9,724 research outputs found
Högskolepedagogik. Att vara professionell som lärare i högskolan
No full textSven B Eriksson recenserar:Högskolepedagogik. Att vara professionell som lärare i högskolan, av Martin Stigmar (red.), Liber, 2009</p
The Sense of Coherence: Measurement Issues
No full textIn this chapter, measurement issues are addressed concerning Aaron Antonovsky’s original sense of coherence (SOC) questionnaires of 29 items and of 13 items, as well as several modified translations applicable to the individual, the family, the organization, and the community levels. Validity (face, construct, consensual, criterion, predictive) and reliability issues (test-retest, internal consistency) of the scales are discussed. Criticism of the original scales is deliberated
Male and female Trybliographa rapae (Hymenoptera: Figitidae) behavioural responses to food plant, infested host plant and combined volatiles
No full textParasitoids reach maximum reproductive success when responding to plant stimuli associated with food and host. We investigated the attraction of the parasitic wasp Trybliographa rapae Westwood (Hymenoptera: Figitidae) to volatiles emitted from plants infested by the cabbage root fly Delia radicum L. (Diptera: Anthomyiidae), as well as to volatiles from a nectar food plant. Behavioural choice tests showed that male parasitoids were not attracted to any volatiles from plants infested by D. radicum or from nectar plants, while females showed clear attraction to both volatile sources. Newly emerged females preferred combined volatiles of host and food plants over those from only the host plant, whereas older females showed no differences in attraction. This suggests that intercropping attractive flowers with host plants could potentially be used to recruit newly emerged parasitoids from surrounding fields while older parasitoids invest more energy in host allocation than in additional food search. Volatiles from a whole infested plant were preferred over those emitted from separated above- and belowground parts from infested plants, indicating that female parasitoids recognize a synergistic effect from plant volatiles. It is important to consider the availability of both energy and host resources for parasitoids when designing an eco-compatible management of a vegetable crop system
Atom chip for BEC interferometry
No full textWe have fabricated and tested an atom chip that operates as a matter wave interferometer. In this communication we describe the fabrication of the chip by ion-beam milling of gold evaporated onto a silicon substrate. We present data on the quality of the wires, on the current density that can be reached in the wires and on the smoothness of the magnetic traps that are formed. We demonstrate the operation of the interferometer, showing that we can coherently split and recombine a Bose–Einstein condensate with good phase stability
Effects of strain on ferroelectric polarization and magnetism in orthorhombic HoMnO3
No full textWe explore how the ferroelectric polarization of antiferromagnetic E-type orthorhombic HoMnO3 can be increased, by investigating the effects of in-plane strain on both the magnetic properties and the ferroelectric polarization, using combined density functional theory calculations and a model Hamiltonian technique. Our results show that the net polarization is strongly enhanced under compressive strain, due to an increase of the electronic contribution to the polarization. In contrast, the ionic contribution is found to decrease. We identify the electron-lattice coupling, due to Jahn-Teller (JT) distortions, and its response to strain, to be responsible for the observed behavior. The JT-induced orbital ordering of occupied Mn-e(g)(1) electrons in alternating 3x(2)-r(2)/3y(2)-r(2) orbital states in the unstrained structure, changes under in-plane compressive strain to a mixture with x(2)-z(2)/y(2)-Z(2) states. The asymmetric hopping of e(g) electrons between Mn ions along zigzag spin chains (typical of the AFM-E spin configuration) is therefore enhanced under strain, explaining the large value of the polarization. Using a degenerate double-exchange model including electron-phonon interaction, we reproduce the change in the orbital ordering pattern. In this picture, the orbital ordering change is related to a change of the Berry phase of the e(g) electrons. This causes an increase of the electronic contribution to the polarization. DOI: 10.1103/PhysRevB.87.014403 RI Barone, Paolo/C-8918-201
Impact of structural habitat modifications in coastal temperate systems on fish recruitment: A systematic review
