4,325 research outputs found
Replication Data for: Issue salience, position and framing of EU enlargement in European political party manifestos for the 2019 and 2024 European elections
No full text17 European political party manifestos for the 2019 and 2024 European Parliament Elections unitized into quasi-sentences based on the methodological approach of the (Euro-)manifesto project (https://manifesto project.wzb.eu/information/documents/handbooks). Analysis of issue salience, position, and framing of EU enlargement per European political party. Includes all Europarties that are recognized by the Authority for European Political Parties and European Political Foundations (APPF). This data is part of a work package within PhD project Lien Jansen: 'Changing MEP Behaviour Towards EU enlargement with the Western Balkans: the Implications of the Russian Invasion in Ukraine (2019-2024)' and related to the following publication: Jansen, L., Hecke, S. V., & D’Haeninck, E. (2025). Evident but implicit? Europarties’ role in geo-politicising EU enlargement and the 2022 Russian invasion in Ukraine. European Politics and Society, 1–17. https://doi.org/10.1080/23745118.2025.259516
JANSEN, Martha Mabel Inventory of documents
No full textCOVERAGE 1915-1960; 192 Files; 4,33 Metres.
AUDIO CASSETTES IN ARCA COLLECTION = 6Private papers of M.M. Jansen, founder member of the Afrikaanse Taalbond in Natal and the first woman to become a member of the Academy for Language, Literature and Art. She was editor for the woman's section of Die Landbou Weekblad and columnist for Die Afrikaner [Natal] [1924], Deputy Leader of the National Party Natal [1933] and a founder member of the FAK and the Voortrekkerbeweging. Author of several publications
From systematic to ecological wood anatomy and finally plant hydraulics: are we making progress in understanding xylem evolution?
No full textOlson (2014; in this issue of New Phytologist, pp. 7–11) provides a valid criticism of our recent commentary (Nardini & Jansen, 2013).Although we see no controversy surrounding Bailey’s functional and evolutionary ideas, we would like to pay attention in this Letter to two related concerns: (1) the integration of experimental data from the field of plant hydraulics into traditional, comparative wood anatomy; and (2) the reversibility of evolutionary transitions between perforation plate types that form a continuum
Aluminium accumulation in tropical and temperate plants: ecological, physiological and evolutionary aspects
No full textThe goal of the first chapter of this thesis was to quantitatively evaluate the Al concentration in various plant tissues of Symplocos species natively growing in their natural habitats in Indonesian montane rainforests. My main goal was to investigate the natural concentration of Al in different plant organs of Symplocos species in order to improve sustainable use by weaving communities. Furthermore, this study contributes to our understanding of the intraspecific and within-tree variation of Al accumulation, which was also studied with respect to soil characteristics.
The second chapter includes a hydroponic setup in order to investigate the Al behaviour of Symplocos paniculata. I tested the effect of Al on seedlings and saplings of S. paniculata. The goal was to determine whether this temperate species a) would be able to accumulate Al in its above ground plant organs similar to tropical sister species, and b) would show a beneficial effect on its growth when Al was added to the nutrient solution.
The third chapter, unlike chapters one and two, focuses on ferns and lycophytes instead of angiosperm plant species. While the evolution and phylogeny of Al accumulation was studied in detail for angiosperms (Jansen et al. 2000, 2002, 2004), this trait remains poorly explored in pteridophytes. By compiling a global dataset from literature and novel data, I aimed to explore the phylogenetic signals associated with Al accumulation in fern and lycophyte species
2017_implementation_of_extended_examination_duration_suppl_1 – Supplemental material for The Implementation of Extended Examination Duration for Students With ADHD in Higher Education
No full textSupplemental material, 2017_implementation_of_extended_examination_duration_suppl_1 for The Implementation of Extended Examination Duration for Students With ADHD in Higher Education by Dorien Jansen, Katja Petry, Steven W. Evans, Ilse Noens and Dieter Baeyens in Journal of Attention Disorders</p
2017_implementation_of_extended_examination_duration_suppl_2 – Supplemental material for The Implementation of Extended Examination Duration for Students With ADHD in Higher Education
No full textSupplemental material, 2017_implementation_of_extended_examination_duration_suppl_2 for The Implementation of Extended Examination Duration for Students With ADHD in Higher Education by Dorien Jansen, Katja Petry, Steven W. Evans, Ilse Noens and Dieter Baeyens in Journal of Attention Disorders</p
The structure and function of ray and axial parenchyma in woody seed plants
