| 1. |
- Moles, Angela T, et al.
(författare)
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Correlations between physical and chemical defences in plants : tradeoffs, syndromes, or just many different ways to skin a herbivorous cat?
- 2013
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Ingår i: New Phytologist. - : Wiley-Blackwell. - 0028-646X .- 1469-8137. ; 198:1, s. 252-263
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Tidskriftsartikel (refereegranskat)abstract
- Most plant species have a range of traits that deter herbivores. However, understanding of how different defences are related to one another is surprisingly weak. Many authors argue that defence traits trade off against one another, while others argue that they form coordinated defence syndromes. We collected a dataset of unprecedented taxonomic and geographic scope (261 species spanning 80 families, from 75 sites across the globe) to investigate relationships among four chemical and six physical defences. Five of the 45 pairwise correlations between defence traits were significant and three of these were tradeoffs. The relationship between species' overall chemical and physical defence levels was marginally nonsignificant (P=0.08), and remained nonsignificant after accounting for phylogeny, growth form and abundance. Neither categorical principal component analysis (PCA) nor hierarchical cluster analysis supported the idea that species displayed defence syndromes. Our results do not support arguments for tradeoffs or for coordinated defence syndromes. Rather, plants display a range of combinations of defence traits. We suggest this lack of consistent defence syndromes may be adaptive, resulting from selective pressure to deploy a different combination of defences to coexisting species.
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| 2. |
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| 3. |
- Jaldemark, Jimmy, Docent, 1970-, et al.
(författare)
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Wearable technologies as a research tool for studying learning : The application of spy glasses in data collection of children's learning
- 2019. - 2
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Ingår i: Handbook of mobile teaching and learning. - : Springer. - 9789811327650
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Bokkapitel (refereegranskat)abstract
- This chapter discusses the potential that wearable technologies have for studying and understanding how people learn. In particular, the focus is on how spy glasses can be used as a tool for collecting data from educational situations. The chapter report from two different cases performed by the authors in which spy glasses were used, including considerations made from a methodological point of view. From the first case a conclusion is that spy-glass recording made it possible to closely follow teaching and learning during science labwork and find specific elements not found in video data from ordinary video cameras. The second case reports on valuable information about how the motivation for learning works in young children. Drawing further from these studies, the study elaborate on themes that arise as central to video research: ethics, technology and methodology as well as selection and analysis. The chapter discusses a transformation in how childhood is considered in relation to new technology. Here children are seen as more active and participatory in the shaping of their own childhoods. This can also result in developing new research methods in order to understand and visualise the child’s perspective, and using wearable technologies could certainly be one of these areas. In other words, it is a unique perspective when participants are co-creators of research studies. This implies important future work ahead, developing and applying wearable technologies for education and educational research.
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| 4. |
- Johansson, Helena, 1971-, et al.
(författare)
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Engineering students’ approach to studying mathematics and its influence on their achievement
- 2021
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Konferensbidrag (refereegranskat)abstract
- Previous research has addressed undergraduate students’ approaches to studying mathematics from various perspective, with differing results regarding influences on achievements. This study contributes to the fields understanding by examine if and how engineering students’ various approaches to studying mathematics, particularly a differential calculus course, affect their success on the course exam. Three questionnaires were distributed to the students and a logistic regression model showed that the habit to study regularly had a positive effect on exam results, whereas the strategy to imitate previous examples had a negative effect.
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| 5. |
- Moles, A. T., et al.
(författare)
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Putting plant resistance traits on the map : A test of the idea that plants are better defended at lower latitudes
- 2011
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 191:3, s. 777-788
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Tidskriftsartikel (refereegranskat)abstract
- It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes. • We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide. • Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in high-latitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics. • Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments. © 2011 New Phytologist Trust.