No full textBackground: Shallow nearshore marine ecosystems are changing at an increasing rate due to a range of human activities such as urbanisation and commercial development. As a result, an increasing number of structural modifications occur in coastal nursery and spawning habitats of fish. Concomitant to this increase, there have been declines in many coastal fish populations and changes in the composition of fish communities. As requested by Swedish stakeholders, this review aimed to synthesise scientific evidence of the impact on fish recruitment of structural modifications in temperate coastal areas. Methods: We searched for peer-reviewed and grey literature on such impacts in English, Dutch, Danish, Finnish, German, Swedish and Spanish. Searches were performed in bibliographic databases, specialist websites, bibliographies of review articles. We also contacted stakeholder to find relevant literature. Eligible studies included small- and large-scale field studies in marine systems and large lakes (> 10,000 km(2)) in temperate regions of the Northern and Southern Hemispheres. Included replicated comparisons of fish recruitment between altered and unaltered control areas, comparisons before and after an alteration, or both. Relevant outcomes (response variables) included measures of recruitment defined as abundance of juvenile fish in coastal habitats. All fish species were considered. Articles were screened for eligibility by title, abstract and full text. Eligible studies were critically appraised based on their external and internal validity. From each eligible study of sufficient validity, we extracted information on study design, measured outcomes, exposure, type of comparator, effect modifiers and study findings. Study findings were synthesised narratively. Results: We searched for eligible studies in 15 databases, 24 specialist websites, Google Scholar, and bibliographies of 11 review articles. The review finally included 37 studies that were eligible and of sufficient validity to be considered for final synthesis. Most studies (23 of 37) were from the Northern Hemisphere. Studies varied in design, spatial resolution, target fish species, and type of structural habitat change. This high level of variation did not allow for a quantitative synthesis and prevented us from drawing general conclusions on the impact of structures or structural modifications on fish recruitment. In this review we provide a narrative synthesis of the evidence base and classify eligible studies into six categories (based on type of exposure and comparator). The categories are as follows: the impacts on fish recruitment of: (1) artificial structures in coastal areas, (2) structures designed as fish attractors, (3) large scale urban sprawl, (4) 'novel' habitats, (5) habitat loss, and (6) restoration. Conclusions: This review revealed a very limited evidence base for how structural modifications and marine urban sprawl can affect fish recruitment. Thus, there is a substantial mismatch between stakeholder needs and research evidence. Further, the impact and ecological performance of artificial structures depend both on context and species. Clearly, there is a need for more research on the subject, especially on long-term consequences at larger spatial scales
Lamin and b-tubulin fragmentation precede chromatin degradation in glutamate-induced neuronal apoptosis
No full textComparison of nectar use and preference in the parasitoid Trybliographa rapae (Hymenoptera: Figitidae) and its host, the cabbage root fly, Delia radicum (Diptera. Anthomyiidae)
No full textThis study investigated differences in flower preferences between the parasitoid Trybliographa rapae Westwood (Hymenoptera: Figitidae) and its host, the economically important pest of cruciferous crops, the cabbage root fly, Delia radicum L. (Diptera: Anthomyiidae). The data obtained were used to suggest selective food plants in conservation biological control programmes for control of D. radicum. The attraction of both insect species to floral odours emitted from nine different plant species, their ability to access nectar from four of these species and the effect of the most promising plant species on insect longevity were determined.
Naive T. rapae females were significantly attracted to flower odours from Fagopyrum esculentum Moench. (Polygonaceae) and repelled by Coriandrum sativum L. (Apiaceae) and Borago officinalis L. (Boraginaceae). In addition, T. rapae gained weight when exposed to F. esculentum, Anethum graveolens L. (Apiaceae) and Lobularia maritima Desv. (Brassicaceae). In contrast, naive D. radicum females showed attraction to most of the flowers. The longevity of both T. rapae and D. radicum increased significantly when they were provided with flowering A. graveolens and F. esculentum.
In addition to the laboratory studies, a semi-field experiment was made to study the impact of flowering F. esculentum on the ability of T. rapae to parasitize D. radicum larvae. Significantly more larvae were parasitized in cages where a floral resource was present. The findings are discussed in the context of a Brassica agroecosystem
Drepanoistodus iommii Rasmussen & Eriksson & Lindskog 2021, sp. nov.
