| 1. |
- Anniballi, F., et al.
(author)
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Management of animal botulism outbreaks : From clinical suspicion to practical countermeasures to prevent or minimize outbreaks
- 2013
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In: Biosecurity and bioterrorism. - : Mary Ann Liebert Inc. - 1538-7135 .- 1557-850X. ; 11:SUPPL. 1, s. S191-S199
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Journal article (peer-reviewed)abstract
- Botulism is a severe neuroparalytic disease that affects humans, all warm-blooded animals, and some fishes. The disease is caused by exposure to toxins produced by Clostridium botulinum and other botulinum toxin-producing clostridia. Botulism in animals represents a severe environmental and economic concern because of its high mortality rate. Moreover, meat or other products from affected animals entering the food chain may result in a public health problem. To this end, early diagnosis is crucial to define and apply appropriate veterinary public health measures. Clinical diagnosis is based on clinical findings eliminating other causes of neuromuscular disorders and on the absence of internal lesions observed during postmortem examination. Since clinical signs alone are often insufficient to make a definitive diagnosis, laboratory confirmation is required. Botulinum antitoxin administration and supportive therapies are used to treat sick animals. Once the diagnosis has been made, euthanasia is frequently advisable. Vaccine administration is subject to health authorities' permission, and it is restricted to a small number of animal species. Several measures can be adopted to prevent or minimize outbreaks. In this article we outline all phases of management of animal botulism outbreaks occurring in wet wild birds, poultry, cattle, horses, and fur farm animals. © 2013, Mary Ann Liebert, Inc.
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| 2. |
- Barbero-Palacios, Laura, et al.
(author)
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Herbivore diversity effects on Arctic tundra ecosystems : a systematic review
- 2024
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In: Environmental Evidence. - : BioMed Central (BMC). - 2047-2382. ; 13:1
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Research review (peer-reviewed)abstract
- Background: Northern ecosystems are strongly influenced by herbivores that differ in their impacts on the ecosystem. Yet the role of herbivore diversity in shaping the structure and functioning of tundra ecosystems has been overlooked. With climate and land-use changes causing rapid shifts in Arctic species assemblages, a better understanding of the consequences of herbivore diversity changes for tundra ecosystem functioning is urgently needed. This systematic review synthesizes available evidence on the effects of herbivore diversity on different processes, functions, and properties of tundra ecosystems.Methods: Following a published protocol, our systematic review combined primary field studies retrieved from bibliographic databases, search engines and specialist websites that compared tundra ecosystem responses to different levels of vertebrate and invertebrate herbivore diversity. We used the number of functional groups of herbivores (i.e., functional group richness) as a measure of the diversity of the herbivore assemblage. We screened titles, abstracts, and full texts of studies using pre-defined eligibility criteria. We critically appraised the validity of the studies, tested the influence of different moderators, and conducted sensitivity analyses. Quantitative synthesis (i.e., calculation of effect sizes) was performed for ecosystem responses reported by at least five articles and meta-regressions including the effects of potential modifiers for those reported by at least 10 articles.Review findings: The literature searches retrieved 5944 articles. After screening titles, abstracts, and full texts, 201 articles including 3713 studies (i.e., individual comparisons) were deemed relevant for the systematic review, with 2844 of these studies included in quantitative syntheses. The available evidence base on the effects of herbivore diversity on tundra ecosystems is concentrated around well-established research locations and focuses mainly on the impacts of vertebrate herbivores on vegetation. Overall, greater herbivore diversity led to increased abundance of feeding marks by herbivores and soil temperature, and to reduced total abundance of plants, graminoids, forbs, and litter, plant leaf size, plant height, and moss depth, but the effects of herbivore diversity were difficult to tease apart from those of excluding vertebrate herbivores. The effects of different functional groups of herbivores on graminoid and lichen abundance compensated each other, leading to no net effects when herbivore effects were combined. In turn, smaller herbivores and large-bodied herbivores only reduced plant height when occurring together but not when occurring separately. Greater herbivore diversity increased plant diversity in graminoid tundra but not in other habitat types.Conclusions: This systematic review underscores the importance of herbivore diversity in shaping the structure and function of Arctic ecosystems, with different functional groups of herbivores exerting additive or compensatory effects that can be modulated by environmental conditions. Still, many challenges remain to fully understand the complex impacts of herbivore diversity on tundra ecosystems. Future studies should explicitly address the role of herbivore diversity beyond presence-absence, targeting a broader range of ecosystem responses and explicitly including invertebrate herbivores. A better understanding of the role of herbivore diversity will enhance our ability to predict whether and where shifts in herbivore assemblages might mitigate or further amplify the impacts of environmental change on Arctic ecosystems.
