Preferential Partners Research Articles

Engineering substrate channeling in a bifunctional terpene synthase

Fusicoccadiene synthase from Phomopsis amygdala (PaFS) is a bifunctional terpene synthase. It contains a prenyltransferase (PT) domain that generates geranylgeranyl diphosphate (GGPP) from dimethylallyl diphosphate and three equivalents of isopentenyl diphosphate, and a cyclase domain that converts GGPP into fusicoccadiene, a precursor of the diterpene glycoside Fusicoccin A. The two catalytic domains are connected by a flexible 69-residue linker. The PT domain mediates oligomerization to form predominantly octamers, with cyclase domains randomly splayed out around the PT core. Surprisingly, despite the random positioning of cyclase domains, substrate channeling is operative in catalysis since most of the GGPP generated by the PT remains on the enzyme for cyclization. Here, we demonstrate that covalent linkage of the PT and cyclase domains is not required for GGPP channeling, although covalent linkage may improve channeling efficiency. Moreover, GGPP competition experiments with other diterpene cyclases indicate that the PaFS PT and cyclase domains are preferential partners regardless of whether they are covalently linked or not. The cryoelectron microscopy structure of the 600-kD "linkerless" construct, in which the 69-residue linker is spliced out and replaced with the tripeptide PTQ, reveals that cyclase pairs associate with all four sides of the PT octamer and exhibit fascinating quaternary structural flexibility. These results suggest that optimal substrate channeling is achieved when a cyclase domain associates with the side of the PT octamer, regardless of whether the two domains are covalently linked and regardless of whether this interaction is transient or locked in place.

Relationship between Preferential Trade Agreements and Foreign Direct Investment: Evidence from a Panel of 147 Countries

ABSTRACT This study examines the impact of preferential trade agreements (PTAs) on the inflows of foreign direct investment (FDI). Empirical results suggest that FDI gains of preferential trade are increasing with the market size of the preferential trading partners but not due to their economic and geographic closeness to the host country. It is also observed that the association between PTAs and inflows of FDI only exists for middle- and high-income countries, whereas this relationship disappeared for low-income countries. This study recommends that countries should offer various trade related benefits to overseas investors in order to attract higher inflows of capital.

Dial PTAs for Peace: The Influence of Preferential Trade Agreements on Litigation between Trading Partners

Preferential trade agreements (PTAs) are en vogue both as policy tool, as well as research subject. We do not beg to differ. In this article, inspired by the behaviour of the European Union (EU), we ask whether the proliferation of PTAs and the negotiation of mega-regionals, like the Trans-Atlantic Trade and Investment Partnership (TTIP) between the EU and the United States (US), risk undermining the WTO Dispute Settlement Mechanism (DSM), 'the crown jewel of the WTO system'. The EU is the world's biggest participant in PTAs. It is also, after the US, the most active participant to WTO disputes. Yet, in the twenty years since the creation of the WTO, it has only been involved in a tiny number of disputes with PTA partners. We find that, despite appearances to the contrary, the US has also been involved in very few WTO disputes with its PTA partners. Moreover, without assigning causal relationship to the signature of a PTA and the amount of litigation between preferential partners, we show that there is inverse correlation between the two. We find it likely therefore that the number of WTO disputes is likely to continue decreasing as WTO Members, including the EU and the US, continue signing PTAs. It remains to be seen whether the WTO system will profit or suffer from the likelihood of fewer WTO disputes.

Are Preferential Agreements Significant for the World Trade Structure? A Network Community Analysis

We assess the impact of preferential trade agreements (PTAs) on the structure of world trade by looking for communities in the world trade network (WTN), and allowing the presence of preferential trade patterns to emerge endogenously. The finding of significant communities (as defined in the topology of the networks) would imply that trading countries are organized in groups of preferential partners. We use different approaches to analyze communities in the WTN between 1962 and 2008, but all methods agree in finding no evidence of a significant partition, supporting the view that the existing PTAs are not strongly distorting the geography of trade patterns, at least at the aggregate level.

Natural Trading Partners? A Public Opinion Perspective on Preferential Trade Agreements

While global trade talks have been making very little progress in recent years, the number of preferential trade agreements (PTAs) has grown rapidly, and many of these institutions are reaching much deeper into the domestic political arena than traditional multilateral trade liberalization. Various macro-level theoretical arguments have sought to explain this trend. In this chapter, we examine public opinion with respect to key features of the "new regionalism". In particular, we are interested in what characteristics are making countries more (or less) attractive as preferential trading partners from the viewpoint of citizens (voters). We hypothesize that voters in democratic countries tend to favor PTAs with states that are geographically closer, culturally similar, of larger economic size, democratic, and have high environmental and labor rights standards. Using a conjoint experiment with a sample of U.S. respondents we find strong support for most of these arguments.

