public debt.

External debt in developing economies: assessment and policy issues

More than one decade after the external debt restructuring (the Brady Plan), a great amount of literature has been published concerning the balance sheet factors in developing countries. The staff of international multilateral institutions joined with reputable academics in this great controversy. The external debt problem of the developing countries is back and once more reflections on its cause and on policy recommendations are analytically distinct. Our main task is to reflect on the recent external debt dynamics and assess how this debt has evolved. Our findings indicate that the susceptibility of some developing countries to default is associated with global imbalance, that is, the way they borrow.

National exchange rate policies and international debt crises: how Brazil did not follow Argentina into a default in 2001-2002

This paper examines how exchange rate policies and IMF Stand-By Arrangements affect debt crises using econometrics and a comparison between Argentina and Brazil. It refines an existing diagram outlining crisis development to propose crisis prevention strategies. Flexible exchange rate policies reduce a country's probability of default by over 4%, but Stand-By Arrangements increase it by an inconsequential percentage. Unlike Argentina, Brazil avoided a default via a freely-floating exchange rate system, fiscal deficit reduction, and a cooperative and coordinated relationship with the IMF. The results provide policymakers from developing countries with lessons to manage their countries' default risks more effectively.

Competitividade e restrição externa na Zona do Euro

The recent debt crisis in Greece, Ireland and Portugal has exposed the fragility existing in the Eurozone for promoting development and economic convergence between the countries that have adopted the currency. Way beyond the fear of insolvency, what is observed is a growing disparity of the most-developed countries in comparison to the less-developed ones, with perverse consequences for the last ones. Once the nominal exchange rates are fixed, the divergent movements in relative prices and wages between the countries have led to totally distinct paths for the real exchange rates. Worsening the scenario, one can observe the incompleteness of the political union, the monetarist focus of the ECB and the lack of labor mobility between the countries, what distances from the argument stated by the theory and puts in jeopardize the future of the Monetary Union.