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| 3. |
- Niebuhr, B. B., et al.
(author)
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Estimating the cumulative impact and zone of influence of anthropogenic features on biodiversity
- 2023
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In: Methods in Ecology and Evolution. - : British Ecological Society. - 2041-210X. ; 14, s. 2362-2375
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Journal article (peer-reviewed)abstract
- The concept of cumulative impacts is widespread in policy documents, regulations and ecological studies, but quantification methods are still evolving. Infrastructure development usually takes place in landscapes with preexisting anthropogenic features. Typically, their impact is determined by computing the distance to the nearest feature only, thus ignoring the potential cumulative impacts of multiple features. We propose the cumulative ZOI approach to assess whether and to what extent anthropogenic features lead to cumulative impacts. The approach estimates both effect size and zone of influence (ZOI) of anthropogenic features and allows for estimation of cumulative effects of multiple features distributed in the landscape. First, we use simulations and an empirical study to understand under which circumstances cumulative impacts arise. Second, we demonstrate the approach by estimating the cumulative impacts of tourist infrastructure in Norway on the habitat of wild reindeer (Rangifer t. tarandus), a near-threatened species highly sensitive to anthropogenic disturbance. In the simulations, we showed that analyses based on the nearest feature and our cumulative approach are indistinguishable in two extreme cases: when features are few and scattered and their ZOI is small, and when features are clustered and their ZOI is large. The empirical analyses revealed cumulative impacts of private cabins and tourist resorts on reindeer, extending up to 10 and 20 km, with different decaying functions. Although the impact of an isolated private cabin was negligible, the cumulative impact of ‘cabin villages’ could be much larger than that of a single large tourist resort. Focusing on the nearest feature only underestimates the impact of ‘cabin villages’ on reindeer. The suggested approach allows us to quantify the magnitude and spatial extent of cumulative impacts of point, linear, and polygon features in a computationally efficient and flexible way and is implemented in the oneimpact R package. The formal framework offers the possibility to avoid widespread underestimations of anthropogenic impacts in ecological and impact assessment studies and can be applied to a wide range of spatial response variables, including habitat selection, population abundance, species richness and diversity, community dynamics and other ecological processes. © 2023 The Authors. Methods in Ecology and Evolution published by John Wiley & Sons Ltd on behalf of British Ecological Society.
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| 4. |
- Skarin, A, et al.
(author)
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Light and electron microscopic studies of anaerobic curved bacteria isolated from the vagina
- 1984
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In: Scandinavian Journal of Urology. - 0300-8886. ; 86, s. 59-64
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Journal article (peer-reviewed)abstract
- Twenty strains of anaerobic curved rods isolated from vaginal secretion were studied with light and transmission electron microscopy. Ten of the strains were of a short (approx. 1.5 microns) Gram-variable type, while ten were of a long (approx. 3 microns) Gram-negative type. The former had one to four flagella and the latter between one and eight. The flagella originated from the concave aspect of the cells. Thin sections of both types of bacteria revealed an approximately 30 nm thick cell wall with no outer membrane, similar to that of most Gram-positive bacteria. An electron-dense zone in the middle of the cell wall, atypical of Gram-positive bacteria, was found, however. Amorphous and electron-translucent cytoplasmic inclusions, not membrane-enclosed, were detected. These inclusions stained metachromatically with Albert's stain.
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| 5. |
- Lindén, Elin, et al.
