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With soybean [Glycine max (L.) Merr.] seed cost increasing in Alberta, understanding economic optimum plant density (EOPD) could help growers save on input expenses. A study was conducted at two irrigated locations in southern Alberta (Bow Island and Lethbridge), in three growing seasons (2014–2016), using two maturity group (MG) 00 soybean genotypes, two row spacings (RS; narrow, 17.5 cm; wide, 35 cm), and three seeding densities (SD; 30, 50 and 80 seeds·m−2). Exponential plant density–yield relationships were used to estimate EOPD. The earlier MG 00.4 genotype compensated yield at lower plant density (39 vs. 43 plants·m−2) and emergence (74% vs. 80%) than the later MG 00.8 genotype. The EOPD gaps between environments, genotypes, and RS were minimal (from 1–3 plants·m−2), resulting in only 1.3%–2.0% differences in grain yield (37–56 kg·ha−1), and gross revenue at EOPD ($16–24·ha−1). The overall EOPD estimate was 46 plants·m−2, regardless of environment, genotype or RS. The study highlighted the difference between agronomic production and profit maximization in choosing an optimum plant density, and the need to establish a seeding density calculator for irrigated soybean in southern Alberta.

An irrigation study in southern Alberta compared spring-banded nitrogen (N) to spring-banded N plus fertigation at three plant growth stages for spring wheat (Triticum aestivum L.) and canola (Brassica napus L.). Yield and quality impacts were quantified when N fertigation was applied to (i) wheat at the early tillering, flag leaf, and anthesis stages and (ii) canola at the four-leaf rosette, bolting, and early flowering stages. For both crops, fertigation could replace some spring-banded N without an effect on yield. However, the results revealed that for canola grown with a large amount of N, applying it all in the spring often generated higher yields than if an equivalent amount of N was delivered at later stages by fertigation. Canola oil concentration declined marginally (about 1%) from no applied N to the high rate of applied N. The application of more than 60 kg N ha−1 and delayed application each increased wheat protein content. Comparing revenues to costs, fertigation did not improve profit margins for canola growers. When growers applied 90 or 120 kg N ha−1 in the spring, fertigation was financially counter-productive. In contrast, the main benefit to wheat growers from fertigation was higher grain protein, especially with N applied at later growth stages. When protein premiums increase during the growing season, fertigation would facilitate growers to obtain higher net returns than they would otherwise.

International audience; We analyzed 21 rockfalls that occurred in limestone cliffs of the Chartreuse Massif (French Alps). These rockfalls were detected both by Terrestrial Laser Scanning or photogrammetry and by a local seismological network. The combination of these methods allowed us to study relations between rockfall properties (location of detachment and impacts areas, volume, geometry, propagation) and the induced seismic signal. We observed events with different propagation modes (sliding, mass flow, free-fall) that could be determined from Digital Elevation Models. We focused on events that experienced a free-fall after their detachment. We analyzed the first parts of the seismic signals corresponding to the detachment phase and to the first impact. The detachment phase has a smaller amplitude than the impact phase, and its amplitude and duration increasewith rockfall volume. By measuring the time delay between the detachment phase and the first impact, we can estimate the free-fall height. We found a relation Es=aEpbbetween the potential energy of a rockfall Ep and the seismic energy Esgenerated during the first impact, with parameters a=10-8and b=1.55 and with a correlation coefficient R²=0.98. We can thus estimate both the potential energy of a block and its free-fall height from the seismic signals. By combining these results, we obtain an accurate estimate of the rockfall volume. This relation was then tested on different geological settings and for larger volumes using Yosemite and Mount Granier rockfalls. We also compared our results with a data set of controlled releases of single blocks (Hibert et al., 2017) in order to investigate smaller volumes.

We assessed the extent to which summer fallow in the Dark Brown soil zone is likely to return as a response to net return (NR) risk. An economic model was used to identify, delineate, and quantify ...

