Credibility and Monetary Policy

A highly credible monetary policy helps to reduce the degree of uncertainty that can surround the objectives of such policy. When the monetary policy pursued by the central bank is credible, the expectations of the public are focused on a target. If the public believes that the Bank will act to bring inflation back to the target, then its expectations will not react so strongly to fluctuating price trends. In turn, fluctuations in inflation, interest rates, output, and employment should be less pronounced than in the absence of such credibility. The adoption of inflation control as a monetary policy objective by some countries has led central banks to take steps to enhance the credibility of monetary policy. For the Bank of Canada, these include the publication of our Monetary Policy Report each May and November, with formal updates each February and August the initiation of communications activities across the country the use of the overnight interest rate as a short-term operating target the issuing of a press release each time the Bank changes its key rates. To date, most of the studies on this topic have concluded that success in keeping inflation within a target range has helped to increase the credibility of Canadian monetary policy. These surveys suggest that expected inflation, which stood at about 5 per cent in 1990, declined to around 2 per cent by 1999 (Chart 1, page 15). Indeed, according to these surveys, for the entire period during which the Bank has had a target range for inflation, expected inflation rates have remained within that range. Inflation expectations have also reacted very little to changes in the total CPI, suggesting that the targets have helped to focus expectations on the target rate and have thus enhanced the credibility of monetary policy (Chart 2, page 16). One particular study shows that the life of collective wage agreements in Canada has been increasing and that the number of such agreements containing cost-of-living adjustment (COLA) clauses has steadily declined. The authors of this study suggest that this may reflect the greater credibility of Canadian monetary policy (Table 1, page 16). The proportion of mortgages with five-year terms is now higher than it was in the mid-1980s, and many financial institutions have been offering 7-to 10-year mortgages. This also suggests that inflation targets have gained credibility.

An Optimized Monetary Policy Rule for ToTEM

The authors propose a monetary policy rule for the Terms-of-Trade Economic Model (ToTEM), the Bank of Canada's new projection and policy-analysis model for the Canadian economy. They consider simple instrument rules such as Taylor-type and inflation-forecast-based rules. The proposed rule minimizes a loss function that reflects the assumed preferences of the monetary authority over inflation and output, as well as over the variability of its instrument. The authors also investigate how robust the proposed rule is with respect to a particular realization of shocks that differs from the historical distribution used to find the optimized rule.Economic models; Monetary policy framework; Transmission of monetary policy

Multilocus haplotyping by parallel sequencing to decipher the interspecific mosaic genome structure of cultivated citrus

The most important economic Citrus species originated from natural interspecific hybridization between four ancestral taxa (C. reticulata, C. maxima, C. medica and C. micrantha) with limited further interspecific recombination due to apomixis and vegetative propagation. Such reticulate evolution coupled with vegetative propagation results in genomes that are mosaics of large chromosome fragments of the basic taxa, in frequent interspecific heterozygosity. Breeding of these species is hampered by their complex heterozygous genomic structures. Haplotyping of multiple gene fragments along the genome should be a powerful approach to resolve the evolutionary history of the gene pools, to reveal the admixture genomic structure of current species and to develop innovative breeding schemes. We have analysed the efficiency of parallel sequencing with 454 methodology to decipher the hybrid structure of modern citrus species and cultivars along chromosome 2. Four hundred fifty four amplicon libraries were established with the fluidigm array system for 48 genotypes and 16 gene fragments of chromosome 2. Haplotypes were established from the reads of each accession and phylogenetic analyses were performed from the haplotypic data of each gene fragment. The length of 454 reads and the level of differentiation between the ancestral taxa of modern citrus allowed efficient haplotype phylogenetic assignations for 12 of the 16 gene fragments. The analysis of the mixed genomic structure of modern species and cultivars (i) revealed C. maxima introgressions in modern mandarins; (ii) was consistent with previous hypothesis regarding the origin of secondary species; and (iii) provided a new picture of the evolution of chromosome 2. Perspectives to rebuild the main secondary species from the basic taxa are discussed. (Résumé d'auteur

Les évaluations de coûts en santé sont-elles transférables ?

Cette étude de la transférabilité des résultats des évaluations de coûts en santé repose sur l'analyse en composantes principales et les distances euclidiennes. Elle permet de montrer si les résultats sont faiblement, moyennement ou largement transférables. Le recours à ces deux méthodes validées pour mesurer la transférabilité des résultats constitue, de ce point de vue, une démarche originale. Son opérationnalité est également démontrée dans le cadre d'un traitement innovant, la radiothérapie par ions carbone. Une analyse « globale » témoigne, par exemple, d'une forte distance entre l'Italie et les Pays-Bas. Tous facteurs confondus, les résultats sont donc faiblement transférables entre ces deux pays. Une analyse plus fine montre que les distances sont maximales et donc la transférabilité minimale pour les coûts des bâtiments et les paramètres organisationnels.cost ; economic assessment ; health ; oncology ; transferability