(author)
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Circum-Arctic distribution of chemical anti-herbivore compounds suggests biome-wide trade-off in defence strategies in Arctic shrubs
- 2022
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In: Ecography. - : John Wiley & Sons. - 0906-7590 .- 1600-0587. ; :11
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Journal article (peer-reviewed)abstract
- Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top–down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non-resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements limit our current understanding of how much of the circum-Arctic variation in defence compounds is explained by taxa or defence functional groups (resinous/non-resinous). We measured circum-Arctic chemical defence and leaf digestibility in resinous (Betula glandulosa, B. nana ssp. exilis) and non-resinous (B. nana ssp. nana, B. pumila) shrub birches to see how they vary among and within taxa and functional groups. Using liquid chromatography–mass spectrometry (LC–MS) metabolomic analyses and in vitro leaf digestibility via incubation in cattle rumen fluid, we analysed defence composition and leaf digestibility in 128 samples from 44 tundra locations.We found biogeographical patterns in anti-herbivore defence where mean leaf triterpene concentrations and twig resin gland density were greater in resinous taxa and mean concentrations of condensing tannins were greater in non-resinous taxa. This indicates a biome-wide trade-off between triterpene- or tannin-dominated defences. However, we also found variations in chemical defence composition and resin gland density both within and among functional groups (resinous/non-resinous) and taxa, suggesting these categorisations only partly predict chemical herbivore defence. Complex tannins were the only defence compounds negatively related to in vitro digestibility, identifying this previously neglected tannin group as having a potential key role in birch anti-herbivore defence.We conclude that circum-Arctic variation in birch anti-herbivore defence can be partly derived from biogeographical distributions of birch taxa, although our detailed mapping of plant defence provides more information on this variation and can be used for better predictions of herbivore effects on Arctic vegetation.
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| 6. |
- Skarin, A
(author)
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Antigenic and biochemical characteristics of Mobiluncus mulieris and Mobiluncus curtisii
- 1986
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In: Acta pathologica, microbiologica, et immunologica Scandinavica. Section B, Microbiology. - : Wiley. - 0108-0180. ; 94:3, s. 33-127
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Journal article (peer-reviewed)abstract
- Twenty-four strains of Mobiluncus mulieris and 27 strains of Mobiluncus curtisii were tested with respect to 6 different biochemical characteristics: arginin-decarboxylase activity, beta-galactosidase activity, synergistic hemolysis with Staphylococcus aureus, hydrolysis of hippurate, migration through soft agar and reduction of nitrate. Antigens of the same strains, prepared by ultrasonication, were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed by immunoblotting using polyclonal rabbit antisera against two of the M. mulieris strains and five of the M. curtisii strains. Two different strongly reacting protein antigens could be detected in the M. mulieris strains. These strains could be separated into three groups based on the possession of either of the two antigens or both. In the M. curtisii strains, 10 strongly reacting protein antigens could be detected. Four strains possessed only one of these antigens, one did not possess any, while the remaining strains possessed different sets of 9 of them. Within each species common protein antigens were detected. No antigens were found which were shared by both species. The biochemical characteristics studied could not differentiate between the antigenic groups in any of the species. None of the antigenic subgroups of M. curtisii found in the present study was identical with any of the two subspecies (curtisii and holmesii) which have been proposed.
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| 7. |
- Skarin, A., et al.