Background Understanding the effects of resistance QTL on pathogen development cycle is an important issue for the creation of QTL combination strategies to durably increase disease resistance in plants. The oomycete pathogen Aphanomyces euteiches, causing root rot disease, is one of the major factors limiting the pea crop in the main producing countries. No commercial resistant varieties are currently available in Europe. Resistance alleles at seven main QTL were recently identified and introgressed into pea agronomic lines, resulting in the creation of Near Isogenic Lines (NILs) at the QTL. This study aimed to determine the effect of main A. euteiches resistance QTL in NILs on different steps of the pathogen life cycle. Results NILs carrying resistance alleles at main QTL in susceptible genetic backgrounds were evaluated in a destructive test under controlled conditions. The development of root rot disease severity and pathogen DNA levels in the roots was measured during ten days after inoculation. Significant effects of several resistance alleles at the two major QTL Ae-Ps7.6 and Ae-Ps4.5 were observed on symptom appearance and root colonization by A. euteiches. Some resistance alleles at three other minor-effect QTL (Ae-Ps2.2, Ae-Ps3.1 and Ae-Ps5.1) significantly decreased root colonization. The combination of resistance alleles at two or three QTL including the major QTL Ae-Ps7.6 (Ae-Ps5.1/Ae-Ps7.6 or Ae-Ps2.2/Ae-Ps3.1/Ae-Ps7.6) had an increased effect on delaying symptom appearance and/or slowing down root colonization by A. euteiches and on plant resistance levels, compared to the effects of individual or no resistance alleles. Conclusions This study demonstrated the effects of single or multiple resistance QTL on delaying symptom appearance and/or slowing down colonization by A. euteiches in pea roots, using original plant material and a precise pathogen quantification method. Our findings suggest that single resistance QTL can act on multiple or specific steps of the disease development cycle and that their actions could be pyramided to increase partial resistance in future pea varieties. Further studies are needed to investigate QTL effects on different steps of the pathogen life cycle, as well as the efficiency and durability of pyramiding strategies using QTL which appear to act on the same stage of the pathogen cycle. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0822-4) contains supplementary material, which is available to authorized users.

Effects of NILs carrying single or combined resistance on variables of the Aphanomyces root rot development cycle. A-C/ Single QTL NIL experiment #1; D/ Combined and single QTL NIL experiment #4; E/ Single QTL NIL experiment #2. The first graph represents the evolution of the probability of symptom appearance for seven days after inoculation, for each line. It corresponds to the percentage of plants with symptoms per block for each scoring day. The second graph shows for each line the root colonization speed, corresponding to the slope of the curve of pathogen DNA amounts per block, until 10 days after inoculation, from 104 DNA copies detected. Pathogen DNA data was used from one biological replicate at the fourth day in experiments #1 and #2 and the seventh day in experiment #4. In the third graph, the AUDPC was calculated from the pathogen DNA quantification data over the ten days after inoculation. Bars represent standard errors. Attribution of each line to LSMeans group(s) is indicated by letter(s), according to the Tukey test (P

DS scores probability in each NIL set at each scoring day. A Experiments #1 and #2; B Experiments #3 and #4. The colors in each bar represent the probabilities of scores “0” (healthy plant) to “5” (dead plant), according to the DS rating scale used [25]. At two and three days after inoculation, no DS scores probability could be calculated from the CLMM model because some lines did not have symptoms. (PDF 1351 kb)

We analyze the implications of switching from existing seniority-based allocations to proportional water sharing policies in times of water shortage in the Bow River Sub-Basin in Southern Alberta. In particular, we simulate three variations of the proportional water sharing concept: (1) irrigation districts’ permissible diversions are reduced in proportion to each district's licenced allocations; (2) the diversions are reduced in proportion with each district's past five-year average diversions; and (3) the diversions are reduced proportionately with each district's diversion in a single prior year. Compared to the seniority-based allocations, all three alternative policies produce unambiguously better results. With trades, the prospect of overall economic gain improves further. However, the distribution of potential monetary gains varies across scenarios.

In this study, the gross margins (above variable costs) are estimated in Canadian dollars of 16 important irrigated crops in Southern Alberta over the years 2004 to 2008. The residual method is then used to estimate the total incremental gross margins (gross margins from irrigated crops minus estimated gross margins from dryland crops had irrigation not been available) of using water to irrigate agricultural crops in four sub-basins in Southern Alberta over those years. The annual incremental gross margins averaged $244 million (in 2008 Canadian dollars) per year and varied from a low of $218 million in 2007 to a high of $271 million in 2005. On a per hectare planted basis, the annual average gross margin from irrigated cropping was $590 and the incremental gross margin was $495. The average annual gross margin and incremental gross margin per 1000 m3 were $225 and $191, respectively.

