| 14431. |
- Hintz, William D., et al.
(författare)
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Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length
- 2017
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Ingår i: Ecological Applications. - : John Wiley & Sons. - 1051-0761 .- 1939-5582. ; 27:3, s. 833-844
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Tidskriftsartikel (refereegranskat)abstract
- The application of road deicing salts in northern regions worldwide is changing the chemical environment of freshwater ecosystems. Chloride levels in many lakes, streams, and wetlands exceed the chronic and acute thresholds established by the United States and Canada for the protection of freshwater biota. Few studies have identified the impacts of deicing salts in stream and wetland communities and none have examined impacts in lake communities. We tested how relevant concentrations of road salt (15, 100, 250, 500, and 1000mgCl(-)/L) interacted with experimental communities containing two or three trophic levels (i.e., no fish vs. predatory fish). We hypothesized that road salt and fish would have a negative synergistic effect on zooplankton, which would then induce a trophic cascade. We tested this hypothesis in outdoor mesocosms containing filamentous algae, periphyton, phytoplankton, zooplankton, several macroinvertebrate species, and fish. We found that the presence of fish and high salt had a negative synergistic effect on the zooplankton community, which in turn caused an increase in phytoplankton. Contributing to the magnitude of this trophic cascade was a direct positive effect of high salinity on phytoplankton abundance. Cascading effects were limited with respect to impacts on the benthic food web. Periphyton and snail grazers were unaffected by the salt-induced trophic cascade, but the biomass of filamentous algae decreased as a result of competition with phytoplankton for light or nutrients. We also found direct negative effects of high salinity on the biomass of filamentous algae and amphipods (Hyalella azteca) and the mortality of banded mystery snails (Viviparus georgianus) and fingernail clams (Sphaerium simile). Clam mortality was dependent on the presence of fish, suggesting a non-consumptive interactive effect with salt. Our results indicate that globally increasing concentrations of road salt can alter community structure via both direct and indirect effects.
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| 14432. |
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| 14433. |
- Hirsh, Åsa, et al.
(författare)
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Emotional Labour of Swedish Principals in Low Socioeconomic Status Communities
- 2024
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Konferensbidrag (refereegranskat)abstract
- This paper examines principals’ emotional, and often invisible, work (Hochschild, 1983; cf. Wilkinson, 2021). Recent studies undertaken in a long-term network collaboration between school principals in low socioeconomic status Swedish communities and educational researchers, show how leadership is learned and shaped in and by context specific circumstances, entailing several challenges. The most prominent challenges are connected to a) high population mobility, b) comprehensive linguistic and cultural diversity, c) comprehensive knowledge diversity, and d) an intense problem complexity, i.e., a dense flow of extraordinary incidents in and around the schools (Hirsh et al., 2023). Although not explicitly elaborated on in these studies, the results also indicate that emotions are a prominent, albeit often unspoken, part of the principals' work. In this study, we re-analyse the same data that led to the above-mentioned findings, with specific interest directed towards finding discursive manifestations of emotional labour. Additionally, the new analysis is directed towards understanding and explaining principals’ emotional labour through a practice architectures lens. Principals’ leading is explored as a practice that consists of sayings, doings and relatings conditioning and conditioned by site-specific cultural-discursive, material-economic, and social-political arrangements (Kemmis et al., 2014). The empirical data underlying this study consists of five audio-recorded peer group dialogues between principals (N=20), conducted within the framework of the longitudinal R&D collaboration mentioned above. Our preliminary results show that some site-specific conditions in particular involve emotional labor: Work intensification, clearly connected to the context-related challenges that the previous study made visible and navigating the local policy context. We suggest that understanding emotional labor as an essential and demanding aspect of principals' work is necessary for the building of support structures around them, which in the long run can counter the impact of work intensification. Preliminary analysis also makes visible how the intertwined site-specific arrangements condition the principals' leading practices, and how they navigate and learn 'how to go on' based in the emotional labor. This suggests that emotional labor can be understood as conditions for educational leading practices, sometimes perceived as a burden for the individual but indeed also as important, site-based practice knowledge that gives principals’ work joy and meaning. Further, the methodological approach in the R&D collaboration, i.e., the peer-dialogues, seem to empower the principals and trigger agentive action in terms of proposing and initiating educational and workplace changes (cf. Hirsh et al, 2023).References:Hirsh, Å., Liljenberg, M., Jahnke, A., & Karlsson Perez Å. (2023). Far from the generalised norm: Recognising the interplay between contextual particularities and principals’ leadership in schools in low-socio-economic status communities. Educational Management Administration & Leadership, 1-18. DOI: 10.1177/17411432231187349Hochschild, A. R. (1983). The managed heart: Commercialization of human feeling. University of California Press.Kemmis, S., Wilkinson, J., Edwards-Groves, C., Hardy, I., Grootenboer, P., & Bristol, L. (2014). Changing practices, Changing education. Springer. Wilkinson, J. (2021). Educational leadership through a practice lens: Practice matters. Springer.