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| 6. |
- Sandström, Jennie
(författare)
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Phytoplankton response to a changing climate in lakes in northern Sweden
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In a climate change perspective, increased air temperatures are already a reality and are expected to increase even more in the future, especially in areas at high latitudes. The present thesis therefore addresses the influence of climate change on the physical properties and the phytoplankton communities of typical small and oligotrophic lakes in northern Sweden (62-64˚N). In the first part of the study, we found a significant trend (10 lakes from 1916 to 2010) of ice break-ups occurring increasingly earlier. The timing of ice break-up was strongly influenced by the April air temperature indicating that expected increases in air temperature in the future will also result in an earlier ice break-up. We also used concentrations of chlorophyll a (chl a) as estimations of phytoplankton biomass and discovered a positive relationship between surface water temperature and concentrations of chl a in Lake Remmaren (from 1991 to 2008). The second part of the thesis focuses on climatic conditions and cyanobacteria abundance in three small, oligotrophic lakes in northern Sweden; Lake Remmaren, Lake S. Bergsjön and Lake Gransjön. The concentration and relative abundance of cyanobacteria differ between 2011 and 2012, with different climatic conditions. The "warm" year of 2011 had higher concentrations and relative abundance of cyanobacteria than the "cold" year of 2012. Trends in increasing surface water temperatures as well as increasing abundance of cyanobacteria in August were found in Lake Remmaren (from 1988 to 2011). The direct or indirect effects of warming had a positive effect on the cyanobacteria abundance, since nutrients (Tot N and Tot P) did not display an increasing trend in Lake Remmaren. An analysis on the composition of phytoplankton species in Lake Remmaren, Lake S. Bergsjön and Lake Gransjön revealed that the cyanobacteria Merismopedia sp. was more common in 2011 than 2012. If different cyanobacteria become more common in oligotrophic lakes in the future, the functioning of lake ecosystems may be impacted. Small zooplankton eats small phytoplankton and if smaller phytoplankton species, e.g. cyanobacteria, increase at the expense of other phytoplankton groups, an extra step in the food chain might be added. Less energy might be transferred to the upper levels because many cyanobacteria contain toxic compounds and are less edible than other phytoplankton groups. An increase of toxic containing cyanobacteria in lakes can also make lakes less attractive for recreational purposes in the future.
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| 8. |
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| 9. |
- von Zeipel, Hugo, et al.
(författare)
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Fruit removal in the forest herb Actaea spicata depends on local context of fruits sharing the same dispersers
- 2007
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 168:6, s. 855-860
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Tidskriftsartikel (refereegranskat)abstract
- Heterospecific effects from neighboring plants on fruit removal are rarely examined. In this study we recorded removal of fruits of four species from experimental plots. The main study species, the forest herb Actaea spicata, has berries attractive to rodents. We tested for effects from a larger-scale context (plant abundance) and a smaller scale (number of fruits aggregated including several species with fleshy as well as dry fruits). Fruit removal varied among sites. Fleshy-fruited species removal was correlated within sites. Fruit removal was higher within than outside Actaea populations but was unrelated to plant abundances among existing populations. The small-scale context treatment yielded clear results. Removal of Actaea fruits was higher from large aggregations of fruits, and it was the number of fruits rather than species identity that affected removal. Presence of both fleshy and dry fruits increased removal. This study provides experimental evidence of heterospecific effects on fruit removal, and we conclude that the species included in the study attract the same dispersers and that the small-scale biotic context is important. We suggest the existence of dispersal hot spots related to the fruit presence overlaid by an unexplained variation among sites.
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| 10. |
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| 11. |
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| 12. |
- von Zeipel, Hugo
(författare)
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Illustrations in Science Education : An Investigation of Young Pupils Using Explanatory Pictures of Electrical Currents
- 2015
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Ingår i: XVI INTERNATIONAL ORGANISATION FOR SCIENCE AND TECHNOLOGY EDUCATION SYMPOSIUM (IOSTE BORNEO 2014). - : Elsevier BV. ; , s. 204-210
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Konferensbidrag (refereegranskat)abstract
- This study is part of a project regarding explanatory illustrations in science education. Research questions here concern how pupils use and make meaning from illustrations in a science textbook. Electricity was chosen as the subject. Video data was collected in 8 sessions, each with a pair of pupils, 10-11 years of age in one school in Sweden. Communication within the pairs and with the interviewer was analyzed. The children also drew a picture of a battery and explained its function using this drawing. The most striking result was an almost complete lack of transparency for the scientific information in the illustrations. Regardless of previous knowledge, pupils were almost never able to collect new information on their own or together with their peer. As long as the visual information matched previous knowledge they could explain the content, but as the complexity increased, they were lost. They then either expressed their incomprehension or carried on to argue for evident misconceptions, not realizing that the illustrations were contradicting them. Together with the interviewer, pupils could eventually identify central scientific messages and where their previous understanding was challenged. One conclusion is that scientific illustrations can drive scientific in-depth discussion. However, the main conclusion is that pupils are not trained to interpret multimodal information themselves and that teachers and textbook authors therefore risk overestimating pupils de-coding abilities. (C) 2014 The Authors. Published by Elsevier Ltd.
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| 13. |
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| 14. |
- von Zeipel, Hugo, et al.
