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Goyette Jean-Olivier Cimon-Morin Jérôme Mendes Poliana Thériault Maxime Pellerin Stéphanie Poulin Monique 《Landscape Ecology》2021,36(9):2691-2706
Landscape Ecology - Human activities have led to the degradation of wetlands, impinging on their capacity to deliver essential ecosystem services to society. Wetland restoration now appears an... 相似文献
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Many animals obtain reliable information about potential mates, including whether they are parasitised or not, mostly from olfactory cues in urine. Previous experiments with rodents have shown that females can detect parasites in males that are potentially transmissible during copulation, so that females can directly avoid infection by discriminating against parasitised males. Here, using choice tests, we examine whether female rats can distinguish males infected with the tapeworm Hymenolepis diminuta Rudolphi, 1819, a parasite with a complex life cycle and thus not directly transmissible among rats. Female rats tended to spend more time investigating the urine of non-parasitised males than that of parasitised males. The magnitude of the parasite burden in the infected males had no effect on the females' preference for the non-parasitised males. We also found that parasitised males had lover testosterone levels in their blood than non-parasitised males. These results suggest that females use cues in male urine reflecting either the presence of the parasite and/or lower testosterone levels to avoid parasitised males and possibly secure resistance genes for their offspring. 相似文献
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Poulin P 《Science (New York, N.Y.)》2005,309(5744):2174-2175
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Novel Colloidal Interactions in Anisotropic Fluids 总被引：2，自引：0，他引：2
Small water droplets dispersed in a nematic liquid crystal exhibit a novel class of colloidal interactions, arising from the orientational elastic energy of the anisotropic host fluid. These interactions include a short-range repulsion and a long-range dipolar attraction, and they lead to the formation of anisotropic chainlike structures by the colloidal particles. The repulsive interaction can lead to novel mechanisms for colloid stabilization. 相似文献
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Conservation strategies should be based on a solid understanding of processes underlying species response to landscape change.
In forests fragmented by agriculture, elevated nest predation rates have been reported in many forest bird species, especially
near edges. In intensively-managed forest landscapes, timber harvesting might also be associated with negative edge effects
or broader “context” effects on some species when the matrix provides additional resources to their major nest predators.
In this study, we hypothesized that proximity to a forest edge and proportion of cone-producing plantations will increase
nest predation risk in fragments of relatively undisturbed forest. We focused on the Brown Creeper (Certhia americana), an indicator species of late-seral forests. We compared habitat configuration and composition at four spatial scales (0.14,
0.5, 1 and 2 km) around 54 nests and related daily nest survival rate to the distance to the nearest forest edge, mean patch
size of late-seral forest (r = 141 m), proportion of non-forested lands (r = 141 m), density of maintained roads (r = 1 km), proportion of cone-producing spruce plantations (r = 2 km), and year. The best model included distance to the nearest edge and proportion of cone-producing plantations. Distance
of nests to the nearest edge was the best individual predictor of daily nest survival. A larger sample of nests showed a significant
threshold in distance to the nearest forest edge; nests located at least 100 m away were more likely to fledge young. These
results suggest that even in managed forest landscapes, matrix effects can be important and some bird species may exhibit
negative edge effects. 相似文献
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A control and eradication programme for foot-and-mouth disease (FMD) was initiated on a 1500-sow farm in Asia as an alternative to mass culling. The programme was based on mass vaccination and exposure to FMD virus to ensure the development of effective immunity throughout the population. Pigs are not long-term carriers of FMD virus and it should be eliminated by 21 days after infection. Entry of breeding stock was temporarily halted and the sow herd was partially depopulated in order to create a buffer between the infected and uninfected animals. After exposure to the virus and partial depopulation, the virus was eliminated through unidirectional pig flow and strict all-in/all-out procedures, and by thorough cleaning and disinfection of the buildings. Twelve months after the initial outbreak, the eradication plan was completed and successful. In parallel with the eradication programme, a small-scale isolated weaning project was carried out with the sow population that was moved out of the affected farm; 708 piglets were weaned to a separate facility 300 m away. No clinical signs of FMD were observed and the piglets remained serologically negative. 相似文献
