Summer Activity Patterns of Three Rodents in the Southwestern Yukon

The small mammal communities of boreal forest in the SW Yukon are diverse and little is known about the underlying reasons for this species richness. Niche differentiation through staggered periods of activity is one way in which similar species may avoid potential interference competition. In this study we describe the activity pattern of three rodents (the deer mouse, the northern red-backed vole, and the singing vole) from the summer solstice to the autumnal equinox. Activity was measured on two white spruce plots by checking live-traps at 2 h intervals over a 24 h period. We did this at monthly intervals between June and September 1984. The deer mouse was strongly nocturnal throughout the summer, while the northern red-backed vole and the singing vole were active both day and night. During the nocturnal period of deer mouse activity, approximately 80% of the red-backed vole population was active, and we conclude that there is no evidence of temporal niche differentiation between these two species. Only deer mice showed a seasonal change in activity pattern. As the days became shorter, deer mice became active earlier, so that by September they were active 4 h earlier than they were in June.Key words: deer mice, Peromyscus maniculatus, northern red-backed vole, Clethrionomys rutilus, singing vole, Microtus miurus, activity time, Yukon, competitionMots clés: souris sylvestre, Peromyscus maniculatus, campagnol à dos roux boréal, Clethrionomys rutilus, campagnol chanteur, Microtus miurus, période d'activité, Yukon, compétitio

Evaluation of a Technique to Trap Lemmings Under the Snow

We attempted to live trap lemmings under the snow in their preferred winter habitat at two sites in the Canadian Arctic using chimney-like boxes. Lemmings used the boxes during winter, but we had very low trapping success in April and May. During spring trapping, in contrast to most of the winter, subnivean temperatures became colder than ambient air temperatures. We hypothesize that our low success in spring resulted from lemmings’ leaving the deeper snow areas where our boxes were located and moving to shallower snow or exposed tundra. We suggest that the trapping boxes could be successful if trapping occurred earlier during winter.Nous avons tenté de capturer des lemmings sous la neige dans leur habitat hivernal préféré en utilisant des boîtes en forme de cheminée à deux sites situés dans l’Arctique canadien. Les boîtes ont été utilisées par les lemmings durant l’hiver mais nous avons eu un très faible succès de capture en avril et mai. Contrairement à la majorité de l’hiver, les températures sous-nivales étaient plus froides que les températures de l’air pendant que nous avons trappé au printemps. Nous émettons l’hypothèse que notre faible succès au printemps est dû au déplacement des lemmings des sites de fort enneigement, où nos boîtes étaient installées, vers ceux de faible enneigement ou vers la toundra exposée. Nous suggérons que les boîtes de trappage pourraient être plus utiles si le trappage se faisait plus tôt au courant de l’hiver

