Radiation inactivation of enzymes at low dose rates: Identical molecular weights of rat liver cytosolic and lysosomal neuraminidases

A low-dose-rate gamma source (⁶⁰Co) was calibrated with enzymes of known radiation inactivation behaviors and used for molecular weight determination of rat liver neuraminidase (EC 3.2.1.18). The method allows direct comparison of radiation inactivation of standard and unknown enzymes under identical experimental conditions. The membrane-bound lysosomal neuraminidase had the same molecular weight (M_r = 56,000 ± 8500) as the soluble cytosolic neuraminidase (M_r = 56,000 ± 7000) although they differ in their kinetic properties and substrate specificity.     

A method for rapid microassay of 3-hydroxy-3-methylglutaryl-CoA reductase activity

A method is devised for the separation of mevalonolactone (MVL) from hydroxymethylglutarate (HMG) in the assay of HMG-CoA reductase activity. The main steps in the procedure consist of absorbing the reaction mixture on the bottom part of a rectangular filter paper and selectively transfering the MVL into the top part of the paper by upward elution with toluene. Under the experimental conditions deseribed, MVL is recovered in an yield of approximately 60%, with little contamination with HMG. Among the advantages of the method are that it involves simple and very few manipulations, no internal standard is required to calculate the recovery of MVL, and simultaneous analyses of a large number of samples are possible.     

Management of Roadside Salt Pools to Reduce Moose-Vehicle Collisions

ABSTRACT Wildlife-vehicle collisions cause numerous human fatalities and injuries, and generate considerable expenses in property damage each year. Certain characteristics of the road and its surroundings are known to have an impact on collision probability. Roadside salt pools increase the risk of collision by attracting moose (Alces alces) to the side of the road. In the Laurentides Wildlife Reserve of Québec, Canada, roadside salt pools were drained and filled with rocks to deter moose from drinking. We surveyed 12 roadside salt pools during 3 consecutive summers (2003–2005) from mid-May to mid-August. Seven salt pools were managed in autumn 2004, and 5 pools were left untreated. We equipped all 12 sites with electronic apparatus that allowed us to detect moose attendance and study their behavior. We also measured physical, chemical, and environmental characteristics of these pools and other unvisited pools in order to correlate moose attendance with specific habitat criteria. We found that moose mostly attended roadside salt pools from mid-June to mid-July, with a decrease in August. Moose attendance was significantly correlated with visual obstruction toward the road and water availability. Management of the pools caused a decrease in mean length of time moose spent at them. Number of visits decreased significantly at night (by 90%), which was when most visits occurred, but not during the day. The proposed management practice prevented all visiting moose from drinking brackish water. These results suggest that moose should eventually lose interest in treated salt pools, therefore decreasing the risk of moose-vehicle collisions on the road.     

Moose Movement Rates Along Highways and Crossing Probability Models

ABSTRACT We developed and validated a density-adjusted spatial model to predict moose (Alces alces) highway-crossing probability to see if the model could be used as an index of moose-vehicle collision risk. We installed Global Positioning System telemetry collars on 47 moose in the north of the Laurentides Wildlife Reserve, Québec, for 2–36 months. We recorded only 84 highway crossings in spring (0.29% of 28,967 2-hr steps) and 122 crossings in summer (0.18% of 68,337 2-hr steps), despite a high sampling effort and having captured moose close to highways. Moose movement rates during movement steps crossing a highway were on average 3 times higher than during the steps preceding or following highway crossing. Paths used by moose when crossing a highway were characterized by a high proportion of food stands, low proportion of lakes and rivers, and topography typical of a valley. Highway-crossing sites were located in valleys with brackish pools and forest stands providing coniferous cover but a low proportion of lakes and rivers. We adjusted moose crossing probability for local variation in moose density using aerial survey data and assessed crossing probability along the highways in the entire Laurentides Wildlife Reserve. We tested the model using moose-vehicle accident data from 1990 to 2002. The relationship between the density-adjusted crossing probability and number of accidents was relatively loose at the 1-km scale but improved markedly when using longer highway sections (5–15 km; r > 0.80). Our results demonstrate that roads and their surroundings are perceived as low-quality habitat by moose. We also conclude that road segments installed along secondary valleys could be a highly strategic site to deploy mitigation measures such as fences and that it could be desirable to increase the width of road shoulders to reduce forest cover and to eliminate brackish pools to reduce cervid-vehicle collisions. We suggest using empirical data such as location of vehicle-wildlife collisions to plan mitigation measures at a fine scale.     

Late Ordovician-Early Silurian fluctuations in sea level from eastern Anticosti Island, Quebec

Over 1,000 m of Upper Ordovician to Lower Silurian mixed carbonate and clastic strata on Anticosti Island are nearly tectonically undisturbed, despite their proximity to the Northern Appalachians fronting Quebec's Gulf of St. Lawrence. Natural cliffs exposed along the coast and rivers in the eastern part of the island make a relatively conformable sequence belonging to the Ashgill and Llandovery Series. Fossil communities interpreted as depth-associated in life are especially repetitious in the Becscie, Gun River, Jupiter, and Chicotte Formations (Llandovery Series), and to a lesser degree in the Upper Vaureal and Ellis Bay Formations (Ashgill Series). Preliminary study of the pattern of changeovers in Eocoelia, Pentamerus and Stricklandia communities suggests that Anticosti seas deepened and shallowed three and a half times during the Early Silurian. High water peaks were reached during B₁-B₂, C₁-C₂ and C₄-C₅ times, with a final deepening trend beginning in late C₅ time. Age determinations of these events are based on the occurrence of graptolites (with some new records from Anticosti) keyed to the standard graptolite zones, and species of the Eocoelia lineage are also useful for correlation. The profile of the Anticosti sea-level curve compares well with other curves reconstructed from the Lower Silurian of New York, Michigan, and Iowa. Widespread synchronism in sea-level changes on the North American platform is thus corroborated.     

