American marten (Martes americana (Turton, 1806)) are generally considered to be reliant upon and most successful in continuous late-successional coniferous forests. By contrast, young seral forests and deciduous-dominated forests are assumed to provide low-quality marten habitat, primarily as a result of insufficient structure, overhead cover, and prey. This study examined a moderate-density population of marten in northeastern British Columbia in what appeared to be comparatively low-quality, deciduous-dominated habitat, overgrown agricultural land primarily consisting of 30- to 40-year-old stands of regenerating trembling aspen (Populus tremuloides Michx.). Over 4 years, we monitored 52 radio-collared marten. The population appeared to be stable, as indicated by large numbers of adults, relatively constant densities, long-term residency of many individuals, low mortality rates, and older age structure. Relatively small home ranges (males, 3.3 km2; females, 2.0 km2) implied good habitat quality and prey availability. Shearing (removal of immature forest cover) of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level. Categorically, marten avoided nonforested cover types and preferred mature coniferous (>25% conifer) stands (7% of the study area) but otherwise appeared to use all forested stands relative to their availability, including extensive use of deciduous-dominated stands and deciduous stands <40 years of age. Thus, these young deciduous forests appeared to have sufficient structure, overhead cover, and prey to maintain moderate densities of resident marten on a long-term basis.

The effect of various reducing monosaccharides on the rate of atom transfer radical polymerization (ATRP) of butyl methacrylate is reported in this study. The addition of reducing sugars affects the rate of ATRP positively with a 100% increase in the rate of polymerization in some cases. In addition, these organic reducing agents have little effect on the molecular weight and molecular weight distribution of poly(butyl methacrylate) with polydispersity indexes that remain well below 1.2. A possible explanation for these observations is the ability of the reducing sugars to reduce part of the Cu2+ species, which deactivate the growing radicals, to Cu1+, thereby ensuring a shift in the equilibrium between active and dormant chains in the direction of the former with a resulting increase in the rate of reaction.

American marten (Martes americana (Turton, 1806)) are often associated with old-growth forests, but have been detected living in a young deciduous forest in northern British Columbia, where a previous coarse-scale analysis failed to detect significant habitat selection. To address this paradox, we examined fine-scale habitat selection for specific activities. We used radiotelemetry and snowtracking to identify sites that appeared to have been used for resting, foraging, scent marking, and traveling during the winters of 1998-1999 and 1999-2000. Then we conducted vegetation surveys at these activity sites and at nearby random locations and used logistic regression to measure selection. Based on the number of significant variables and model fit, we detected more selectivity by marten for resting than for foraging and scent-marking sites, and no selectivity for traveling. Marten exhibited selection for several habitat structures that are characteristic of older forests (e.g., rootballs and wide-diameter snags), but that can be retained in some manipulated forests. With the exception of wide-diameter snags (selected at both resting sites and scent marks), marten selected different habitat structures for each type of activity. These results may help to explain why marten are able to survive in this and other sites that provide seemingly unsuitable habitat.Résumé : La martre d'Amérique (Martes americana (Turton, 1806)) est souvent associée aux vieilles forêts, mais elle a aussi été observée dans une jeune forêt feuillue du nord de la Colombie-Britannique où une analyse précédente à petite échelle n'avait pas réussi à détecter une sélection significative de l'habitat. Pour comprendre ce paradoxe, les auteurs ont examiné, pour des activités spécifiques, la sélection de l'habitat à grande échelle. Les auteurs ont utilisé la radiotélémétrie et le pistage sur la neige pour identifier les sites qui semblaient avoir été utilisés pour le repos, l'alimentation, le marquage olfactif et les déplacements, durant les hivers 1998-1999 et 1999-2000. Ils ont ensuite fait des inventaires de végétation à ces sites d'activité et à des endroits choisis aléatoirement aux alentours, puis ils ont utilisé la régression logistique pour mesurer la sélection. En se basant sur le nombre de variables significatives et sur l'ajustement des modèles, ils ont détecté une plus grande sélectivité de la martre pour les sites de repos que pour les sites d'alimentation et de marquage olfactif et aucune sélectivité pour les sites de déplacement. La martre a sélectionné plusieurs structures d'habitat qui sont caractéristiques des forêts plus vieilles (p. ex., mottes de racines et chicots de fort diamètre), mais qui peuvent être maintenues artificiellement dans certaines forêts. À l'exception des chicots de fort diamètre (sélectionnés à la fois pour le repos et le marquage olfactif), la martre a sélectionné différentes structures d'habitat pour chaque type d'activité. Ces résultats peuvent aider à expliquer pourquoi la martre est capable de survivre dans ce s...

Bearing tests showed that lubricants containing sulphur and phosphorus extreme pressure (EP) additives reduce the life of rolling bearings compared with similar lubricants without EP additives. High-resolution electron microscopy revealed a remarkable difference of contact surface topography and microstructural changes between bearings tested with or without EP additives.

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