Trophic Dynamics of the Boreal Forests of the Kluane Region

The trophic dynamics of the Yukon boreal forest have been under investigation at the Kluane Lake Research Station since 1973. We monitored and conducted experiments on the major species in this ecosystem, except the large mammals (for logistic reasons). The central problem has been to determine the causes of the 9 – 10 year cycle of snowshoe hares, and to achieve this we carried out several large-scale experiments manipulating food supplies, predator pressure, and soil nutrient availability to test hypotheses that food, predation, or habitat quality regulate populations. The hare cycle is driven top-down by predators, and most hares die because they are killed by predators. Predators also cause stress in female hares, and the stress response seems to be responsible for the loss of reproductive potential in the decline and low phases of the hare cycle. Many of the specialist predators and some herbivores in this ecosystem fluctuate with the hare cycle. Arctic ground squirrels do, but red squirrels do not, being linked closely to white spruce seed masting years. Small rodents fluctuate in numbers in two patterns. Red-backed voles and four species of Microtus voles have a 3 – 4 year cycle that seems to be driven by food supplies and social behaviour. Deer mice, in contrast, have fluctuated dramatically in the 38 years we have monitored them, but not cyclically. White spruce seed production varies with temperature and rainfall, but was not affected by adding nutrients in fertilizer. Global warming and reduced hare browsing in the last 20 years have helped to increase the abundance of shrubs in these forests. It will be challenging to predict how this system will change as climatic warming proceeds, because even closely related species in the same trophic level respond differently to perturbations. We recommend continued monitoring of the major species in these boreal forests.La dynamique trophique de la forêt boréale du Yukon fait l’objet d’une étude à la station de recherche du lac Kluane depuis 1973. Nous avons fait des expériences et surveillé les espèces importantes de cet écosystème, sauf en ce qui a trait aux principaux mammifères (pour des raisons de logistique). Le problème central a consisté à déterminer les causes du cycle de 9 à 10 ans du lièvre d’Amérique. Pour ce faire, nous avons effectué plusieurs expériences à grande échelle dans le cadre desquelles nous avons manipulé les disponibilités alimentaires, la pression exercée par les prédateurs et la disponibilité en nutriments dans le sol afin de mettre à l’épreuve les hypothèses selon lesquelles la nourriture, la prédation ou la qualité de l’habitat régularisent les populations. Le cycle du lièvre est dicté par les prédateurs de haut en bas, et la plupart des lièvres meurent parce qu’ils sont tués par les prédateurs. Par ailleurs, les prédateurs sont une source de stress chez les lièvres femelles, et la réaction au stress semble responsable de la perte de capacité de reproduction dans la phase du déclin et la phase basse du cycle du lièvre. Grand nombre des prédateurs spécialistes et certains herbivores de cet écosystème fluctuent en fonction du cycle du lièvre. C’est le cas du spermophile arctique, mais ce n’est pas le cas de l’écureuil roux, car il est étroitement lié aux années de paisson de graines d’épinette blanche. Le nombre de petits rongeurs fluctue en fonction de deux modèles. Le campagnol à dos roux et quatre espèces de campagnols Microtus ont un cycle de trois à quatre ans qui semble dicté par les disponibilités alimentaires et le comportement social, tandis que la souris sylvestre a connu d’énormes fluctuations pendant les 38 années qui ont fait l’objet d’une surveillance, sans toutefois afficher de cycles. La production de graines d’épinette blanche varie en fonction des températures et des chutes de pluie, mais n’a pas été influencée par l’ajout de nutriments au fertilisant. Le réchauffement planétaire et le broutage réduit des lièvres ces 20 dernières années ont aidé à accroître l’abondance d’arbustes dans ces forêts. Il sera difficile de prévoir comment ce système changera au fur et à mesure du réchauffement climatique, car même les espèces étroitement liées du même niveau trophique réagissent aux perturbations de manière différente. Nous recommandons la surveillance continue des principales espèces de ces forêts boréales

Effects of culling on spatial associations of Mycobacterium bovis infections in badgers and cattle

Bovine tuberculosis (TB), caused by Mycobacterium bovis, has serious consequences for Britain's cattle industry. European badgers (Meles meles) can transmit infection to cattle, and for many years the British government culled badgers in a series of attempts to reduce cattle infections. We investigated the impact of badger culling on the spatial distribution of M. bovis infection in badger and cattle populations in replicated areas in England. M. bovis infection was significantly clustered within badger populations, but clustering was reduced when culls were repeated across wide areas. A significant spatial association between M. bovis infections in badgers and cattle herds likewise declined across successive culls. These patterns are consistent with evidence that badgers are less territorial and range more widely in culled areas, allowing transmission to occur over greater distances. Prior to culling, M. bovis infections were clustered within cattle populations. Where badger culling was localised, and in unculled areas just outside widespread culling areas, cattle infections became less spatially clustered as badger culling was repeated. This is consistent with expanded badger ranging observed in these areas. In contrast, clustering of infection in cattle persisted over time on lands where badgers were repeatedly culled over wide areas. While this lack of a temporal trend must be interpreted with caution, it might reflect persistent infection within, and continued transmission between, cattle herds in areas where transmission from badgers to cattle had been reduced by badger culling. Continued spatial association of infections in cattle and badgers in such areas might partly reflect transmission from cattle. Synthesis and applications: Our findings confirm that badger culling can prompt spatial spread of M. bovis infection, a phenomenon likely to undermine the utility of this approach as a disease control measure. Possible evidence of transmission from cattle, both to other cattle and to badgers, suggests that improved cattle controls might yield multiple benefits for TB management

Herd-level risk factors of bovine tuberculosis in England and Wales after the 2001 foot-and-mouth disease epidemic

