| 1. |
- Alatalo, Juha, 1966-, et al.
(författare)
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Pollen viability and limitation of seed production in a population of the circumpolar cushion plant, Silene acaulis (Caryophyllaceae)
- 2001
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Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 21:4, s. 365-372
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Tidskriftsartikel (refereegranskat)abstract
- Pollen viability among genders and limitation of female seed production in a natural trioecious population of the circumpolar cushion plant Silene acaulis was examined. Pollen viability was estimated by an in vitro pollen germination experiment. Both male and hermaphrodite flowers displayed large variation in pollen viability (0-53% in hermaphrodite and 0-54% in male flowers). There was a significant difference between genders in pollen viability: male plants had on average higher pollen viability than hermaphrodite plants. Resource and pollen limitation of seed production was studied by an experiment consisting of three treatments; (I) hand-pollination and removal of all other flowers on the cushion, (II) harid-pollination without removal of other flowers, and (III) open pollination without removal of flowers, Hand-pollination increased seed production, whereas removal of flowers had no effect on seed production. Abortion of pollinated ovules during seed development and seed mass did not differ among treatments. To control for effect of fruit number on seed production, data from naturally pollinated individuals was used. There was a positive correlation between both total number of seeds and fruit number, mean seed number per fruit and fruit number, respectively. These results indicate that seed production of S. acaulis is mainly limited by pollen availability whereas resource competition between fruits is not important as a limiting factor. The possible role of male quality differences between genders and pollen limitation of seed production for maintenance of trioecious reproductive systems is discussed.
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| 2. |
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| 3. |
- Bastholm Rahmner, Pia, et al.
(författare)
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Physicians perceptions of possibilities and obstacles prior to implementing a computerised drug prescribing support system
- 2004
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Ingår i: International journal of health care quality assurance incorporating leadership in helath services. - : Emerald. - 1366-0756 .- 2051-3135. ; 17:4, s. 173-179
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Tidskriftsartikel (refereegranskat)abstract
- Seeks to identify physicians' perceptions of possibilities and obstacles prior to implementing a computerised drug prescribing support system. Details a descriptive, qualitative study, with semi-structured individual interviews of 21 physicians in the Accident and Emergency Department of South Stockholm General Hospital. Identifies four descriptive categories for possibilities and obstacles. Concludes that gaining access to patient drug history enables physicians to carry out work in a professional way – a need the computerised prescription support system was not developed for and thus cannot fulfil. Alerts and producer-independent drug information are valuable in reducing workload. However, technical prerequisites form the base for a successful implementation. Time must be given to adapt to new ways of working.
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| 4. |
- Buijs, Jos, et al.
(författare)
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Localized changes in the structural stability of myoglobin upon adsorption onto silica particles, as studied with hydrogen/deuterium exchange mass spectrometry
- 2003
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 263:2, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- A new method is presented for monitoring the conformational stability of various parts of a protein that is physically adsorbed onto nanometer-sized silica particles. The method employs hydrogen/deuterium (H/D) exchange of amide hydrogens, a process that is extremely sensitive to structural features of proteins. The resulting mass increase is analyzed with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Higher structural specificity is obtained by enzymatically cleaving the adsorbed proteins prior to mass spectrometric analysis. The mass increases of four peptic fragments of myoglobin are followed as a function of the H/D exchange time. The four peptic fragments cover 90% of the myoglobin structure. Two of the peptic fragments, located in the middle of the myoglobin sequence and close to the heme group, do not show any adsorption-induced changes in their structural stability, whereas the more stable C- and N-terminal fragments are destabilized. Interestingly, for the N-terminal fragment, comprising residues 1–29, two distinct and equally large conformational populations are observed. One of these populations has a stability similar to that in solution (−23 kJ/mol), whereas the other population is highly destabilized upon adsorption (−11 kJ/mol).