In planta validation of HK1 homodimerization and recruitment of preferential HPt downstream partners involved in poplar multistep phosphorelay systems

Multistep phosphorelays involve a phosphate transfer from sensor histidine-aspartate kinases (HKs) to response regulators (RRs), via histidine-containing phosphotransfer proteins (HPts). In Arabidopsis, some AHK receptors are organized as homodimers and able to interact with HPts (AHPs). However, there are no data available concerning the dimerization of the Arabidopsis osmosensor AHK1. Although only AHP2 is able to interact with AHK1 in yeast, validation of this interaction remains to be clarified in planta. The ability of poplar HK1 osmosensor, homologous to AHK1, to homodimerize and interact with three HPts (HPt2, 7 and 9) as preferential partners has been previously shown by yeast two-hybrid assay. However, protein interaction studies need to use complementary approaches to avoid interaction artifacts. Here, we confirmed in planta homodimerization of the cytoplasmic part of HK1 (HK1-CP) and the functional relevance of HK1-CP/HPt interactions by bimolecular fluorescence complementation assays. This work led us to validate these partnerships and to propose them as probably involved in osmosensing pathway in Populus.

Trade Policy Determinants and Trade Reform in a Developing Country: The Case of Colombia

In this paper, I empirically examine trade policy determinants and trade reform in a developing country setting by using a political economy of trade policy model to guide my estimations for Colombia between 1983 and 1998. I introduce a novel approach to estimating the extra political weights placed by the government on the well-being of producers relative to average citizens. This is under the assumption that producers are organized in terms of trade policy while the public is not. I measure the impact of sectorial characteristics on tariffs indirectly through political weights as a novel alternative to nonstructurally estimating them as determinants of protection. Accordingly, I obtain more realistic estimates as compared to the earlier literature. I also show that it is important to control for the drastic unilateral trade reform shock that affects all sectors and I test the effect of preferential trade agreements (PTAs) on tariffs in the presence of such trade liberalization. I find that protection is higher in sectors that are important exports for preferential partners which may be seen as a slowing down effect of PTAs for Colombia. The estimations account for endogeneity and omitted variable bias concerns.

Existence and significance of communities in the World Trade Web

The World Trade Web (WTW), which models the international transactions among countries, is a fundamental tool for studying the economics of trade flows, their evolution over time, and their implications for a number of phenomena, including the propagation of economic shocks among countries. In this respect, the possible existence of communities is a key point, because it would imply that countries are organized in groups of preferential partners. In this paper, we use four approaches to analyze communities in the WTW between 1962 and 2008, based, respectively, on modularity optimization, cluster analysis, stability functions, and persistence probabilities. Overall, the four methods agree in finding no evidence of significant partitions. A few weak communities emerge from the analysis, but they do not represent secluded groups of countries, as intercommunity linkages are also strong, supporting the view of a truly globalized trading system.

US International Trade and the Global Economic Crisis

World trade volume is in retreat for the first time in more than two decades and the contraction is on a scale not seen since the global recession following the second oil shock of 1979–1980. The United States (US) is at the epicenter of the crisis and is a major source of external demand for developing Asia and Pacific economies. US import and export data are examined to understand the repercussions of the crisis for international trade, particularly for export-oriented economies in East and Southeast Asia. US trade with preferential trade partners is found to be contracting significantly faster than trade with the rest of the world. Moreover, US imports that avail of preferential tariff treatment are also contracting more sharply than imports from non-preferential partners. Developing Asian non-preferential suppliers appear to be performing better in the US market than free trade agreement partners. If preferential trade is faltering and trade disputes are on the rise, the question becomes whether the multilateral trading system can ride to the rescue before protectionist forces begin to strangle world trade. The failure of bilateral free trade agreements to act as a shock absorber suggests that a new global trade deal may be the way forward. The outcome is crucial as the US will need to expand net exports to restore growth and unwind its global debt obligations.

