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- O'Gorman, Eoin J., et al.
(author)
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Impacts of Warming on the Structure and Functioning of Aquatic Communities : Individual-to Ecosystem-Level Responses
- 2012
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In: Advances in Ecological Research, Vol 47. - : Elsevier. - 9780123983152 ; , s. 81-176
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Book chapter (peer-reviewed)abstract
- Environmental warming is predicted to rise dramatically over the next century, yet few studies have investigated its effects in natural, multi-species systems. We present data collated over an 8-year period from a catchment of geothermally heated streams in Iceland, which acts as a natural experiment on the effects of warming across different organisational levels and spatiotemporal scales. Body sizes and population biomasses of individual species responded strongly to temperature, with some providing evidence to support temperature size rules. Macroinvertebrate and meiofaunal community composition also changed dramatically across the thermal gradient. Interactions within the warm streams in particular were characterised by food chains linking algae to snails to the apex predator, brown trout These chains were missing from the colder systems, where snails were replaced by much smaller herbivores and invertebrate omnivores were the top predators. Trout were also subsidised by terrestrial invertebrate prey, which could have an effect analogous to apparent competition within the aquatic prey assemblage. Top-down effects by snails on diatoms were stronger in the warmer streams, which could account for a shallowing of mass-abundance slopes across the community. This may indicate reduced energy transfer efficiency from resources to consumers in the warmer systems and/or a change in predator-prey mass ratios. All the ecosystem process rates investigated increased with temperature, but with differing thermal sensitivities, with important implications for overall ecosystem functioning (e.g. creating potential imbalances in elemental fluxes). Ecosystem respiration rose rapidly with temperature, leading to increased heterotrophy. There were also indications that food web stability may be lower in the warmer streams.
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| 2. |
- Brodersen, Jakob, et al.
(author)
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Short-and long term niche segregation and individual specialization of brown trout (Salmo trutta) in species poor Faroese lakes
- 2012
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In: Environmental Biology of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 93:3, s. 305-318
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Journal article (peer-reviewed)abstract
- Trophic niche divergence is considered to be a major process by which species coexistence is facilitated. When studying niche segregation in lake ecosystems, we tend to view the niche on a one-dimensional pelagic-littoral axis. In reality, however, the niche use may be more complex and individual fidelity to a niche may be variable both between and within populations. In order to study this complexity, relative simple systems with few species are needed. In this paper, we study how competitor presence affects the resource use of brown trout (Salmo trutta) in 11 species-poor Faroese lakes by comparing relative abundance, stable isotope ratios and diet in multiple habitats. In the presence of three-spined sticklebacks (Gasterosteus aculeatus), a higher proportion of the trout population was found in the pelagic habitat, and trout in general relied on a more pelagic diet base as compared to trout living in allopatry or in sympatry with Arctic charr (Salvelinus alpinus). Diet analyses revealed, however, that niche-segregation may be more complex than described on a one-dimensional pelagic-littoral axis. Trout from both littoral and offshore benthic habitats had in the presence of sticklebacks a less benthic diet as compared to trout living in allopatry or in sympatry with charr. Furthermore, we found individual habitat specialization between littoral/benthic and pelagic trout in deep lakes. Hence, our findings indicate that for trout populations interspecific competition can drive shifts in both habitat and niche use, but at the same time they illustrate the complexity of the ecological niche in freshwater ecosystems.
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| 3. |
- Hermansson, Liselotte M. N., 1954-, et al.
(author)
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Swedish normative data for the Southampton Hand Assessment Procedure – SHAP
- 2014
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In: MEC'14. - Frederiction, New Brunswick, Canada : University of New Brunswick; Fredericton, Canada. - 9781551311760
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Conference paper (peer-reviewed)abstract
- Introduction: Today there is an increasing awareness of the need for validated instruments in upper limb prosthetics outcome assessments. One of the instruments suggested is the Southampton Hand Assessment Procedure (SHAP). In order for the clinicians to know how to interpret the results from the assessments, norms for different age groups are needed. Previously, normative data for SHAP has been reported for an English sample and work is underway from Slovenia. However, norms are only available for people up to 75 years of age, and no normative data is available for Sweden. Hence, the aim was to collect data also from people age 75 and older, and from Sweden.Methods: Participants and procedure — 58 persons (md age 52.5, range 20-92 years) participated in the study. Participants were recruited among students at Örebro University, staff at Örebro University Hospital, and people attending a community-based centre for senior citizens. Inclusion criteria were self-determined normal hand-function and no hand-impairment at time of testing. Data was collected according to the standardized procedure in the manual, and by one single "assessor" an OT-student. Instrumentation — The SHAPconsists of 26 tasks: 6 abstract objects in both lightweight and heavyweight form, and 14 simulated ADL-tasks. All tasks are representing one out of six grip-patterns. The subject is instructed to start and stop the timer before and after performing the task. An overall score, the Index of Functionality (IOF), is calculated based on the resulting times.Results: Mean IOF was 96.7. One-way ANOVA with index of functionality as dependent variable showed a statistical significant difference in dominant hand function between age groups.
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| 4. |
- Johansson, Kerstin, et al.
(author)
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"I can walk briskly and talk at the same time" - effects of Expiratory Muscle Strength Training (EMST) on respiration and speech in multiple sclerosis
- 2012
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In: Journal of Medical Speech-Language Pathology. - 1065-1438. ; 20:4, s. 70-76
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Journal article (peer-reviewed)abstract
- In this study, a single-subject design (A1-B-A2) was used for five participants (P1-P5) with multiple sclerosis (MS) with Expanded Disability Status Scale (EDSS) scores of 2 to 8 who performed expiratory muscle strength training (EMST). During phase B (6 weeks), all five trained using a positive-expiratory pressure threshold trainer (PEPTT) with a maximum resistance of 20 cm H2O. P4 and P5, with lower EDSS scores (2 and 3), then trained using the "EMST 150" with a maximum resistance of 150 cm H2O (phase C). After EMST, all five participants increased their expiratory muscle strength and their vocal intensity. Pl, P3, and P4 increased their phonation duration. P2, P4, and P5 increased their vocal stability. During phase C, the increase in performance was more marked, particularly for P4, whose performance was stabilized and showed improvement for all speech parameters. It is possible that the forceful exhalations resulted in improved regulation of expiratory airflow and thus better coordination of respiration and phonation. All five participants reported positive effects of the intervention: better respiration, improved voice and speech, and increased communicative participation. The results of this study indicate a need to further investigate the effects of EMST in a larger group of individuals with mild MS and speech dyspnea, dysphonia, or dysarthria.
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