The Boundary Waters Treaty of 1909 set out the terms and conditions by which citizens in Canada and the United States would be permitted to access and use trans-national surface water resources. In 2003, the Governor of Montana claimed that Montanans were not receiving their collective entitlement of the boundary waters that flowed into Alberta and requested the International Joint Commission (IJC) to investigate. After more than eight years of study, meetings, task forces and negotiations, the IJC has successfully cooled emotions but a definitive solution to the dispute has not been found. Although water users in Alberta have been receiving more water than those in Montana, it has been determined that users in both countries have been receiving less water than their legal entitlements. This result has been due more to differences in diversion, conveyance and storage infrastructure on each side of the border than to any inherent unfairness in the treaty itself.

A customized version of the deterministic Food and Agricultural Policy Research Institute (FAPRI) modeling system was used to assess the impacts of two alternative scenarios: (1) an increase in Canadian ethanol demand to 10% of domestic liquid fuel consumption by 2011 met through increased ethanol imports, and (2) the same increase in Canadian ethanol demand met only through increased domestic supply. The results reveal import barriers injure Canadian consumers by limiting their access to supplies offered for sale at lower prices by more efficient producers, particularly those located in subtropical regions. With freer trade, the domestic ethanol price would fall while the world price would rise due to the higher demand for ethanol in Canada. The results also show that import restrictions directly undermine the effectiveness and increase the costliness of a higher consumption mandate in Canada. The relatively less expensive ethanol is for the final consumer, the more likely they will use it as fuel over available alternatives. The implication is that restricting imports of ethanol is counterproductive to the policy objective of increasing domestic ethanol consumption. Nous avons utilise une version adaptee du systeme de modelisation deterministe du Food and Agricultural Policy Research Institute (FAPRI) pour evaluer les repercussions de deux scenarios possibles : 1. une hausse de la demande canadienne d’ethanol equivalant a dix pour cent de la consommation interieure de combustible liquide d’ici 2011 grâce a l’augmentation des importations d’ethanol; 2. la meme hausse grâce, cette fois, a l’augmentation des approvisionnements interieurs seulement. Nos resultats ont indique que les obstacles a l’importation lesent les consommateurs canadiens en limitant leur acces a des approvisionnements offerts a faibles prix par des producteurs plus efficaces, en particulier ceux des regions subtropicales. En presence d’une liberalisation accrue des echanges, le prix interieur de l’ethanol reculerait tandis que le prix mondial augmenterait en raison de l’accroissement de la demande d’ethanol au Canada. Nos resultats ont egalement indique que les restrictions a l’importation reduisent directement l’efficacite et augmentent la cherte du mandat visant a stimuler la consommation d’ethanol au Canada. Plus le prix de l’ethanol sera abordable pour le consommateur final, plus ce dernier sera enclin a l’utiliser comme combustible par rapport aux autres sources disponibles. Imposer des restrictions a l’importation d’ethanol fait plus de tort que de bien a l’objectif de la politique qui vise a accroitre la consommation interieure d’ethanol.

La creation de cette activite n’etait pas recente puisqu’elle datait de 1941, et ceci a la demande de la Chambre syndicale des constructeurs d’appareils d’electroradiologie. Cette section specialisee avait pour objet la verification de la conformite auxnormesdes appareils generateurs de rayonsXainsi quedes appareils d’electricite medicale : appareils de radiothermie a haute frequence, generateurs d’ultrasons, electrocardiographes, etc.

The objectives of this paper are (a) to estimate the overall losses to the beef industry in Canada from BSE by identifying and estimating the increased costs and reduced revenues to the industry from May 2003 to September 2007; and (b) to assess the extent to which compensation paid by federal and provincial governments to producers of cattle and beef products covered these losses. The analysis suggests that in aggregate, the industry in Canada was fully indemnified through federal and provincial assistance programs, but the gains or losses to various sectors within the beef industry cannot be identified.

