906 resultados para Branch-and-Price


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The framework presents how trading in the foreign commodity futures market and the forward exchange market can affect the optimal spot positions of domestic commodity producers and traders. It generalizes the models of Kawai and Zilcha (1986) and Kofman and Viaene (1991) to allow both intermediate and final commodities to be traded in the international and futures markets, and the exporters/importers to face production shock, domestic factor costs and a random price. Applying mean-variance expected utility, we find that a rise in the expected exchange rate can raise both supply and demand for commodities and reduce domestic prices if the exchange rate elasticity of supply is greater than that of demand. Whether higher volatilities of exchange rate and foreign futures price can reduce the optimal spot position of domestic traders depends on the correlation between the exchange rate and the foreign futures price. Even though the forward exchange market is unbiased, and there is no correlation between commodity prices and exchange rates, the exchange rate can still affect domestic trading and prices through offshore hedging and international trade if the traders are interested in their profit in domestic currency. It illustrates how the world prices and foreign futures prices of commodities and their volatility can be transmitted to the domestic market as well as the dynamic relationship between intermediate and final goods prices. The equilibrium prices depends on trader behaviour i.e. who trades or does not trade in the foreign commodity futures and domestic forward currency markets. The empirical result applying a two-stage-least-squares approach to Thai rice and rubber prices supports the theoretical result.

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Cryptic exons or pseudoexons are typically activated by point mutations that create GT or AG dinucleotides of new 5' or 3' splice sites in introns, often in repetitive elements. Here we describe two cases of tetrahydrobiopterin deficiency caused by mutations improving the branch point sequence and polypyrimidine tracts of repeat-containing pseudoexons in the PTS gene. In the first case, we demonstrate a novel pathway of antisense Alu exonization, resulting from an intronic deletion that removed the poly(T)-tail of antisense AluSq. The deletion brought a favorable branch point sequence within proximity of the pseudoexon 3' splice site and removed an upstream AG dinucleotide required for the 3' splice site repression on normal alleles. New Alu exons can thus arise in the absence of poly(T)-tails that facilitated inclusion of most transposed elements in mRNAs by serving as polypyrimidine tracts, highlighting extraordinary flexibility of Alu repeats in shaping intron-exon structure. In the other case, a PTS pseudoexon was activated by an A>T substitution 9 nt upstream of its 3' splice site in a LINE-2 sequence, providing the first example of a disease-causing exonization of the most ancient interspersed repeat. These observations expand the spectrum of mutational mechanisms that introduce repetitive sequences in mature transcripts and illustrate the importance of intronic mutations in alternative splicing and phenotypic variability of hereditary disorders.

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We examine the impact of real oil price shocks on labor market flows in the U.S. We first use smooth transition regression (STR) models to investigate to what extent oil prices can be considered as a driving force of labor market fluctuations. Then we develop and calibrate a modified version of Pissarides' (2000) model with energy costs, which we simulate in response to shocks mimicking the behavior of the actual oil price shocks. We find that (i) these shocks are an important driving force of job market flows; (ii) the job finding probability is the main transmission mechanism of such shocks; and (iii) they bring a new amplification mechanism for the volatility and should thus be seen as complementary of labor productivity shocks. Overall we conclude that shocks in oil prices cannot be neglected in explaining cyclical labor adjustments in the U.S.

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This paper computes and compares alternative quality-adjusted price indexes for new cars in Spain in the period 1990-2000. The proposed hedonic approach simultaneously controls for time-invariant unobserved product e¤ects and time-variant unobserved quality changes, that are assumed to be captured by model age effects. The results show that the non-adjusted price index largely overstates the increase in the cost of living induced by changes in car prices and that previous evidence for this market have not measured the real extent of that bias, probably due to the omission of controls for unobservables. It is also shown that omitting age effects can also lead to misleading conclusions. The estimated price indexes give also some insights on what could have been the determinants of price evolution in the Spanish car market.

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This paper computes and compares alternative quality-adjusted price indexes for new cars in Spain in the period 1990-2000. The proposed hedonic approach simultaneously controls for time-invariant unobserved product effects and time-variant unobserved quality changes, that are assumed to be captured by model age effects. The results show that the non-adjusted price index largely overstates the increase in the cost of living induced by changes in car prices and that previous evidence for this market have not measured the real extent of that bias, probably due to the omission of controls for unobservables. It is also shown that omitting age effects can also lead to misleading conclusions. The estimated price indexes give also some insights on what could have been the determinants of price evolution in the Spanish car market. JEL classi…fication numbers: C43, E31, L11, L13, Keywords: Hedonic price indexes, Spanish car market, car prices, CPI, Cost of living

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In a Walrasian labor market, the labor income share is constant under the assumptions of a Cobb-Douglas production function and perfect competition. Given the observed decline of the labor share in recent decades, this paper relaxes these assumptions, proposes a time-series calculation of the aggregate price mark-up reflecting the degree of imperfect competition in the product market, and provides estimates of the elasticity of substitution under such product market imperfections. We focus on Spain and the U.S. and show that the elasticity of substitution is above one in Spain and below one in the U.S. We also show that the price markup drives the elasticity of substitution away from one, upwards in Spain, downwards in the U.S. These results are used to explain the declining path of the labor income share, common to both economies, and their contrasted patterns in terms of capital deepening.