No full textDrepanoistodus iommii sp. nov. urn:lsid:zoobank.org:act: 0E2832F5-672E-4FAE-B5A5-CBA5DE1A4824 Fig. 6E–H partim Drepanoistodus aff. basiovalis – Mellgren & Eriksson 2010: fig. 7m (only). Drepanoistodus cf. basiovalis – Mellgren et al. 2012: fig. 5e. Diagnosis A Drepanoistodus species characterised by a geniculate element with distinct keels on the cusp and upper margin of the base; a straight basal margin; a straight to weakly rounded (convex) anterior margin and cusp which is approximately twice the length of the upper margin of the base. Etymology Named in honour of legendary guitarist Tony Iommi, founding member of heavy metal band Black Sabbath. Material examined Ten geniculate elements including eight from the Lynna section. Holotype, geniculate element (Fig. 6E–F); LO 12479T. Type locality River bank near the mouth of Lynna River, village of Kolchanovo, St. Petersburg region, Russia (60°00′39″ N, 32°33′49″ E). Type stratum Approximately 10 cm above the local base of the Lynna Formation, sample LY 12-16. Lower part of the Lenodus variabilis Zone. Description Cusp reclined and straight with distinct keels developed on the anterior (upper) and posterior (lower) margins. A median, longitudinal carina is developed on both sides of the cusp, but it is especially distinct on the inner side. Base is characterised by a straight or almost straight basal margin and a distinct keel on the upper margin. Whereas this keel is slightly convex, the upper margin below the keel is straight. Anterior margin is usually straight or weakly rounded (convex), but occasionally, it is strongly rounded. Angle A between the cusp and upper margin of the base is ca 30° (mean) with a standard deviation at 4.2 (Fig. 5B), and the mean ratio between length of the free upper margin (b) and the free cusp (c) is 0.54 (standard deviation 0.10). Remarks In the PCA plot (Fig. 4), the population of D. iommii sp. nov. is situated in the upper right corner, separated from the D. basiovalis population as well as the other two new species populations described herein. The vectors in the biplot demonstrate that this is mainly due to the straight basal margin, the relatively long upper margin (high b/c values), and the usually straight anterior margin in D. iommii sp. nov., which is in accordance with the characters diagnosed above. The hypothesis that the population of D. iommii sp. nov. is morphologically different from the D. basiovalis population is supported by the PERMANOVA test (Fig. 5A), which shows that the probability that the two populations are the same is exceedingly low (p (same) = 1.00E- 04). Occurrence The L. antivariabilis Zone (sample LY12-9) to the L. variabilis Zone (sample LY12-21b). Outside the St. Petersburg region, D. iommii sp. nov. has been recorded from the L. variabilis Zone at the Hällekis quarry in Västergötland, Sweden (Mellgren & Eriksson 2010; referred to as D. aff. basiovalis) and from the L. pseudoplanus Zone or E. suecicus Zone of the island Osmussaar, Estonia (Mellgren et al. 2012; reported as D. cf. basiovalis).Published as part of Rasmussen, Jan Audun, Eriksson, Mats E. & Lindskog, Anders, 2021, Middle Ordovician Drepanoistodus (Vertebrata, Conodonta) from Baltica, with description of three new species, pp. 106-134 in European Journal of Taxonomy 774 on pages 119-120, DOI: 10.5852/ejt.2021.774.1533, http://zenodo.org/record/555714
Messenger RNA of G-proteins alpha subunit in rat brown adipose tissue.
No full textThe present study was addressed to quantify the steady-state mRNA levels for the alpha subunit of stimulatory (Gs) and inhibitory (Gi-1 and Gi-2) G-proteins in brown (interscapular) male rat adipose tissue (n = 6 rats). The quantification of specific mRNA, estimated using a solution hybridization RNAse protection assay, showed that the amounts of G alpha i-1, G alpha i-2 and G alpha s mRNA were 0.88 +/- 0.28 amol/microgram DNA, 76 +/- 4 amol/micrograms DNA and 460 +/- 16 amol/micrograms DNA, respectively. When the amounts of G alpha i-1 and G alpha i-2 and G alpha s mRNA in brown adipose tissue were compared with those in epididymal white adipose tissue (obtained from the same rats), G alpha i-1 and G alpha i-2 mRNA levels were very similar between brown and white adipose tissue, whereas the level of G alpha s mRNA was significantly higher in brown than in white fat tissue (P < 0.001). In conclusion, the present study shows the steady-state levels of mRNA for the alpha subunit of Gs, Gi-1 and Gi-2 in rat brown fat and suggests that the quantity of G alpha s mRNA is higher in brown than in white adipose tissue. Further studies are needed to explain the possible physiological importance of these findings
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