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| 7. |
- Bäck, Hanna
(författare)
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Explaining Coalitions : Evidence and Lessons From Studying Coalition Formation in Swedish Local Government
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to better understand coalition formation. To date, a vast number of theories have been presented with the goal to explain coalition outcomes. For example, early coalition theories assumed that parties were motivated solely by the goal of attaining the power and prestige that come with being in office, and predicted that minimal winning coalitions would form. Later coalition theories are instead often based on the assumption that parties are interested in implementing a policy program.Three problems with much of the existing coalition research are identified and solved in this study. First, many coalition theories have only been evaluated on the data set of Western European national governments despite the fact that these theories often emerged from consideration of this same data set, which implies that these theories have not been subjected to proper evaluations. In this study, a new data set consisting of a large number of formation opportunities in Swedish local government is used to evaluate coalition theories. Second, few empirical investigations have focused on comparing alternative coalition explanations using careful controls. In this study several different statistical techniques are used to evaluate the relative importance of a number of important coalition variables. Third, coalition researchers have not focused on giving adequate causal explanations to coalition formation in terms of measuring both the causal effects and the causal mechanisms underlying these effects. In this thesis, a large-n statistical study is combined with in-depth case studies, which makes it possible to measure and isolate effects, and to investigate the mechanisms that explain these effects.The analyses performed here indicate that when explaining coalition formation we should take into account that parties are neither pure office-seekers nor pure policy-seekers. Instead, parties are driven by multiple goals. The results also indicate that we should consider that parties are concerned with the effects that coalitional choices may have on future election results. The results found here show that parties should not be treated as unitary actors, and that some parties may be less likely to be in government due to the fact that they use highly democratic decision-making procedures, or because they are highly factionalized. Another conclusion drawn here is that when explaining coalitions, we should consider that the history of interaction between parties matters and that parties are concerned with minimizing the transaction costs with forming a coalition. Many other theories are either backed up or discredited by the evidence.
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| 9. |
- Cornelissen, C, et al.
(författare)
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Global change and arctic ecosystems : is lichen decline a function of increases in vascular plant biomass?
- 2001
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 89:6, s. 984-994
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Tidskriftsartikel (refereegranskat)abstract
- 1 Macrolichens are important for the functioning and biodiversity of cold northern ecosystems and their reindeer-based cultures and economics. 2 We hypothesized that, in climatically milder parts of the Arctic, where ecosystems have relatively dense plant canopies, climate warming and/or increased nutrient availability leads to decline in macrolichen abundance as a function of increased abundance of vascular plants. In more open high-arctic or arctic-alpine plant communities such a relationship should be absent. To test this, we synthesized cross-continental arctic vegetation data from ecosystem manipulation experiments simulating mostly warming and increased nutrient availability, and compared these with similar data from natural environmental gradients. 3 Regressions between abundance or biomass of macrolichens and vascular plants were consistently negative across the subarctic and mid-arctic experimental studies. Such a pattern did not emerge in the coldest high-arctic or arctic-alpine sites. The slopes of the negative regressions increased across 10 sites as the climate became milder (as indicated by a simple climatic index) or the vegetation denser (greater site above-ground biomass). 4 Seven natural vegetation gradients in the lower-altitude sub- and mid-arctic zone confirmed the patterns seen in the experimental studies, showing consistent negative relationships between abundance of macrolichens and vascular plants. 5 We conclude that the data supported the hypothesis. Macrolichens in climatically milder arctic ecosystems may decline if and where global changes cause vascular plants to increase in abundance. 6 However, a refining of our findings is needed, for instance by integrating other abiotic and biotic effects such as reindeer grazing feedback on the balance between vascular plants and lichens.
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| 10. |
- Denison, Eva, et al.
(författare)
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Self-efficacy, fear avoidance, and pain intensity as predictors of disability in subacute and chronic musculoskeletal pain patients in primary health care
- 2004
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Ingår i: Pain. - : Ovid Technologies (Wolters Kluwer Health). - 0304-3959 .- 1872-6623. ; 111:3, s. 245-252
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the relations between disability, as measured by the Pain Disability Index (PDI) and self-efficacy, fear avoidance variables (kinesiophobia and catastrophizing), and pain intensity, using a prospective design. Two primary health care samples (n1=210; n2=161) of patients with subacute, chronic or recurring musculoskeletal pain completed sets of questionnaires at the beginning of a physiotherapy treatment period. Multiple hierarchial regression analyses showed that self-efficacy explained a considerably larger proportion of the variance in disability scores than the fear avoidance variables in the first sample. This finding was replicated in the second sample. Pain intensity explained a small, but significant proportion of the variance in disability scores in one sample only. Gender, age, and pain duration were not related to disability. These findings suggest that self-efficacy beliefs are more important determinants of disability than fear avoidance beliefs in primary health care patients with musculoskeletal pain. The findings also suggest that pain-related beliefs, such as self-efficacy and fear avoidance, in turn, are more important determinants of disability than pain intensity and pain duration in these patients.
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