Regional Trade Agreements and the Neo-Colonialism of the United States of America and the European Union: A Review of the Principle of Competitive Imperialism

The recent proliferation of Regional Trade Agreements (RTAs) in the last two decades raises questions about the paradigm shift from the multilateral trading system of the World Trade Organization (WTO) to bilateral and regional preferential trade arrangements. Even more questionable is the fact that the United States of America (USA) and the European Union (EU), among the other trading powers of the world, are leading the use of RTAs to the detriment and neglect of non-discriminatory trade liberalisation. It has been suggested that neo-colonialism may be the motivation for the use of RTAs by the USA and the EU as their international trade policy of choice within a broader competitive process for imperial domination of their preferential trading partners. This article reviews this suggestion in order to propose an alternative explanation for the RTA practice of the USA and the EU.

Trade Policy Determinants and Trade Reform in a Developing Country

In this paper, I start out with a standard political economy of trade policy model to guide the subsequent estimation of the determinants of trade policy in a developing country. I carefully test the model with Colombian data from 1983 to 1998 accounting for endogeneity and omitted variable bias concerns and then expand it empirically in several directions. I show that it is important to control for the impact of a drastic trade reform shock that affects all sectors and disentangle its effect from preferential trade agreements (PTAs). I find that protection is higher in sectors that are important exports for preferential partners which may be seen as a stumbling block effect of PTAs for Colombia. I also relax the assumption of fixed political weights that measure the extra importance of producers' welfare relative to consumers in the government objective. I measure the impact of sectoral characteristics on tariffs indirectly through political weights as a novel alternative to nonstructurally estimating them as determinants of protection. Accordingly, I obtain more realistic estimates for the political weights further contributing to the literature.

US INTERNATIONAL TRADE AND THE GLOBAL ECONOMIC CRISIS

The decline in world trade volume in 2009 was the worst since the Great Depression. The United States (US) spread the global recession as a major source of external demand. US import and export data are examined to understand the repercussions, particularly for developing economies divided into preferential and non-preferential trading partners. A key finding is that US trade with preferential partners contracted faster than with non-preferential partners. Case studies of autos and textiles provide insights. A new global trade deal may be the way forward as the US will have to expand net exports to restore growth.

Decision‐making Processes in Group Departures of Cattle

AbstractTo keep social cohesiveness, group‐living animals have to reach consensus decisions through recruitment processes. This implies that decision‐making depends on the behaviours and social relationships of several group members at different stages of movements. We tested these assumptions in a group of fifteen 18‐mo‐old Charolais heifers (Bos taurus) at pasture, in which two observers continuously videotaped social interactions and group departures after resting periods. These departures were preceded by a phase of preparation characterized by an increase in activity. The number of heifers participating to a movement increased with the number of group members oriented in the direction of the movement before departure. The first moving animal also recruited a higher number of mates when it had a greater number of close neighbours, the first individuals to follow being mainly its preferential partners. Coercive interactions such as pressing behaviours were observed within the 5 min preceding or following departure. After departure, the numbers of walks and restarts of the first two movers were still operative in recruiting others. The frequency of pauses of the first mover was significantly higher when it was not followed, meaning that it adjusted its behaviour to that of other group members. Decision‐making was distributed among group members, with any individual being liable to move first. The behaviour of cows and their spatial distribution before departure, at departure and after departure significantly affected the number of participants in the movement, demonstrating that decision‐making was time‐distributed in the studied cattle group.

Decision making in group departures of sheep is a continuous process

For coordinated movement, group-living individuals have to reach consensus decisions through recruitment processes. Success in recruitment can depend on the spatial distribution and behaviour of animals before and/or after departure, and on their affinitive relationships. We tested the effect of such factors on recruitment processes in a group of 19 ewe lambs, Ovis aries, at pasture. Two observers continuously videotaped the behaviours of animals from a platform located in the centre of the field. Results showed that group orientation, group vigilance and activities such as head movements, stillness and number of steps increased before departure. Using general linear modelling we found that changes in most of these variables predicted the number of participants in movements. Similarly, activity of the first mover was modified in the last 2 min preceding departure, and at departure time the location and number of close neighbours of the first mover were especially influential in recruiting conspecifics. Animals first recruited were those that were close to the first mover and also its preferential partners. The behaviours of the second and third moving individuals could further influence the recruitment process. Moreover, there were clues that individuals were able to recruit others intentionally. Our findings emphasize that decision making in a group of domestic sheep was a continuous and distributed process. Recruitment depended both on group state and on the behaviour of individuals and their social relationships.