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The Minister for Health and Children has requested that an independent review be carried out of the circumstances surrounding the employment of a UK based Consultant Psychiatrist, Dr John Harding-Price, to a locum psychiatrist position with the South Eastern Health Board (SEHB) while he was suspended by the General Medical Council (GMC) in the United Kingdom and consequently the subject of legal proceedings by the Medical Council in Ireland. The Consultant was continuously registered with the Medical Council since 1968. Download the document here

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Does Weber's notion of salvation goods, along with the connected one of the religious market, apply to the modern history of yoga? The case study chosen here (the yoga of Pattabhi Jois) clearly shows that these notions highlight many aspects of the expansion of yoga into a global market product. However, the notion of salvation goods resists the new hermeneutical situation of encounter and has to be adapted to the present situation of religious "patchwork". The notion of religious market lacks depth to describe the various understandings and appropriations of yoga in precise historical situations. Other aspects of the current global status of yoga may be highlighted by applying the concept of pilgrimage. La notion de bien de salut que nous lègue Max Weber et la notion de marché religieux qui en découle peuvent-elles s'appliquer à l'histoire moderne du yoga? L'étude de cas que nous consacrons au yoga de Pattabhi Jois montre que ces notions éclairent bien certains aspects de l'expansion du yoga en tant que produit d'un marché globalisé. Cependant la notion de bien de salut résiste à une réflexion de type herméneutique sur les processus de rencontres et doit être adaptée à la situation contemporaine, ou` les religions se présentent comme des ensembles composites. La notion de marché religieux ne permet pas d'expliquer les diverses compréhensions et appropriations du yoga dans des situations historiques précises. D'autres aspects de la situation du yoga sont mieux explicités si on prend le concept de pèlerinage comme point de référence.

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Landscape is an example of a non-market good where no metrics exist to measure its quality. The paper proposes an original methodology to nevertheless estimate scope variables in those circumstances, allowing then to better test if people's willingnesstopay for such good is sensitive to the scope. The methodology is based on techniques developed in the context of multicriteria decision analysis. It is applied to assess the quality of the landscape of several Swiss alpine resorts. This assessment is then used as an explanatory variable in a hedonic price function to explain the rent of apartments and to derive an implicit price of the landscape quality.

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OBJECTIVES: The aim of this study was to evaluate new electrocardiographic (ECG) criteria for discriminating between incomplete right bundle branch block (RBBB) and the Brugada types 2 and 3 ECG patterns. BACKGROUND: Brugada syndrome can manifest as either type 2 or type 3 pattern. The latter should be distinguished from incomplete RBBB, present in 3% of the population. METHODS: Thirty-eight patients with either type 2 or type 3 Brugada pattern that were referred for an antiarrhythmic drug challenge (AAD) were included. Before AAD, 2 angles were measured from ECG leads V(1) and/or V(2) showing incomplete RBBB: 1) α, the angle between a vertical line and the downslope of the r'-wave, and 2) β, the angle between the upslope of the S-wave and the downslope of the r'-wave. Baseline angle values, alone or combined with QRS duration, were compared between patients with negative and positive results on AAD. Receiver-operating characteristic curves were constructed to identify optimal discriminative cutoff values. RESULTS: The mean β angle was significantly smaller in the 14 patients with negative results on AAD compared to the 24 patients with positive results on AAD (36 ± 20° vs. 62 ± 20°, p < 0.01). Its optimal cutoff value was 58°, which yielded a positive predictive value of 73% and a negative predictive value of 87% for conversion to type 1 pattern on AAD; α was slightly less sensitive and specific compared with β. When the angles were combined with QRS duration, it tended to improve discrimination. CONCLUSIONS: In patients with suspected Brugada syndrome, simple ECG criteria can enable discrimination between incomplete RBBB and types 2 and 3 Brugada patterns.

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Fanconi anemia (FA) is a genetically heterogeneous cancer-prone disorder associated with chromosomal instability and cellular hypersensitivity to DNA crosslinking agents. The FA pathway is suspected to play a crucial role in the cellular response to DNA replication stress. At a molecular level, however, the function of most of the FA proteins is unknown. FANCM displays DNA-dependent ATPase activity and promotes the dissociation of DNA triplexes, but the physiological significance of this activity remains elusive. Here we show that purified FANCM binds to Holliday junctions and replication forks with high specificity and promotes migration of their junction point in an ATPase-dependent manner. Furthermore, we provide evidence that FANCM can dissociate large recombination intermediates, via branch migration of Holliday junctions through 2.6 kb of DNA. Our data suggest a direct role for FANCM in DNA processing, consistent with the current view that FA proteins coordinate DNA repair at stalled replication forks.