A Provincial View of Capital Mobility

This paper develops a method of testing for zones of financial integration based upon intertemporal considerations and applies it to data on Canadian provincial trade. In a financially-integrated region individuals smooth consumption with respect to movements in aggregate income. Consumption in that region follows income in that region if individuals use only regional capital markets while consumption follows movements in income in broader regions (e.g. national income or world income) if individuals have access to and use capital markets in those broader regions (e.g. the national or global capital markets, respectively). We derive a specification which measures the impact of differential levels of access to capital markets--different zones of capital mobility--on the relationship between the regional trade balance and regional, national and global income. This empirical specification is tested using data on trade balances across Canadian provinces. The results indicate full capital mobility within Canada but only partial capital mobility between Canada and the rest of the world.

Effect of nisin on the keeping quality of feta cheese

In an attempt to extend cheese shelf-life, nisin was added to Feta cheese during cheese making to achieve a final concentration of 40 lU/ml ofmilk. At this concentration, acid production was slightlyretarded afterthe curd cutting but not completely inhibited. Cheese manufacture proceeded apparently normally yielding a product that met Greek regulatory standards. Chemical analysis showed that nisin addition had no significant effect (P<0.01) on salt, fat or ash contents. However, the total chee se dry matter was significantly reduced. The 8helf-life was shortened to less than 47 days due to intensive growth of Gram negative bacteria not inhibited by nisin. Such organisms were probably stimulated by the inhibition of competitive Gram positive bacteria incIuding, the starter culture, to sorne extent. The shelf-life of the control cheese exceeded 60 days.Résumé:Effet de la nisine sur la conservabilité du fromage FetaDans une tentative d'extension de la durée de conservation du fromage "Feta", la nisine lui a été ajoutée durant sa fabrication à une concentration finale de 40 UI/ml de lait. À cette concentration, la production d'acide a été légèrement affectée après coupure du caillé sans être complètement inhibée. La fabrication du fromage a continué apparemment normalement aboutissant à un produit conforme aux normes grecs. L'analyse chimique a révélé que l'addition de nisine n'avait pas d'effet significatif (P<O,Ol) sur les teneurs en sel, matière grasse et cendres. Cependant, le taux de matière sèche a été significativement réduit. La durée de conservation a été réduite à moins de 47 jours à cause d'une croissance intensive des bactéries à Gram négatif qui ne sont pas inhibées par la nisine. La croissance de ces bactéries a été probablement favorisée par l'inhibition, à un certain degré, des bactéries à Gram positif compétitives comprenant celles du ferment. La durée de conservation du témoin (fromage sans ajout de nisine) a, en revanche, dépassé les 60 jours

An Immune Basis for Malaria Protection by the Sickle Cell Trait

BACKGROUND: Malaria resistance by the sickle cell trait (genotype HbAS) has served as the prime example of genetic selection for over half a century. Nevertheless, the mechanism of this resistance remains the subject of considerable debate. While it probably involves innate factors such as the reduced ability of Plasmodium falciparum parasites to grow and multiply in HbAS erythrocytes, recent observations suggest that it might also involve the accelerated acquisition of malaria-specific immunity. METHODS AND FINDINGS: We studied the age-specific protection afforded by HbAS against clinical malaria in children living on the coast of Kenya. We found that protection increased with age from only 20% in the first 2 y of life to a maximum of 56% by the age of 10 y, returning thereafter to 30% in participants greater than 10 y old. CONCLUSIONS: Our observations suggest that malaria protection by HbAS involves the enhancement of not only innate but also of acquired immunity to the parasite. A better understanding of the underlying mechanisms might yield important insights into both these processes

Unseeded Elastomeric Single Leaflets Retain Function and Remodel After Implant In Ovine Pulmonary Outflow Tract

Current materials for heart valve replacement and repair are limited by the inability to grow or remodel. Tissue engineered valves offer the potential to overcome these disadvantages by creating living structures, but is limited by the availability of biocompatible scaffold materials with desirable biomechanical properties. We assessed the in vivo performance of a novel scaffold poly(carbonate urethane) urea (PCUU), fabricated by electrospinning and implanted in the pulmonary outflow tract of sheep. PCUU was electrospun into elastomeric sheets of thickness ranging from 120-180 μm. Using cardiopulmonary bypass we replaced the native anterior pulmonary leaflet with an acellular PCUU leaflet. Valve function was evaluated by epicardial echocardiography at implant and explant at weeks 1 (n=3), 3 (n=3), 6 (n=3) and 16 (n=3). Histological, immunohistochemical, molecular imaging analyses and multi-photon imaging were performed on the explanted leaflets. Echocardiography demonstrated mobile functioning leaflets, with zero to mild pulmonary regurgitation. Molecular imaging showed increased levels of proteolytic activity and macrophage accumulation. Histology showed persistence of scaffold material up to 16 weeks with cellular infiltration throughout the leaflet. Picrosirius red revealed mature collagen deposition along the arterial surface of the construct at 6 and 16 weeks. These findings were corroborated by multi-photon analysis showing highly aligned collagen fibers across the leaflets. Both surfaces of the engineered leaflets were consistently covered with CD31 positive cells. The majority of cells expressed α-SMA and MMP2. CD45 positive cells, suggesting hematogenous origin, were found throughout the leaflet. These results suggest that: 1) PCUU can be a suitable polymer for valve bioengineering; 2) cell pre-seeding may not be required for tissue formation or remodeling for a functional engineered valve; 3) host cells seem to populate the leaflet either by migration from adjacent tissue or by attachment from circulating blood; 4) mature matrix orientation and increased proteolytic activity suggests active tissue remodeling. Longer term implants and the role of scaffold pre-seeding will require further study

Characterization of the commercially-available fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a marker for chloroquine resistance and uptake in a 96-well plate assay

Chloroquine was a cheap, extremely effective drug against Plasmodium falciparum until resistance arose. One approach to reversing resistance is the inhibition of chloroquine efflux from its site of action, the parasite digestive vacuole. Chloroquine accumulation studies have traditionally relied on radiolabelled chloroquine, which poses several challenges. There is a need for development of a safe and biologically relevant substitute. We report here a commercially-available green fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a proxy for chloroquine accumulation. This compound localized to the digestive vacuole of the parasite as observed under confocal microscopy, and inhibited growth of chloroquine-sensitive strain 3D7 more extensively than in the resistant strains 7G8 and K1. Microplate reader measurements indicated suppression of LynxTag-CQGREEN efflux after pretreatment of parasites with known reversal agents. Microsomes carrying either sensitive or resistant-type PfCRT were assayed for uptake; resistant-type PfCRT exhibited increased accumulation of LynxTag-CQGREEN, which was suppressed by pretreatment with known chemosensitizers. Eight laboratory strains and twelve clinical isolates were sequenced for PfCRT and Pgh1 haplotypes previously reported to contribute to drug resistance, and pfmdr1 copy number and chloroquine IC50s were determined. These data were compared with LynxTag-CQGREEN uptake/fluorescence by multiple linear regression to identify genetic correlates of uptake. Uptake of the compound correlated with the logIC50 of chloroquine and, more weakly, a mutation in Pgh1, F1226Y