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Herbivore attack is widely known to reduce food quality and to increase chemical defenses and other traits responsible for herbivore resistance. Inducible defenses are commonly thought to allow plants to forgo the costs of defense when not needed; however, neither their defensive function (increasing a plant's fitness) nor their cost-savings function have been demonstrated in nature. The root-produced toxin nicotine increases after herbivore attack in the native, postfire annual Nicotiana attenuata and is internally activated by the wound hormone, jasmonic acid. I treated the roots of plants with the methyl ester of this hormone (MeJA) to elicit a response in one member of each of 745 matched pairs of plants growing in native populations with different probabilities of attack from herbivores, and measured the lifetime production of viable seed. In populations with intermediate rates of attack, induced plants were attacked less often by herbivores and survived to produce more seed than did their uninduced counterparts. Previous induction did not significantly increase the fitness of plants suffering high rates of attack. However, if plants had not been attacked, induced plants produced less seed than did their uninduced counterparts. Jasmonate-induced responses function as defenses but are costly, and inducibility allows this species to forgo these costs when the defenses are unnecessary

Coyotes and lynx are the two most important mammalian predators of snowshoe hares throughout much of the boreal forest in North America. Populations of hares cycle in abundance, with peaks in density occurring every 8-11 yr, and experimental results suggest that predation is a necessary factor causing these cycles. We measured the numerical responses of coyotes and lynx during a cyclic fluctuation of hare populations in the southwest Yukon, to determine their effect on the cyclic dynamics. We used snow-tracking, track counts, and radio telemetry to directly examine changes in the numbers, population dynamics, and movements. Numbers of coyotes varied 6-fold and those of lynx 7.5-fold during a 26-44-fold fluctuation in numbers of hares, and the abundances of both predators were maximal a year later than the peak in numbers of snowshoe hares. Cyclic declines in numbers of coyotes were associated with lower reproductive output and high emigration rates. Likewise, few to no kits were produced by lynx after the second winter of declining numbers of hares. High emigration rates were characteristic of lynx during the cyclic peak and decline, and low in situ survival was observed late in the decline. The delayed numerical responses of both \"generalist\" coyotes and \"specialist\" lynx were therefore similar, and would contribute to the cyclic dynamics.

1 The effects of resource competition and herbivory on a target species, Triglochin maritima, were studied along a productivity gradient of vegetation biomass in a temperate salt marsh. 2 Transplants were used to measure the impact of grazing, competition and soil fertility over two growing seasons. Three parts of the marsh were selected to represent different successional stages; Triglochin reached local dominance at intermediate biomass of salt-marsh vegetation. At each stage, three competition treatments (full plant competition, root competition only, and no competition) and three grazing treatments (full grazing, no grazing on Triglochin, and no grazing on Triglochin or neighbours) were applied to both seedlings and mature plants. 3 Competition and herbivory reduced biomass and flowering of Triglochin. The impact of grazing was strongest at the stage with the lowest biomass, while both herbivory and competition had a significant impact at the stage with the highest biomass. When plants were protected from direct herbivory, competition operated at all three successional stages. 4 Grazing reduced light competition when vegetation biomass was low or intermediate, but at high biomass there was competition for light even when grazing occurred. Herbivore exclusion increased the effects of plant competition. Except at low biomass, the negative impact of plant competition on Triglochin performance was greater than the positive effect of not being grazed. 5 Grazing played a minor role in seedling survival and establishment which were largely controlled by competitive and facilitative effects. 6 Once established, the persistence of Triglochin will be determined largely by grazing. Intense grazing in the younger marsh and increasing competition for light in the older marsh will restrict the distribution to sites with intermediate biomass.

We measured the density changes of 22 species of vertebrates during a snowshoe cycle in northern Canada. Hares were the dominant herbivore in the system and changes in their numbers were correlated with changes in numbers of arctic ground squirrel, spruce grouse, ptarmigan, lynx, coyote, great horned owl, goshawk, raven and hawk owl. Hare numbers were not correlated with numbers of red-backed vole which showed peaks during the low, increase, and early decline phases of the hare cycle. Hawk owls were the only predator whose numbers correlated with changes in red-backed voles while boreal owls and weasels were correlated with densities of Microtus. Red squirrel, American kestrel, red-tailed hawk, northern harrier, wolverine, magpie, and gray jay showed no correlation with hare or vole numbers. We conclude that species in the boreal forests of Canada do not exhibit the strong synchrony found between voles and other members of the vertebrate community in northern Fennoscandia. We discuss some of the possible reasons for these differences.