This review provides an overview of consumer and government responses to bovine serum encephalopathy (BSE) and draws lessons for industry stakeholders. The approaches taken around the world to contain the risk of BSE where it was discovered reveal important patterns, differences and difficulties. Important lessons are drawn in three areas: (1) the paramount position of consumers of beef with respect to production, processing and regulatory activities; (2) the importance of clearly communicating relative risks of infection to the public; and (3) the critical role of improved international trade rules to mitigate financial impacts of animal disease outbreaks.

The days following the discovery of BSE in Canada were characterized by considerable uncertainty for both policy makers and industry stakeholders. This paper develops eight criteria for economic systems models that would provide information on the impacts of border closures and the effects of programs designed to alleviate some of the financial strain on industry stakeholders. The eight criteria provide a framework to evaluate two economic models used extensively by policy makers in Canada to provide policy guidance in addition to a survey of published economics literature related to the Canadian beef industry prior to the discovery of the BSE case in May 2003. The results suggest a need to improve the combination of knowledge and modeling skills and techniques before another tragedy strikes the agricultural industry in Canada. Les jours qui ont suivi la decouverte d'un cas d'ESB au Canada ont seme beaucoup d'incertitude chez les decideurs et les acteurs de l'industrie. Dans la presente etude, nous avons elabore huit criteres pour des modeles de systemes economiques qui fourniraient de l'information sur les repercussions de la fermeture des frontieres et sur les effets des programmes visant a attenuer une partie des contraintes financieres auxquelles sont confrontes les acteurs de l'industrie. Les huit criteres offrent un cadre pour evaluer deux modeles economiques que les decideurs au Canada utilisent frequemment pour determiner une orientation politique, en plus d'un tour d'horizon de la litterature economique sur l'industrie bovine au Canada avant la decouverte du premier cas d'ESB en mai 2003. Les resultats ont montre la necessite d'ameliorer la combinaison connaissances, competences et techniques de modelisation avant qu'une autre tragedie ne frappe l'industrie agricole canadienne.

International audience; Marker-assisted backcrossing was used to generate pea NILs carrying individual or combined resistance alleles at main Aphanomyces resistance QTL. The effects of several QTL were successfully validated depending on genetic backgrounds. Quantitative trait loci (QTL) validation is an important and often overlooked step before subsequent research in QTL cloning or marker-assisted breeding for disease resistance in plants. Validation of QTL controlling partial resistance to Aphanomyces root rot, one of the most damaging diseases of pea worldwide, is of major interest for the future development of resistant varieties. The aim of this study was to validate, in different genetic backgrounds, the effects of various resistance alleles at seven main resistance QTL recently identified. Five backcross-assisted selection programs were developed. In each, resistance alleles at one to three of the seven main Aphanomyces resistance QTL were transferred into three genetic backgrounds, including two agronomically important spring (Eden) and winter (Isard) pea cultivars. The subsequent near-isogenic lines (NILs) were evaluated for resistance to two reference strains of the main A. euteiches pathotypes under controlled conditions. The NILs carrying resistance alleles at the major-effect QTL Ae-Ps4.5 and Ae-Ps7.6, either individually or in combination with resistance alleles at other QTL, showed significantly reduced disease severity compared to NILs without resistance alleles. Resistance alleles at some minor-effect QTL, especially Ae-Ps2.2 and Ae-Ps5.1, were also validated for their individual or combined effects on resistance. QTL × genetic background interactions were observed, mainly for QTL Ae-Ps7.6, the effect of which increased in the winter cultivar Isard. The pea NILs are a novel and valuable resource for further understanding the mechanisms underlying QTL and their integration in breeding programs.

Un nouveau dosimetre passif base sur la technologie OSL vient d’etre introduit sur le marche francais. Dans cet article sont decrits : la technologie et le materiau sur lequel s’appuie ce nouveau detecteur, le dosimetre lui-meme.