South Korea's Marginal Intra-Industry Trade and the Choice of Preferential Partners

South Korea recently signed a free trade agreement (FTA) with Chile and is currently negotiating or studying bilateral FTAs with about 20 countries. However, some South Koreans oppose such agreements because they fear that trade liberalization would result in costly factor adjustment. Many researchers believe that intra-industry trade expansion generates smaller inter-industry factor adjustment (and therefore lower costs) compared with the costs associated with inter-industry trade expansion. This paper analyzes the extent and nature of intra-industry trade and marginal intra-industry trade in South Korea, to help predict the relative costs it might face upon opening its markets to various countries.

Grooming Circadian Rhythmicity, Progesterone Levels and Partner Preference of the Reproductive Pair of a Captive Common Marmoset (Callithrix jacchus) Family Group during Pregnancy and after Parturition

One family group of common marmosets (Callithrix jacchus) maintained in captivity under natural environmental conditions (Natal, Brazil, 05°46'S, 35°12'W) was observed by focal sampling at two non-consecutive days per week during two non-consecutive pregnancies (pregnancy 1: the last 8 fortnights before parturition; pregnancy 2: the last 5 ones) and after parturition (4 fortnights for both). The hourly percentiles of the duration of self-grooming and allogrooming interactions of the reproductive pair were submitted to Cosinor analysis for the 24-h period (p ≤ 0.05). The reproductive female's progesterone was monitored by fecal collection twice a week between 7:00 h to 9:00 h. Levels of progesterone were determined by ELISA method. During pregnancy 1, all interactions of the reproductive pair showed a 24-h statistically significant period. However, after parturition this periodicity is not present in some behaviors of the reproductive male. This animal presents the 24-h periodicity only toward to the reproductive female, the subadult son and to the newborns. Hormonal levels of the reproductive female showed isolated increases above 100 ng/g at the second and third fortnight after parturition, but did not characterize ovulation. Between pregnancy 1 and 2, the family was increased by the birth of four animals. During pregnancy 2, a statistically significant 24-h period was find only in self-grooming of the reproductive male and female, and in the interactions between the reproductive pair. Also, in the interactions of the reproductive male with only one of the juvenile son. After parturition the reproductive female ovulated at the second fortnight and became pregnant again. At this time, those interactions still have a 24-h period, except in grooming directed to the juvenile son by the reproductive male. As in the first post-partum, grooming directed to the newborns showed statistically significant 24-h period. These results suggest that the reproductive pair performs 24-h rhythmic grooming interactions only with some animals, supposed to be the preferential grooming partners. Furthermore, the temporal grooming expression in common marmosets may be affected by the reproductive condition (progesterone levels) of the reproductive female, by the care of newborn after parturition and the group size.

The Making of the Middle-Class City: Transportation Policy in São Paulo

The adaptation of urban spaces to cope with increased automobile traffic has been called the ‘building of automobile cities’. This is a vague and otherwise politically naive interpretation of these important changes in capitalist societies. Cars do not run on their own and one has to ask who is behind the wheels, and for what purposes. I argue that these spatial transformations are definite economic and political undertakings related to capitalist modernization processes, in which the middle classes, as preferential partners of ruling classes, play the most important role. In these contexts, the automobile turns out to be an essential means for the reproduction of the middle classes in their pursuit of social mobility. Therefore I argue that these large transformations should instead be seen as the ‘building of middle-class cities’.This paper is about how São Paulo was transformed into a middle-class city. In it I emphasize the period from 1960 to 1980, when the city population increased from 3.6 million to 8.5 million, and 1.6 million new automobiles were put into circulation. In this period Brazil experienced a highly dynamic capitalist modernization process, with high rates of GNP growth, under authoritarian (and often repressive) political rule. New middle-class sectors were generated, supported by the concentration of income and by their ideological commitment to the new regime. The city space was physically transformed to allow for a new pattern of circulation which was directly related to the new economic activities and the new lifestyle of these middle-class sectors, for whom the automobile became a vital means of social reproduction. The middle classes were represented, inside the state, by transportation planners who promoted the ideology of modernization. The space was then reshaped in a way which favored the circulation needs of the middle class population, in its prime role of driver, rather than the needs of the majority of the population, in their primary roles of pedestrian and captive public transportation user. Moreover, the mobility and fluidity needs of these selected middle-class sectors were pursued regardless of the safety and environmental consequences of the new circulation pattern.Similar processes can be identified in the developing world where other middle-class cities have been created. In spite of social and political differences, these processes share the objective of readapting space to ease the circulation of the social sectors which are relevant to economic accumulation and political legitimation.