Les produits du troisieme trimestre ont augmente pour se chiffrer a 76,8 millions $ comparativement a 48,0 millions $ pour la meme periode de l'exercice precedent. Le benefice avant elements hors tresorerie, sur une base comparable a l'exercice precedent, s'est accru de plus de 60 %, passant de 23,1 millions $ a 37,4 millions $. Les resultats du Fonds pour le troisieme trimestre rendent compte de l'ajout, le 31 aout 2009, de 15 nouvelles installations hydroelectriques ainsi que de modifications de contrats qui ont augmente le tarif que le Fonds recoit pour l'electricite produite a ses installations de La Lievre et de Mississagi. L'augmentation de tarif devrait accroitre considerablement les produits et les flux de tresorerie du Fonds pour les exercices futurs. En contrepartie de l'augmentation de tarif, le Fonds a verse une somme de 349 millions $, laquelle a ete comptabilisee a titre de charge ponctuelle au cours du trimestre. L'acquisition et les modifications de contrats ont contribue 8,8 millions $ au benefice avant elements hors tresorerie pour le mois de septembre. Le present communique de presse comprend de l'information et des enonces prospectifs au sens des lois canadiennes sur les valeurs mobilieres. Les enonces prospectifs peuvent comprendre des estimations, des plans, des attentes, des opinions, des previsions, des projections, des indications ou d'autres enonces qui ne sont pas des enonces de fait. Les enonces prospectifs contenus dans le present communique de presse comprennent des enonces concernant des benefices et flux de tresorerie attendus, des charges et des investissements attendus, les acquisitions de 2009 et leur incidence sur l'entreprise, la situation financiere et la situation fiscale du Fonds. Les enonces prospectifs peuvent etre identifies par l'utilisation de mots comme \"continu\", \"positionner\", \"attendu\", \"compter\", des verbes au futur ou des variations de ces mots et expressions. Bien que le Fonds croie que les resultats, le rendement ou les realisations futurs prevus exprimes ou sous-entendus par l'information et les enonces prospectifs sont fondes sur des hypotheses et des attentes raisonnables, il ne peut garantir que ces attentes se reveleront exactes. Le lecteur ne doit pas se fier indument a cette information ou a ces enonces prospectifs, car cette information et ces enonces prospectifs comportent des risques connus et inconnus, des incertitudes et d'autres facteurs par suite desquels les resultats, le rendement ou les realisations reels du Fonds peuvent differer de facon importante des resultats, du rendement ou des realisations futurs prevus exprimes ou sous-entendus par l'information et les enonces prospectifs. Des facteurs par suite desquels les resultats reels pourraient differer sensiblement de ceux envisages ou sous-entendus par les enonces prospectifs incluent, notamment, le risque associe aux acquisitions de 2009; les changements a l'hydrologie et au regime des vents; une panne d'equipement; un manquement par les contreparties a executer leurs obligations contractuelles et un manquement par le Fonds a remplacer les contrats; la dependance du Fonds envers Energie renouvelable Brookfield Inc. et les conflits d'interets potentiels entre Energie renouvelable Brookfield Inc. et le Fonds; l'omission, par le Fonds, de decouvrir des obligations associees aux acquisitions et l'incapacite du Fonds d'integrer avec succes de telles acquisitions; et d'autres risques et facteurs detailles de temps a autre dans les documents deposes par le Fonds, y compris la notice annuelle du Fonds datee du 20 mars 2009 sous la rubrique \"Facteurs de risque\" et le rapport de gestion pour l'exercice termine le 31 decembre 2008 sous les rubriques \"Environnement de l'entreprise\" et \"Facteurs de risque\". A noter que la liste precedente des facteurs importants susceptibles d'influer sur les resultats futurs n'est pas exhaustive. Sauf s'il y est tenu par la loi, le Fonds decline toute obligation de mettre a jour publiquement ou de reviser toute information ou tout enonce prospectif, qu'ils soient ecrits ou verbaux, que ce soit par suite de nouvelles informations, d'evenements futurs ou encore pour d'autres raisons.