Transcription factor IIH (TFIIH) is a multisubunit complex required for transcription and for DNA nucleotide excision repair. TFIIH possesses three enzymatic activities: (i) an ATP-dependent DNA helicase, (ii) a DNA-dependent ATPase, and (iii) a kinase with specificity for the carboxyl-terminal domain of RNA polymerase II. The kinase activity was recently identified as the cdk (cyclin-dependent kinase) activating kinase, CAK, composed of cdk7, cyclin H, and MAT-1. Here we report the isolation and characterization of three distinct CAK-containing complexes from HeLa nuclear extracts: CAK, a novel CAK-ERCC2 complex, and TFIIH. CAK-ERCC2 can efficiently associate with core-TFIIH to reconstitute holo-TFIIH transcription activity. We present evidence proposing a critical role for ERCC2 in mediating the association of CAK with core TFIIH subunits.

Introduction La maladie de Crohn (MC) est une maladie inflammatoire chronique du tube digestif caracterisee par un infiltrat inflammatoire segmentaire et transmural, avec de facon inconstante une reaction granulomateuse epithelioide a cellules geantes, sans necrose caseeuse. Des poussees peuvent survenir au cours de la grossesse, bien que la maladie reste le plus souvent quiescente [1] . La myasthenie auto-immune (MAI) peut etre associee a une ou plusieurs autres affections auto-immunes, en particulier des dysthyroidies. L’association a une MC a rarement ete rapportee dans la litterature [2] . Observation Nous rapportons le cas d’une patiente âgee de 30 ans enceinte a 16 semaines d’amenorrhee, adressee dans notre service en juillet 2013 pour bilan d’une 2e poussee d’erytheme noueux associee a des diarrhees glaireuses non sanglantes. Elle presentait comme antecedents une MAI de forme generalisee a anticorps anti-recepteur de l’acetylcholine (RaC) positifs pharmacoresistante ayant necessitee une thymectomie (hyperplasie sans thymome), une embolie pulmonaire sur thrombose veineuse iliaque externe gauche et 3 fausses couches spontanees (FCS) precoces non successives, avec bilan de thrombophilie negatif. Elle avait presente un episode similaire 6 mois auparavant. Elle avait arrete son traitement de fond par mycophenolate mofetil et anticholinesterasique au diagnostic de grossesse. Les symptomes evoluaient depuis 5 jours, avec une fievre a 38,5 °C, des episodes diarrheiques pluriquotidiens, avec un syndrome rectal, et un erytheme noueux. Elle presentait egalement une poussee de myasthenie avec un ptosis bilateral, une dysphonie pharyngee sans trouble de deglutition et une fatigabilite musculaire. Le reste de l’examen clinique etait normal. L’evaluation obstetricale ne retrouvait pas d’anomalies morphologiques, ni de signes de souffrance fœtale. Au niveau biologique, il existait un syndrome inflammatoire (CRP 150 mg/L, thrombocytose a 460 G/L). La recherche directe dans les selles de Campylobacter, Yersinia, Shigelle et Salmonelle etait negative, ainsi que les serologies VIH, VHB, VHC, Syphilis, le test Quantiferon, le dosage de l’ECA, la recherche d’anticorps anti-nucleaires, d’ANCA et d’ASCA. En raison de la grossesse et des antecedents de FCS, les explorations endoscopiques n’ont pu etre realisees. La biopsie des glandes salivaires accessoires (BGSA) mettait en evidence une granulomatose epithelioide et gigantocellulaire sans necrose caseeuse. Un traitement par Loperamide permettait de reduire la frequence des episodes diarrheiques a 3 par jour, avec regression de l’hyperthermie, du syndrome inflammatoire et de l’erytheme noueux. Un mois plus tard, la persistance des symptomes digestifs et du syndrome inflammatoire, l’apparition d’une aphtose buccale, amenent a la realisation d’un bilan endoscopique devant la suspicion de MC. Celui-ci retrouvait une pancolite ulcereuse sans atteinte ileale, avec intervalles de muqueuse saine et a predominance colique gauche et rectale, ainsi qu’une ulceration aphtoide œsophagienne. Les biopsies retrouvaient des lesions de colite avec reaction granulomateuse. Devant le diagnostic de MC active en cours de grossesse, une corticotherapie a 1 mg/kg/jour est debutee associee a de la Mesalazine. Un traitement par Azathioprine sera debute un mois plus tard. La grossesse aboutira a un accouchement a terme, par voie basse, sans complication maternelle ou fœtale. Discussion L’association d’une MC et d’une MAI a ete rapportee de facon rare mais non fortuite [2] . Le diagnostic de la MC peut etre difficile au cours de la grossesse si l’examen endoscopique ne peut etre realise. Des lesions granulomateuses sont mises en evidence dans plus de 75 % des cas avec atteinte buccale de la MC [3] . Dans notre observation, la presence de telles lesions nous a permis d’evoquer le diagnostic en l’absence d’examen endoscopique, alors qu’il n’existait pas de manifestations orobuccales initialement. Le risque de poussee de la MC au cours de la grossesse est determine par l’activite de la maladie avant la conception. L’arret intempestif du traitement immunosuppresseur au diagnostic de grossesse peut etre un facteur declenchant, comme ce fut le cas pour notre patiente [1] . Conclusion L’existence de lesions histologiques granulomateuses constitue un argument pour le diagnostic de MC, notamment lorsque les lesions endoscopiques sont non specifiques. Quand l’endoscopie n’est pas realisable, ces lesions peuvent etre mises en evidence sur une BGSA, y compris en l’absence d’atteinte orobuccale clinique.