Analysis of genetic diversity in Tunisian citrus rootstocks

Breeding and selection of new citrus rootstocks are nowadays of the utmost importance in the Mediterranean Basin because the citrus industry faces increasing biotic and abiotic constraints. In Tunisia, citrus contributes significantly to the national economy, and its extension is favored by natural conditions and economic considerations. Sour orange, the most widespread traditional rootstock of the Mediterranean area, is also the main one in Tunisia. In addition to sour orange, other citrus rootstocks well adapted to local environmental conditions are traditionally used and should be important genetic resources for breeding. Prior to initiation of any breeding program, the exploration of Tunisian citrus rootstock diversity was a priority. Two hundred and one local accessions belonging to four facultative apomictic species (Citrus aurantium, sour orange; Citrus sinensis, sweet orange; Citrus limon, lemon; and Citrus aurantifolia, lime) were collected and genotyped using 20 nuclear SSR markers and four InDel mitochondrial markers. Sixteen distinct Multi-locus genotypes (MLGs) were identified and compared to references from French and Spanish collections. The differentiation of the four varietal groups was well-marked. Each group displayed a relatively high allelic diversity, primarily due to very high heterozygosity. The Tunisian citrus rootstock genetic diversity is predominantly due to high heterozygosity and differentiation between the four varietal groups. The phenotypic diversity within the varietal groups has resulted from multiple introductions, somatic mutations and rare sexual recombination events. This diversity study enabled the identification of a core sample of accessions for further physiological and agronomic evaluations. These core accessions will be integrated into citrus rootstock breeding programs for the Mediterranean Basin. (Résumé d'auteur

Extrakorporale hydrostatische Hochdruckbehandlung als neues Verfahren zur Desinfektion infizierter Knochenpräparate

Background: Allogeneic bone transplantation is at risk of infection, and established disinfection methods typically compromise bone quality. High hydrostatic pressure (HHP) is well established for disinfection in food technology, and also it does protect biomechanical and biological properties of bone. This study is the first investigation of HHP regarding disinfection of bone biopsies. Materials and methods: Bone biopsies of 34 patients with chronic infections were subjected to HHP and assessed for persisting bacterial growth. In series 1, bone biopsies were proceeded directly to HHP (10 min; maximal pressure P-max 600 MPa). In series 2, HHP was applied after 5-day incubation in growth media (10 min or 2 x 30 min; P-max 600 MPa). Furthermore, HHP-induced changes of bacterial morphology on artificially infected bone samples were evaluated by scanning electron microscopy (SEM). Results: For series 1, 71% of the bone samples were sterilised by HHP (n = 17), compared to 38% of the untreated control samples, which were obtained during the same surgery (n = 8). For series 2, after prior incubation, HHP disinfected 7% of the bone specimens (n = 55), all control samples showed bacterial growth (n = 33). Destruction of cell wall integrity of Gram-negative strains was observed by SEM. Conclusion: The effectiveness of HHP for bone disinfection should be improved by optimising treatment parameters. Infections with barosensitive Gram-negative bacteria or yeast might represent possible clinical indications

Sequencing of diverse mandarin, pummelo and orange genomes reveals complex history of admixture during citrus domestication

Cultivated citrus are selections from, or hybrids of, wild progenitor species whose identities and contributions to citrus domestication remain controversial. Here we sequence and compare citrus genomes-a high-quality reference haploid clementine genome and mandarin, pummelo, sweet-orange and sour-orange genomes-and show that cultivated types derive from two progenitor species. Although cultivated pummelos represent selections from one progenitor species, Citrus maxima, cultivated mandarins are introgressions of C. maxima into the ancestral mandarin species Citrus reticulata. The most widely cultivated citrus, sweet orange, is the offspring of previously admixed individuals, but sour orange is an F1 hybrid of pure C. maxima and C. reticulata parents, thus implying that wild mandarins were part of the early breeding germplasm. A Chinese wild 'mandarin' diverges substantially from C. reticulata, thus suggesting the possibility of other unrecognized wild citrus species. Understanding citrus phylogeny through genome analysis clarifies taxonomic relationships and facilitates sequence-directed genetic improvement. (Résumé d'auteur

Assessment of the genetic diversity of the Tunisian citrus rootstock germplasm

<p>Abstract</p> <p>Background</p> <p>Citrus represents a substantial income for farmers in the Mediterranean Basin. However, the Mediterranean citrus industry faces increasing biotic and abiotic constraints. Therefore the breeding and selection of new rootstocks are now of the utmost importance. In Tunisia, in addition to sour orange, the most widespread traditional rootstock of the Mediterranean area, other citrus rootstocks and well adapted to local environmental conditions, are traditionally used and should be important genetic resources for breeding. To characterize the diversity of Tunisian citrus rootstocks, two hundred and one local accessions belonging to four facultative apomictic species (<it>C. aurantium</it>, sour orange; <it>C. sinensis</it>, orange; <it>C. limon</it>, lemon; and <it>C. aurantifolia</it>, lime) were collected and genotyped using 20 nuclear SSR markers and four indel mitochondrial markers. Multi-locus genotypes (MLGs) were compared to references from French and Spanish collections.</p> <p>Results</p> <p>The differentiation of the four varietal groups was well-marked. The groups displayed a relatively high allelic diversity, primarily due to very high heterozygosity. Sixteen distinct MLGs were identified. Ten of these were noted in sour oranges. However, the majority of the analysed sour orange accessions corresponded with only two MLGs, differentiated by a single allele, likely due to a mutation. The most frequent MLG is shared with the reference sour oranges. No polymorphism was found within the sweet orange group. Two MLGs, differentiated by a single locus, were noted in lemon. The predominant MLG was shared with the reference lemons. Limes were represented by three genotypes. Two corresponded to the 'Mexican lime' and 'limonette de Marrakech' references. The MLG of 'Chiiri' lime was unique.</p> <p>Conclusions</p> <p>The Tunisian citrus rootstock genetic diversity is predominantly due to high heterozygosity and differentiation between the four varietal groups. The phenotypic diversity within the varietal groups has resulted from multiple introductions, somatic mutations and rare sexual recombination events. Finally, this diversity study enabled the identification of a core sample of accessions for further physiological and agronomical evaluations. These core accessions will be integrated into citrus rootstock breeding programs for the Mediterranean Basin.</p