(author)
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Summer habitat preferences of GPS-collared reindeer Rangifer tarandus tarandus
- 2008
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In: Wildlife Biology. ; 14, s. 1-15
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Journal article (peer-reviewed)abstract
- Reindeer Rangifer tarandus tarandus husbandry in Sweden commonly uses the Scandinavian mountain chain as grazing area during the snow-free season and the coniferous forests in the east during winter. Current knowledge of habitat use by reindeer is primarily based on traditional or local knowledge, or on investigations carried out on wild reindeer and caribou in other parts of the world. We identified spatial and temporal habitat use of free-ranging semi-domesticated reindeer by following 48 GPS-equipped reindeer in three summer ranges in the Swedish reindeer herding area. The GPS equipment registered positions every hour or every second hour, during two snow-free seasons. The GPS-collared reindeer were randomly chosen from herds with several thousand animals. Estimated home-range utilisation distributions were used to fit resource utilisation functions (RUFs) including various topographical features, vegetation types, and the vicinity to water and hiking trails. The GPS-equipped reindeer used different parts of the range throughout the snow-free season. Preferred vegetation types were consistently meadows, grass heaths, and other heaths. Avoided vegetation types were all types of forests, sparsely vegetated areas, and bare rocks. The reindeer were seemingly indifferent to hiking trails within their home ranges, which, however, usually coincided with preferred vegetation types, but they avoided areas with houses and holiday huts during early summer. Later in the season, the reindeer preferred higher elevated areas where human constructions were sparse. The home ranges of the GPS-equipped reindeer overlapped considerably during early parts of the season, indicating a dense use of the range by the entire herds. Crowding within the herds appeared to make individual reindeer select non-optimal habitats. However, in our study, we found a nonsignificant tendency of less predictable individual home ranges when there were large range overlaps. Vegetation types, direction of slopes, time within the season and the possibilities of avoiding insect harassment appear to be key factors for predicting valuable reindeer habitats in novel areas in a land management context.
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| 8. |
- Skarin, A, et al.
(author)
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Vaginal lactobacilli inhibiting growth of Gardnerella vaginalis, Mobiluncus and other bacterial species cultured from vaginal content of women with bacterial vaginosis
- 1986
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In: Acta pathologica, microbiologica, et immunologica Scandinavica. Section B, Microbiology. - : Wiley. - 0108-0180. ; 94B:6, s. 399-403
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Journal article (peer-reviewed)abstract
- On a solid agar medium the growth-inhibitory effect of 9 Lactobacillus strains cultured from vaginal content was tested on bacteria cultured from vaginal content of women with bacterial vaginosis: Mobiluncus, Gardnerella vaginalis, Bacteroides and anaerobic cocci. Inhibition zones were observed in the growth of all of the strains isolated from women with bacterial vaginosis around all lactobacilli. The inhibitory effect of the lactobacilli was further tested on various anaerobic and facultatively anaerobic species, both type strains and fresh extragenitally cultured strains. Four Bacteroides fragilis strains as well as 2 out of 4 Staphylococcus aureus strains were clearly inhibited by the lactobacilli. The inhibition zones were generally wider at pH 5.5 than at 6.0. For all inhibited strains, (the S. aureus excepted) a low pH on the agar around the lactobacilli correlated to wider growth-inhibition zones.
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| 9. |
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| 10. |
- Skarin, Hanna, et al.
(author)
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The workshop on animal botulism in europe
- 2013
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In: Biosecurity and bioterrorism. - : Mary Ann Liebert Inc. - 1538-7135 .- 1557-850X. ; 11:SUPPL. 1, s. S183-S190
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Journal article (peer-reviewed)abstract
- A workshop on animal botulism was held in Uppsala, Sweden, in June 2012. Its purpose was to explore the current status of the disease in Europe by gathering the European experts in animal botulism and to raise awareness of the disease among veterinarians and others involved in biopreparedness. Animal botulism is underreported and underdiagnosed, but an increasing number of reports, as well as the information gathered from this workshop, show that it is an emerging problem in Europe. The workshop was divided into 4 sessions: animal botulism in Europe, the bacteria behind the disease, detection and diagnostics, and European collaboration and surveillance. An electronic survey was conducted before the workshop to identify the 3 most needed discussion points, which were: prevention, preparedness and outbreak response; detection and diagnostics; and European collaboration and surveillance. The main conclusions drawn from these discussions were that there is an urgent need to replace the mouse bioassay for botulinum toxin detection with an in vitro test and that there is a need for a European network to function as a reference laboratory, which could also organize a European supply of botulinum antitoxin and vaccines. The foundation of such a network was discussed, and the proposals are presented here along with the outcome of discussions and a summary of the workshop itself. © 2013, Mary Ann Liebert, Inc.
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