The principal reasons for using public policies to stimulate the production of ethanol in North America are to lower greenhouse gas emissions, increase farm income through the introduction of a new market for farm commodities, promote rural development and diversification, and reduce consumer reliance on imported fossil fuels. All these policy objectives are satisfied to some extent by biofuel production and consumption in North America. However, the degree to which they are fulfilled is modest at best, and there are important negative consequences.

Considerable effort and money are devoted to developing alternative energy sources, such as wind power, solar power, cellulosic ethanol, and biofuels. This ebook is a collection of research papers on alternative energy sources presented at the Economics of Alternative Energy Sources and Globalization: The Road Ahead Conference that was held in November 2009 in Orlando, Florida. Thirty-three papers were presented by leading experts in the field, with about half being published in the e-book. Several of the papers explored the economics of biofuels produced from corn, sugarcane, and/or forestry materials. Two of the papers addressed the link between biofuel production and U.S. agricultural policy, and how biofuels could reduce U.S. Treasury costs even though biofuels increase food prices. International subsidies promote alternative fuel production (e.g., Brazil). This ebook should be a very useful resource for readers interested in alternative energy research and related economic policy.

The ferroresonance phenomenon shows at least two different steady states for the same applied voltage, depending on initial conditions. The Galerkin method is well suited for computing periodic steady states, but often shows difficulties in terms of initialization or convergence. To overcome these difficulties, a continuation method solution is proposed: the pseudo-arclength method. This method has been applied to draw certain characteristic curves (flux magnitude versus applied voltage) for the fundamental, third subharmonic, and third harmonic series ferroresonance case. A number of solution branches with the determination of limit points (turning and bifurcation points) are presented. >

A new external monitoring service has been developed combining the excellent features of optically stimulated luminescence (OSL) with the convenience of Panasonic readers. This article briefly reviews OSL, and describes the InLight personal dosimetry system and its introduction into the European market.

The patented Napcoe technology presented in this paper is designed to create in a continuous way 3D tailored sandwich structures while maintaining the production efficiency. The through-thickness reinforcement is obtained from regular fabrics. This process allows the production of complex preforms that can be post formed and impregnated with liquid resin using a closed molding production method or thermoformed in the case of thermoplastic composites.

Une patiente de 67 ans aux antecedents de prothese mecanique aortique et d’insuffisance cardiaque chronique s’est presentee aux urgences pour hyperthermie. La radiographie thoracique (Fig. 1A) retrouvait une opacite basale droite bien limitee a bord externe net, avec un refoulement mediastinal pouvant faire suspecter initialement un epanchement pleural cloisonne. Il existait une image aerique au sein de cette opacite. Le scanner thoracique (Fig. 1B) a pu mettre en evidence la presence d’une volumineuse hernie diaphragmatique de Morgagni-Larrey contenant l’angle colique droit, pour laquelle cette patiente a beneficie d’un traitement chirurgical sans complication. La hernie diaphragmatique de Morgagni-Larrey est une pathologie rare, qui represente 3 % de l’ensemble des hernies diaphragmatiques [1]. Sa localisation est toujours anterieure, au depend des deux zones de faiblesse diaphragmatique que sont les foramens de Morgagni (a droite) et de Larrey (a gauche). Lorsque la hernie est symptomatique, les signes rapportes sont le plus souvent d’ordre respiratoire, mais aussi digestif (pyrosis, vomissements, syndrome occlusif) ou cardiaque (douleur thoracique atypique, tamponnade) [1].