How did common ragweed (Ambrosia artemisiifolia L.) spread in Québec? A historical analysis using herbarium records

Aim To reconstruct the spread of common ragweed (Ambrosia artemisiifolia L.; Asteraceae) using herbarium specimens to document whether the habitat preferences of this plant have shifted through time. Location Southern Québec. Methods Herbarium specimens stored in the main herbaria of southern Québec were used to reconstruct the spread of common ragweed. All data (sampling location, year of sampling, habitat characteristics, etc.) were incorporated into a geographical information system. Maps indicating the spatial distribution of common ragweed were produced for four time periods. The cumulative number of locations was plotted against time to construct invasion curves. The sequence of habitats where herbarium specimens were collected was also reconstructed. Results A data base incorporating 707 common ragweed herbarium specimens was constructed for this study. The spread of common ragweed in most regions of southern Québec was initiated at the beginning of the 20th century. Herbarium specimens suggest that common ragweed first spread along river corridors. Specimens of common ragweed were not collected in agricultural fields before the mid‐1920s, nor along roads and railways before the mid‐1930s. The colonization of a large number of agricultural fields by common ragweed probably began with seed‐contaminated crops, but was certainly accelerated by the dispersal of seeds from populations growing along nearby roads. Main conclusions Herbarium specimens suggest that common ragweed has been present in southern Québec for at least 200 years, but the species was probably restricted to the Montréal area during the 19th century. It is likely that the development of the road network in Québec since the mid‐1930s significantly contributed to the spread of common ragweed. Controlling common ragweed solely in agricultural fields would not prevent the re‐infestation of crops, because roadsides would act as refuges for the weed.     

Area prioritization for biodiversity conservation in Québec on the basis of species distributions: a preliminary analysis

Results are presented which prioritize areas for potential protection in Québec on the basis of biodiversity considerations. These results are relevant to the ongoing public discussion in Québec about designating new parks and refuges so that the province may fulfil its obligations to Canada's Endangered Spaces Campaign. The prioritization algorithm used in this analysis is based on rarity and complementarity. It attempts to sample biodiversity in as area-efficient a way as possible. The biodiversity surrogates used here comprise a subset of 743 species for which data on spatial distributions are publicly available; the analysis begins with 394 species at risk. It is shown that: (i) the existing network of protected areas in Québec does a poor job of protecting these biodiversity surrogates; (ii) adding adjacent areas to this network will not be the optimal way of protecting these biodiversity surrogates; (iii) many of the areas that have highest priority are in southern Québec, which has a high human population density; (iv) because of (iii), designating parks may not be economically or sociologically feasible and more adaptive alternative conservation plans will have to be devised; (v) coastal areas, riparian habitats, and other wetlands should have high priority for protection but are currently very inadequately represented in the reserve network; (vi) there is some reason for concern about the clear-cut logging of boreal forests in northern Québec; and (vii) the islands, Île d'Anticosti and the Îles-de-la-Madeleine, emerge as being of very significant conservation value and plans for the protection of areas on them should be an immediate goal for biodiversity conservation in Québec.     

Coyote Habitat Selection and Management Implications for the Gaspésie Caribou

ABSTRACT Anthropogenic disturbances can promote establishment and growth of predator populations in areas where secondary prey can then become threatened. In this study, we investigated habitat selection of eastern coyotes (Canis latrans), a relatively new predator in the vicinity of an endangered population of caribou (Rangifer tarandus caribou). We hypothesized that coyotes in the boreal forest depend mainly on disturbed habitat, particularly that of anthropogenic origin, because these habitats provide increased food accessibility. Coyotes would likely take advantage of moose (Alces alces) carcasses, berries, and snowshoe hares (Lepus americanus) found in open habitats created by logging. To test these predictions, we described coyote diet and habitat selection at different spatial and temporal levels and then compared resource availability between habitats. To do so, we installed Global Positioning System radiocollars on 23 individual coyotes in the Gaspésie Peninsula, eastern Québec, Canada. Coyotes selected clear-cuts of 5–20 years and avoided mature coniferous forests both at the landscape and home-range levels. Clear-cuts of 5–20 years were found to contain a high availability of moose carcasses and berries, and vulnerability of snowshoe hares is known to increase in clear-cuts. The importance of these 3 food resources was confirmed by the characteristics of core areas used by coyotes and diet analysis. Moose remains were found at 45% of core areas and coyote diet comprised 51% moose on an annual basis. Anthropogenic disturbances in the boreal forest thus seem to benefit coyotes. Our results indicated that the relationship between coyotes and caribou likely involves spillover predation. This knowledge allows managers to consider spillover predation by coyotes as a possible threat for endangered caribou population when the predator depends mainly on habitat of anthropogenic origin and to suggest methods to alleviate it when developing management plans.