We present the results of a 2005 case–control study of bovine tuberculosis (bTB) breakdowns in English and Welsh herds. The herd management, farming practices, and environmental factors of 401matched pairs of case and control herds were investigated to provide a picture of herd-level risk factors in areas of varying bTB incidence. A global conditional logistic regression model, with region-specific variants, was used to compare case herds that had experienced a confirmed bTB breakdown to contemporaneous control herds matched on region, herd type, herd size, and parish testing interval. Contacts with cattle from contiguous herds and sourcing cattle from herds with a recent history of bTB were associated with an increased risk in both the global and regional analyses. Operating a farm over several premises, providing cattle feed inside the housing, and the presence of badgers were also identified as significantly associated with an increased bTB risk. Steps taken to minimize cattle contacts with neighboring herds and altering trading practices could have the potential to reduce the size of the bTB epidemic. In principle, limiting the interactions between cattle and wildlife may also be useful; however this study did not highlight any specific measures to implement

Jahrbuch des Archivs der deutschen Jugendbewegung. Erster Band

Das Archiv der deutschen Jugendbewegung dokumentiert seine Arbeit sowie die Beiträge von Tagungen seines Freundes- und Förderkreises. Im vorliegenden Band werden im Anschluss an eine grundsätzlich Klärung des Begriffes "Jugendbewegung" Verbindungen zwischen dieser mit der Musikpädagogik am Beispiel August Halms, mit der Kunst am Beispiel des Expressionismus sowie mit der Pädagogik am Beispiel Gustav Wynekens untersucht. Aus dem Archiv berichten der "Freundeskreis" und der wissenschaftliche Bearbeiter; außerdem werden das Kunstarchiv und der Nachlass von Eberhard Koebel-tusk vorgestellt. Abschließend werden die Neuerscheinungen der Jahre 1966 bis 1968 zum Thema "Jugendbewegung" aufgeführt

Predictors of Long-Term Opioid Use Among Patients With Painful Lumbar Spine Conditions

Our objective was to assess predictors of self-reported opioid use among patients with back pain due to lumbar disc herniation or spinal stenosis. Data was from the Spine Patient Outcomes Research Trial (SPORT), a multi-site observational study and randomized trial. We examined characteristics shown or hypothesized to be associated with opioid use. Using generalized estimating equations, we modeled associations of each potential predictor with opioid use at 12 and 24 months. At baseline, 42% of participants reported opioid use. Of these participants, 25% reported continued use at 12 months and 21% reported use at 24 months. In adjusted models, smoking (RR=1.9, p<0.001 at 12 months; RR=1.5, p=0.043 at 24 months) and non-surgical treatment (RR=1.7, p<0.001 at 12 months; RR=1.8, p=0.003 at 24 months) predicted long-term opioid continuation. Among participants not using opioids at baseline, incident use was reported by 8% at 12 and 7% at 24 months. We found no significant predictors of incident use at 12 or 24 months in the main models. In conclusion, nonsurgical treatment and smoking independently predicted long-term continued opioid use. To our knowledge, this is the first longitudinal study to assess predictors of long-term and incident opioid use among patients with lumbar spine conditions

The Reaction of a High‐Valent Nonheme Oxoiron(IV) Intermediate with Hydrogen Peroxide

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91353/1/5472_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91353/2/ange_201200901_sm_miscellaneous_information.pd

Coupling models of cattle and farms with models of badgers for predicting the dynamics of bovine tuberculosis (TB)

Bovine TB is a major problem for the agricultural industry in several countries. TB can be contracted and spread by species other than cattle and this can cause a problem for disease control. In the UK and Ireland, badgers are a recognised reservoir of infection and there has been substantial discussion about potential control strategies. We present a coupling of individual based models of bovine TB in badgers and cattle, which aims to capture the key details of the natural history of the disease and of both species at approximately county scale. The model is spatially explicit it follows a very large number of cattle and badgers on a different grid size for each species and includes also winter housing. We show that the model can replicate the reported dynamics of both cattle and badger populations as well as the increasing prevalence of the disease in cattle. Parameter space used as input in simulations was swept out using Latin hypercube sampling and sensitivity analysis to model outputs was conducted using mixed effect models. By exploring a large and computationally intensive parameter space we show that of the available control strategies it is the frequency of TB testing and whether or not winter housing is practised that have the most significant effects on the number of infected cattle, with the effect of winter housing becoming stronger as farm size increases. Whether badgers were culled or not explained about 5%, while the accuracy of the test employed to detect infected cattle explained less than 3% of the variance in the number of infected cattle