Recent advances in the field of tunable semiconductor lasers have stimulated research studies on new optical switching concepts and architectures making efficient use of the wavelength domain. In the specific case of ATM-type systems, cells (data packets) can be encoded in the wavelength domain so as to determine a physical path through the switching network (wavelength routing) [1,2]. However, the useful tuning range of semiconductor lasers is still restricted to 10-20 nm and thus the capacity of any switch fabric based on wavelength routing remains somewhat limited, in terms of number of available wavelength multiplexed channels. In order to increase further this capacity, the integrated wavelength converter (IWC), recently demonstrated by Kondo et al [3], is an attractive device which can be used, for instance, as an optical gateway between stages of a multistage wavelength switching network. Basically, the IWC is a tunable laser which is optically triggered by external light; if this external signal is carrying binary data via intensity modulation, the IWC translates the incoming signal into an image signal, the wavelength of which can be tuned by electrical means. The aim of this paper is to present new results on high speed optical triggering and wavelength switching using an IWC based on a new DBR laser featuring a saturable absorber section.

Les auteurs soutiennent ici que les politiques du gouvernement ont contribue a une forte croissance dansl’industrie du bœuf au Canada, mais aussi a la vulnerabilite de la structure de cette industrie, qui a conduita un chaos financier lors de la decouverte, en 2003, en Alberta, de l’encephalopathie spongieuse bovine(ESB). L’article decrit la genese du probleme, l’impact de la decouverte de l’ESB, les reponses desgouvernements federal et provinciaux et les effets aggravants du protectionnisme dont beneficient les marchesetrangers. Les auteurs mettent en lumiere les changements cles qui doivent etre realises si l’on veut qu’along terme le marche canadien ait des chances de succes dans la competition des marches au niveauinternational.The authors here argue that government policies helped to bring about a boom in the Canadian beef industry,but these policies also contributed to the industry’s vulnerable structure, which then led to financial chaoswith the discovery of BSE in Alberta in 2003. The paper describes the genesis of the problem, the impact ofthe discovery of BSE, the responses of the federal and provincial governments, and the exacerbating effectsof protectionism in foreign markets. The authors highlight key changes that must occur if Canadian beef isto compete successfully in the international marketplace over the long term.

Les travaux ont porte sur la mise au point d’une methode d'evaluation des doses absorbees dans les tissus d’un patient au cours d’un examen de tomodensitometrie. Ils ont ete faits en collaboration avec la Societe C.G.R. sur un tomodensitometre ND 8000 concu pour les examens de la tete et du cou. Des dosimetres photographiques et thermoluminescents et un « fantome crâne » en materiau equivalent tissu ont ete utilises pour effectuer les mesures. Cette etude a permis de definir un fantome pour les mesures de dose a effectuer sur site.

Formulas giving the impedance and admittance matrices of a system consisting of three underground single-core cables have already been proposed. By applying now classical methods, we deduce the wave-propagation modes in this system. The present paper differs from its predecessors in proposing: -a simplified method for working out propagation parameters (problem reduced to 2 dimensions instead of 6); -a definition of modes in the form of a "generalized concordia matrix" similar to what is done for overhead lines and having the advantage of greatly simplifying the calculation of the transient response of cables; - a definition and a method for calculating the impedances that characterize the modes. Furthermore, full-size tests, the results of which are given in the second part of this paper, have made it possible to check the validity of the hypothesis on which this study is based.

The nucleation and growth of voids during tensile straining has been studied in spheroidized carbon-steels. These results, and others from the literature, are compared with a simple theory of void nucleation and growth.

In this paper different methods are proposed for estimating the risk of failure on lines caused by switching overvoltages. These methods correspond to various degrees of simplification. They are compared in study of a single particular case in order to deduce which the most practical one that gives satisfactory results.

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