(författare)
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The Science labwork situation and opportunities for learning – Teacher and student perspectives
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Labwork in science education has been questioned with respect to its contribution to learning. This paper reports on critical factors to enhance students’ meaning making during labwork in six different Swedish schools. Using Spy-glass cameras we were able to collect close-up video data from student talk and activities. Student focus varied between schools and student groups, on most occasion a majority of time was spent focusing clearly outside anything related to the subject. Teachers’ introductions were categorized according to their main focus (scientific ideas, laboratory skills or knowledge of scientific inquiries) and school-related students’ negotiations were analyzed using the same categories. There was no clear-cut relationship between the focus of teacher introductions and the nature of the school-related student negotiations. Overall, teacher introductions most often focused on the scientific ideas. However, student negotiations were dominated by the laboratory skills category, followed by scientific ideas. Negotiations concerning knowledge of scientific inquiry were rare. Small variations among groups suggests that students had similar experiences of what was expected from them in the labwork situation. We found a connection between whether the scientific ideas had been previously processed and the likelihood that students discussions would focus on the scientific ideas. There was a range in the type of tasks given to the students in connection with the labwork. We found that both open discussions about scientific topics as well as limited activities such as simply filling in a form could potentially generate scientific discussions. However, the combination of previously unprocessed scientific content and openly formulated tasks was never successful. We conclude that several factors affect student focus and that the labwork situation remains questionable as learning situations as long as all these factors are not entirely appreciated by teachers.
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| 15. |
- von Zeipel, Hugo, 1973-
(författare)
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The spatial and temporal dynamics of plant-animal interactions in the forest herb Actaea spicata
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Landscape effects on species performance currently receives much attention. Habitat loss and fragmentation are considered major threats to species diversity. Deciduous forests in southern Sweden are previous wooded pastures that have become species-rich communities appearing as islands in agricultural landscapes, varying in species composition. Actaea spicata is a long-lived plant occurring in these forests. In 150 populations in a 10-km2 area, I studied pre-dispersal seed predation, seed dispersal and pollination. I investigated spatio-temporal dynamics of a tritrophic system including Actaea, a specialist seed predator, Eupithecia immundata, and its parasitoids. In addition, effects of biotic context on rodent fruit dispersal and effects of flowering time and flower number on seed set, seed predation and parasitization were studied. Insect incidences of both trophic levels were related to resource population size and small Eupithecia populations were maintained by the rescue effect. There was a unimodal relationship between seed predation and plant population size. Seed predator populations frequently went extinct in small plant populations, resulting in low average seed predation. Parasitoids were present in large plant populations but did not affect seed predator density. Seed predators aggregated at edges, relaxing seed predation in patch interiors. Flowering phenology was unrelated to seed set and insect incidence. A higher flower number did not influence seed predation but was associated with higher seed set and a tendency for a higher parasitization rate. In the study on fruit dispersal more fruits were removed inside than outside populations. Within plant populations more fruits were removed from large aggregations. Overall, this thesis underlines the importance of plant-animal interactions during different phases of the life cycle. The spatial configuration of host plants plays an important role for the outcome of plant-animal interactions and trophic cascades.
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| 16. |
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| 17. |
- Åberg-Bengtsson, Lisbeth, et al.
(författare)
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Can we take young pupils’ understanding of Illustrations for granted? Investigating multi-modally presented learning-contents in school science and mathematics
- 2011
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Konferensbidrag (refereegranskat)abstract
- New ways of presenting information have affected both contemporary society and education. School textbooks and other teaching aids for young pupils nowadays typically include, or sometimes entirely build on, illustrations and visual information. During the latest decades our view on literacy has shifted towards also comprising, as a necessity, visual and multimodal literacies Kress (2003). When using visual information in education, the transparency of pictures and models is often regarded as unproblematic. However, transparency is not an innate quality of illustrations and cannot be taken for granted (Pintó & Ametller, 2002). On the contrary, visual information is always coded and interpretations are always related to culture and context, so we must always ask what aspects of illustrations are easily understood by our young pupils’ and what aspects may be stumbling blocks for them.
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| 18. |
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| 19. |
- Åberg-Bengtsson, Lisbeth, et al.
(författare)
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När Agnes fick va solen så fattade man ju precis : Om illustrationer i undervisning av yngre elever
- 2014
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Ingår i: Resultatdialog. - Stockholm : Vetenskapsrådet. - 9789173072472 ; , s. 246-254
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Att göra adekvata tolkningar av bilder och modeller kan vara verkliga stötestenar för många barn. Särskilt besvärligt förefaller det vara att tolka bilder av processer och förlopp i tryckta läromedel. Även enk-lare bilder och vanliga symboler kan dock leda till icke avsedda tolkningar. Barnen i studien föreföll i många fall betrakta illustrationerna som enbart dekoration och förbigick dem ofta om de inte direkt uppmärksammades på dem. Å andra sidan kunde illustrationer också, särskilt sådana som visade på extremer av något slag, väcka förundran och intresse.
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