Des facteurs par suite desquels les resultats reels pourraient differer sensiblement de ceux envisages ou sous-entendus par les enonces prospectifs incluent, notamment, le risque que la cloture de l'operation n'ait pas lieu et d'autres risques associes a l'operation concernant la realisation des avantages prevus par suite de celle-ci; les risques lies a l'operation et a la conversion possible du Fonds en societe par actions; les changements a l'hydrologie et au regime des vents; une panne d'equipement; un manquement par les contreparties a executer leurs obligations contractuelles et un manquement par le Fonds a remplacer les contrats; la dependance du Fonds envers Energie renouvelable Brookfield Inc. et les conflits d'interets potentiels entre Energie renouvelable Brookfield Inc. et le Fonds; l'omission, par le Fonds, de decouvrir des obligations associees aux acquisitions et l'incapacite du Fonds d'integrer avec succes de telles acquisitions; et d'autres risques et facteurs detailles de temps a autre dans les documents deposes par le Fonds, y compris le prospectus simplifie date du 16 juillet 2009 sous la rubrique \"Facteurs de risque\"; la notice annuelle du Fonds datee du 20 mars 2009 sous la rubrique \"Facteurs de risque\"; et le rapport de gestion pour l'exercice termine le 31 decembre 2008 sous les rubriques \"Environnement de l'entreprise\" et \"Facteurs de risque\". A noter que la liste precedente des facteurs importants susceptibles d'influer sur les resultats futurs n'est pas exhaustive. Sauf s'il y est tenu par la loi, le Fonds decline toute obligation de mettre a jour publiquement ou de reviser toute information ou tout enonce prospectif, qu'ils soient ecrits ou verbaux, que ce soit par suite de nouvelles informations, d'evenements futurs ou encore pour d'autres raisons.

Models of community organization involve variations of the top-down (predator control) or bottom-up (nutrient limitation) hypotheses. Verbal models, however, can be interpreted in different ways leading to confusion. Therefore, we predict from first principles the range of possible trophic level interactions, and define mathematically the instantaneous effects of experimental perturbations. Some of these interactions are logically and biologically unfeasible. The remaining set of 27 feasible models is based on an initial assumption, for simplicity, of linear interactions between trophic levels. Many more complex and non-linear models are logically feasible but, for parsimony, simple ones are tested first. We use an experiment in the boreal forest of Canada to test predictions of instantaneous changes to trophic levels and distinguish between competing models. Seven different perturbations systematically removed each trophic level or, for some levels, supplemented them. The predictions resulting from the perturbations were concerned with the direction of change in biomass in the other levels. The direct effects of each perturbation produced strong top-down and bottom-up changes in biomass. At both the vegetation and herbivore levels top-down was stronger than bottom-up despite some compensatory growth stimulated by herbivory. The combination of experiments produced results consistent with two-way (reciprocal) interactions at each level. Indirect effects on one or two levels removed from the perturbation were either very weak or undetectable. Top-down effects were strong when direct but attenuated quickly. Bottom-up effects were less strong but persisted as indirect effects to higher levels. Although the 'pure reciprocal' model best fits our results for the boreal forest system different models may apply to different ecosystems around the world.

This systematic review examines the findings that children with orofacial clefts have lower neurodevelopmental and academic outcomes compared to unaffected peers, examining trends by age.

\"You've got to love it. I do, good or bad. No, I couldn't ever move,\" she said. \"We had a couple of wet years in between, but we just haven't been able to get any continuity of any kind of climate, so it's either been two years too wet and the rest of it, the other 13, too dry.\" \"We've still got our ewes left, that's all we've got - our breeding stock, that's all we've got left,\" he said.

QUEBEC, le 18 juillet /CNW Telbec/ - Le Centre d'expertise hydrique du Quebec (CEHQ), une agence du ministere du Developpement durable, de l'Environnement et des Parcs, annonce aux usagers du reservoir Mitchinamecus que des travaux de refection s'effectueront du 31 juillet au 27 octobre 2006 au barrage Brodrick, situe sur le ruisseau [La Lievre] Loutre, dans la region des Laurentides.