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| 14434. |
- Hirst, Clarissa, 1990-
(författare)
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On the Margins of a EU-Dominated Space : Three Approaches to Russia's Identity in the Baltic Sea Region
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Baltic Sea Region was the focal point of enormous geopolitical change in the late twentieth and early twenty-first centuries. Previously, the Soviet Union maintained a strong presence along the Baltic Sea coastline but as a result of its collapse, Germany’s reunification and successive European Union (EU) enlargements, the Baltic Sea Region is now an EU-dominated space. Regions of the Russian Federation now find themselves on the periphery. This paper hopes to offer insight into how we can understand Russia in the Baltic Sea Region today and serves as a starting point for empirical research into how Russia’s Baltic Sea identity is constituted in national and EU foreign policy. The paper is a critical review of the International Relations (IR) scholarship that has addressed Russia’s post-Cold War identity in the Baltic Sea Region. In particular, it addresses the following questions: what tensions and debates exist between different analytical approaches? How can this scholarship help us to understand Russia’s identity in the Baltic Sea Region at the present time? What significance do the discourses of ‘othering’ in the scholarship have for identity-building and inter-regional cooperation in the Baltic Sea Region? Constructivist and poststructuralist analyses dominated IR discussions on Russia in the Baltic Sea Region in the late 1990s and 2000s (see, for example: Joenniemi et al, 1997; Jæger, 2000; Joenniemi, 2000; Browning, 2001, 2003; Moisio, 2003; Aalto et al, 2003; Tassinari, 2003; Jakobsen-Obolenski, 2005). They critiqued the persisting Cold War dichotomy of East/West and offered solutions as to how this dichotomy could be overcome through emerging inclusive frameworks such as the Council of the Baltic Sea States and the EU’s Northern Dimension. Yet despite expressing optimism for inclusion in the future, these works continued to consider Russian regions as marginalised and not fully included in the region. Other perspectives have acknowledged the ability of Russian regions in the Baltic Sea Region to influence Russian and EU policy by considering the benefits of paradiplomacy for overcoming divisive politics (Joenniemi & Sergunin, 2014) or conceptualising the Kaliningrad Oblast as a marginal space that can exercise agency by simultaneously upholding and evading modernist understandings of territory (Browning & Joenniemi, 2004). Postcolonial perspectives potray Russia as an occupant of the ’middle ground’ between the civilised centre and the Orientalised periphery (Morozov, 2013). Such approaches suggest that Russian regions can potentially play an active role in identity politics instead of simply being relegated to the role of ’Other’. Yet such an active role for Russian regions remains largely in the realm of possibility rather than reality for these scholars. This paper considers the implications of IR discourses of ‘othering’ for identity-building and inter-regional cooperation in the Baltic Sea Region and consider whether the epistemic community has in fact reinscribed the exclusionary dynamics that it has sought to overcome.
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| 14435. |
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| 14436. |
- Hirvonen Grytzelius, Joakim, 1975-, et al.
(författare)
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Coverage dependence and surface atomic structure of Mn/Si(111)-√3×√3 studied by scanning tunneling microscopy and spectroscopy
- 2009
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - Washington : American Institute of Physics (AIP). - 1098-0121 .- 1550-235X. ; 80, s. 235324-1-235324-6
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Tidskriftsartikel (refereegranskat)abstract
- Thin manganese silicide films of different thicknesses on Si(111) have been studied in detail by low-energy electron diffraction (LEED), scanning tunneling microscopy, and scanning tunneling spectroscopy (STM/STS). Up to a Mn coverage of 3–4 monolayers (ML), island formation is favored. For higher Mn coverages up to 12 ML uniform film growth is found. The silicide film morphology at low coverages supports a layered Mn-Si film structure. The silicide surfaces displayed a √3×√3 LEED pattern. STM images recorded from the √3×√3 surfaces mostly show a hexagonal pattern but a honeycomb pattern has also been observed. A surface atomic structure based on chained Mn triangles is proposed. Our STM results are in good agreement with a recent theoretical model. The high-quality STS spectra recorded from the different surfaces show a clear metallic character at 1.5 ML and higher coverages. The filled-state features in the STS spectra at surfaces with 3–4 ML Mn coverages are similar to earlier published angle-resolved photoelectron spectroscopy data.