No full textParenchyma represents an important interconnected three-dimensional living tissue in secondary xylem of woody seed plants, with functions ranging from transport and storage to defence and biomechanics, along with less understood functions, such as in long-distance water transport. We lack a large-scale analysis of ecological traits associated with ray parenchyma (RP) and axial parenchyma (AP). Here, we explore global trends in the AP and RP fraction per cross-sectional wood area based on literature data, including 1,727 entries from three major biomes (temperate, subtropical and tropical). We found a 29-fold variation in RAP fraction, where temperature was found to be the biggest driver of RAP (RP+AP) levels, followed by precipitation, with the latter showing a significant but negative relationship with RAP, demonstrating an increase in RAP towards drier sites. RAP fractions were higher in tropical than temperate angiosperm trees (21.1 vs 36.2 %), respectively, where AP was found to be the most versatile parenchyma type resulting in the sharp rise of RAP in the tropics, while RP remained relatively constant. Succulents (including pachycauls) and lianas were found to have higher RAP fractions than non-succulent angiosperm trees and conifers, with the latter having the lowest RAP fractions, as expected. The observed trends were interpreted with respect to the various functions of RAP in plants. We tested one of the hypotheses arising from the global analysis, and found RAP or/and ‘living’ fibres levels in a range of temperate species to be the uppermost limit for NSC storage, demonstrating that species with higher RAP and/or living fibre fractions in the selected species have a greater capacity for carbon storage: the same trend was not found for lowland tropical species. Also, starch accumulation was equally distributed across both RP and AP (including contact cells) in most of the temperate species analysed at the onset of winter, a trend not observed in the tropical species, where, although evident, the distribution was far sparser, with the exception of Brosimum sp. In summary, our results form a strong basis in which to better understand the functional implications of the great anatomical variability in wood parenchyma
The risk of embolism formation in relation to summer drought, xylem anatomy, and sap chemistry of temperate angiosperm trees
No full textIn this disseration, three chapters are included, with each chapter focusing on different aspects of water transport in plant xylem. In Chapter 1, the risks of embolism formation in both stem and leaf xylem for temperate angiosperm trees during summer drought, and difference in xylem embolism resistance between leaves and stems were studied. The results suggested that stem and leaf xylem of temperate angiosperm tress in Ulm experienced minimal embolism formation during the moderate summer drought in 2019 and 2020; Leaf xylem of the ten species studied is not more vulnerable to embolism than stem xylem, which is further supported by similar intervessel pit membrane thickness in both organs. In Chapter 2, I examined how proximity of pre-existing gas embolism and vessel segmentation would influence embolism spreading. By comparing xylem embolism resistance between deatached leaves and leaves attached to branches, and between intact leaves and leaves with cut minor veins., the results concludes that embolism spreading between intact vessels may not only depend on a certain pressure threshold between the sap-filled and gas-filed conduits, but also on the proximity to gas source. In Chapter 3, I focused on the link of nanoparticle and lipid concentration of xylem sap in different seasons, and their relation with xylem anatomy. I found that nanoparticles and polar lipids are artefact-free components in xylem sap, and mostly do not cross intervessel pit membranes. Their concentrations are largely affected by vessel anatomy among different species. These studies provided important information for helping us understand the risk of embolism formation of temperate angiosperm tress from different aspects
Gegevens en beschouwingen over scheepshellingen en dokken (colleges prof. Jansen)
No full textOverzicht droogdokken en scheepshellingen. Jaartal geschatHydraulic EngineeringCivil Engineering and Geoscience
City landscape usage on dissolved organic matter along Willband Creek, Abbotsford, BC
No full textDissolved organic matter (DOM) comes from the partial decomposition of organic material and from water-soluble particles released by living organisms. It is an important piece of the aquatic food chain which plays a role in ecosystem productivity, nutrient cycling, UV light penetration, and heavy metal transport (Baines & Pace, 1991, Downing et al., 2009, Jansen, Kalbitz & McDowell, 2014, McKnight et al., 2001, Saraceno et al., 2009, Stedmon, Markager, & Bro, 2003, Williams et al., 2013,Wright & Reddy, 2009). DOM is a major contributor to the forming processes of soil as well as feeding microbial metabolism in aquatic environments, and relies on the hydrologic regimes for transport through soils to aquatic systems. Various anthropogenic landscapes can potentially have a large influence on the ecosystem dynamics of DOM, both directly (e.g., agriculture) and indirectly (e.g., impervious surfaces) (Baines & Pace, 1991, Jansen, Kalbitz, & McDowell, 2014, Saraceno et al., 2009, Williams et al., 2013, Wright & Reddy, 2009). Willband Creek is located in Abbotsford, BC, Canada (figure 1). It drains an area over 69 km2 by the time it joins the Fraser River at Matsqui Slough and is an important salmon bearing watershed (DFO, 1999). The creek itself begins from a groundwater fed lake in a large urban park near the centre of town before passing through residential, park/natural, industrial, and agricultural land before exiting into the Fraser River, and is joined by side tributaries that come off of the multi-usage Sumas Mountain and passing through agriculture land (figure 2). As part of a larger project, the purpose of this study is to attempt to understand how the various cityscape uses affect the movement and concentration of DOM within a dynamic aquatic environment.This poster won the Vice-Presidents, Students Award (2019). Faculty advisors: Sharon Gillies and Steven Marsh, Department of Biology
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