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Braim AE Macdonald MH Bruss ML Stanley SD Giri JK Giri SN 《American journal of veterinary research》2008,69(7):952-960
OBJECTIVE: To characterize the plasma pharmacokinetics and clinical effects of pirfenidone administered IV in healthy horses. ANIMALS: 6 adult horses. PROCEDURES: A 15 mg/kg dose of pirfenidone was administered IV over 5 minutes. Physical variables were recorded and blood samples collected prior to infusion; 2.5 minutes after beginning infusion; at the end of infusion; and at 3, 6, 9, 12, 15, 20, 25, 30, 40, 50, 60, 75, and 90 minutes and 2, 2.5, 3, 4, 6, 8, 12, and 24 hours after completion of infusion. Plasma concentrations of pirfenidone and its metabolites were determined. RESULTS: Mild clinical effects, including tachycardia and muscle fasciculations, were observed during drug administration but stopped at the end of the infusion. Pirfenidone and 2 metabolites, hydroxypirfenidone and carboxypirfenidone, were detected by the end of the 5-minute infusion. Mean peak plasma concentration of pirfenidone was 182.5 micromol/L, detected at the end of the infusion. Mean peak plasma concentrations of hydroxypirfenidone and carboxypirfenidone were 1.07 and 3.4 micromol/L, respectively, at 40 minutes after infusion. No parent drug or metabolites were detected at 24 hours. Distribution of pirfenidone best fit a 2-compartment model, and the drug had mean +/- SEM elimination half-life of 86.0 +/- 4.7 minutes, mean body clearance of 6.54 +/- 0.45 mL/kg/min, and apparent volume of distribution at steady state of 0.791 +/- 0.056 L/kg. CONCLUSIONS AND CLINICAL RELEVANCE: Intravenous administration of pirfenidone was tolerated with transient adverse affects during infusion, and drug clearance was rapid. 相似文献
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Brigitte Poulin 《Biological conservation》2009,142(3):689-1609
The vulnerable Eurasian bittern Botaurus stellaris has recently benefited from conservation actions in several European countries. The Camargue in Mediterranean France holds 8000 ha of reed marshes and 50% of the French bittern population estimated at 300-350 booming males. Although reed cutting in Europe is a current practice, we provide the first analyses on habitat selection relative to reed exploitation. The contribution of reed harvesting and water management was assessed at a fine scale (digitized aerial photographs of 50-cm resolution) based on multi-modelling data analyses. GLMs applied to random and bittern points of 50-m radius showed that bitterns preferred areas with less than 10% open water enclosing 1-year reeds. Only in harvested reedbeds had the water management a significant impact on habitat selection, with bitterns avoiding areas dried during less than two months and flooded since less than 8 months. Water edge played a role in non-harvested reeds only, with bittern seeking for areas with the highest ratio water edge to open water. Although reed cutting is generally considered as detrimental in the short term, two 4-year experiments showed a marked increase in bitterns the first spring after cutting was interrupted. Based on these results, we propose various management scenarios that conciliate economic constraints of reed harvesters and protection of Eurasian bittern populations. 相似文献
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The life cycle of Hedruris spinigera Baylis, 1931 (Nematoda: Hedruridae) is determined here with the first formal identification of the parasite's intermediate host: the crustacean amphipod Paracorophium excavatum Thomson. Adult H. spinigera are redescribed from specimens collected from the stomach of fishes, Retropinna retropinna (Richardson) and Aldrichettaforsteri (Valenciennes), from Lake Waihola, New Zealand. Immature adults of the parasite collected from intermediate hosts (P. excavatum) are also described for the first time. The prevalence, abundance and intensity of infection of H. spinigera in several fish species are quantified along with the occurrence of P. excavatum, the parasite's intermediate host, in fish stomach contents. Although H. spinigera's transmission mode (trophic transmission) and fish diet potentially expose all fish species to infection, some level of host specificity must exist as parasite prevalence, abundance and intensity of infection vary greatly between potential definitive host species. We suggest here that the anatomy of the fish digestive tract and especially that of the stomach plays an important role in host suitability for H. spinigera. While P. excavatum is the only intermediate host in Lake Waihola, H. spinigera was found in six different fish species: Aldrichetta forsteri, Galaxias maculatus (Jenyns), Retropinna retropinna, Rhombosolea retiaria Hutton, Perca fluviatilis Linnaeus and Salmo trutta Linnaeus; although typical hedrurid attachment and mating positions were observed only in R. retropinna and A. forsteri. The limited distribution of H. spinigera is most likely due to that of its different host species (intermediate and definitive), all inhabitants of coastal fresh and brackish waters. 相似文献