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| 14437. |
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| 14438. |
- Hirvonen Grytzelius, Joakim, 1975-, et al.
(författare)
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Mn5Ge3 film formation on Ge(111)c(2×8)
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - New York : American Physical Society. - 1098-0121 .- 1550-235X. ; 86:12, s. 125313-1-125313-7
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Tidskriftsartikel (refereegranskat)abstract
- Thin manganese germanide films with different thicknesses on Ge(111) have been studied in detail by low-energy electron diffraction (LEED), scanning tunneling microscopy, and core-level spectroscopy (CLS). Annealing of the deposited Mn on Ge(111)c(2×8) between 330-450 C resulted in well-ordered Mn5Ge3 surfaces as seen by intense 3×3 LEED spots. Up to a coverage of 24 monolayers (ML), island formation is favored. At a coverage of 32 ML a well ordered Mn5Ge3 film was found to fully cover the surface. High-resolution Ge 3d CLS spectra were recorded with photon energies between 50 and 110 eV at normal and 60 emission angles. In contrast to earlier results, three components have been used in the line-shape analysis to achieve a consistent fit over the energy and angular range. In addition, three components have been identified for the Mn 2p CLS spectra. The two major components fit well with a layered Mn germanide structure suggested in the literature.
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| 14439. |
- Hirvonen Grytzelius, Joakim, 1975-, et al.
(författare)
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Surface atomic and electronic structure of Mn5Ge3 on Ge(111)
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - New York : American Physical Society. - 1098-0121 .- 1550-235X. ; 84:19, s. 195306-1-195306-6
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Tidskriftsartikel (refereegranskat)abstract
- The atomic and electronic structure of the Mn5Ge3(001) surface grown on Ge(111) c(2×8) has been studied in detail by angle-resolved photoelectron spectroscopy (ARPES), scanning tunneling microscopy (STM), and scanning tunneling spectroscopy. ARPES spectra recorded from the Γ̅ -K̅ -M̅ and Γ̅ -M̅ -Γ̅ directions of the surface Brillouin zone show six surface-related features. The STM images recorded at biases higher/lower than ±0.4 V always show a honeycomb pattern with two bright protrusions in each unit cell. At lower biases, a hexagonal, intermediate transition, and a honeycomb pattern are observed. These can be explained as arising from Mn and Ge atoms in the sublayer arranged in triangular structures and Mn atoms in the top layer arranged in a honeycomb structure, respectively. The photoemission and STM data from the germanide surface are discussed and compared to earlier published theoretical, photoelectron spectroscopy, and scanning tunneling microscopy studies.
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| 14440. |
- Hirvonen Grytzelius, Joakim, 1975-, et al.
(författare)
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Surface electronic structure of Mn/Si(111)-√3×√3
- 2008
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - New York : American Institute of Physics. - 1098-0121 .- 1550-235X. ; 78:15, s. 155406-1-155406-6
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Tidskriftsartikel (refereegranskat)abstract
- The Mn/Si(111)-√3×√3 surface has been studied in detail by low energy electron diffraction (LEED), angle-resolved photoelectron spectroscopy (ARPES), and core-level photoelectron spectroscopy (CLS). Annealing of the deposited manganese resulted in a well-ordered surface as seen by intense √3×√3 LEED spots. ARPES spectra recorded in the Γ̅ -K̅ -M̅ direction of the √3×√3 surface Brillouin zone show five surface related features in the band gap while in the Γ̅ -M̅ -Γ̅ direction four surface features are observed. The high-resolution Si 2p CLS data were recorded at photon energies between 108–140 eV both at normal and 60° emission angle. The bulk component was identified from the bulk sensitive spectrum recorded at a photon energy of 108 eV. To achieve a consistent core-level fitting over the whole energy and angular range, five components were introduced in the line-shape analysis. The photoemission data from the √3×√3 surface have been discussed and compared with a recent theoretical model. The findings here support a layered Mn silicide film structure.
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