The forest as a taskscape: seeing through the good forest owner’s eyes

This article is a reanalysis of interviews conducted in 2006 and 2009 with forest owners and their families. It gives a complementary interpretation of the forest owners’ decisions to replant spruce despite strong criticism from the public and from experts. The interviewees’ visual conception of the forest landscape and how they relate to it through their forestry practices is analysed. The results show that the forest owners prefer landscapes that are clean and tidy, showing characteristics indicative of forestry skills. At the same time they remain sensitive to the existence of other value systems among the public. The forest owners’ way of looking at the forest was characterized by the fact that they worked with the landscape; for them the forest is not only a symbolic project linked to identity, but also a taskscape, an imprint of performed work. In the discussion, the forest owners’ aesthetic value system is discussed and a supplementary answer is given to why forest owners refused to heed warnings about the replanting of spruce, a question that earlier studies generally attributed to forest owners’ wish to avoid short-term economic risks

Plant performance in living wall systems in the Scandinavian climate

The concept of green façades is not new (Koehler, 2008), but their reintroduction may offer benefits in the current urban design, which is increasingly focused on urban densification. The benefits of vertical greening include noise abatement (Van Renterghem et al., 2013), filtering of airborne dust and pollutants (Ottele et al., 2010 and Sternberg et al., 2010), and reduction of temperature close to the area of vertical greening (Onishi et al., 2010, Wong et al., 2010 and Perini et al., 2011a). The thermal aspects of vertical greening are, however, still under debate (Hunter et al., 2014). One particular type of green façade is living wall systems, which are vertical greening systems where plants are grown without the need for contact with the ground (Koehler, 2008, Francis and Lorimer, 2011 and Perini et al., 2011b). Living wall systems can be seen as an alternative way of introducing urban greening in dense urban areas in the same way as e.g. green roofs, which have shown to support a high arthropod diversity (Rumble and Gange, 2013 and Madre et al., 2013). Like plants on green roofs (Emilsson and Rolf, 2005 and Emilsson, 2008), plants in living wall systems must be able to cope with extreme conditions, such as high irradiation, considerable differences in temperature and possible water shortage. The main aim of this study was to determine whether it is possible to grow perennial plants in living wall systems in the Scandinavian climate and we hypothesized that perennial plants could survive in, and would be a viable option for, living wall systems in the Scandinavian climate

Viability of pico- and nanophytoplankton in the Baltic Sea during spring

Phytoplankton cell death is an important process in marine food webs, but the viability of natural phytoplankton communities remains unexplored in many ecosystems. In this study, we measured the viability of natural pico- and nanophytoplankton communities in the central and southern parts of the Baltic Sea (55°21′ N, 17°06′ E–60°18′ N, 19°14′ E) during spring (4th–15th April 2016) to assess differences among phytoplankton groups and the potential relationship between cell death and temperature, and inorganic nutrient availability. Cell viability was determined by SYTOX Green cell staining and flow cytometry at a total of 27 stations representing differing hydrographic regimes. Three general groups of phytoplankton (picocyanobacteria, picoeukaryotes, and nanophytoplankton) were identified by cytometry using pigment fluorescence and light scatter characteristics. The picocyanobacteria and picoeukaryotes had significantly higher cell viability than the nanophytoplankton population at all depths throughout the study area. Viability correlated positively with the photosynthetic efficiency (Fv/Fm, maximum quantum yield of photosystem II) as measured on the total phytoplankton community. However, an anticipated correlation with dissolved organic carbon was not observed. We found that the abiotic factors suggested to affect phytoplankton viability in other marine ecosystems were not as important in the Baltic Sea, and other biotic processes, e.g. processes related to species succession could have a more pronounced role.peerReviewe

A 3-Approximation Algorithm for Maximum Independent Set of Rectangles

We study the Maximum Independent Set of Rectangles (MISR) problem, where we are given a set of axis-parallel rectangles in the plane and the goal is to select a subset of non-overlapping rectangles of maximum cardinality. In a recent breakthrough, Mitchell [2021] obtained the first constant-factor approximation algorithm for MISR. His algorithm achieves an approximation ratio of 10 and it is based on a dynamic program that intuitively recursively partitions the input plane into special polygons called corner-clipped rectangles, without intersecting certain special horizontal line segments called fences. In this paper, we present a 3-approximation algorithm for MISR which is based on a similar recursive partitioning scheme. First, we use a partition into a more general class of axis-parallel polygons with constant complexity each, which allows us to provide an arguably simpler analysis and at the same time already improves the approximation ratio to 6. Then, using a more elaborate charging scheme and a recursive partitioning into general axis-parallel polygons with constant complexity, we improve our approximation ratio to 3. In particular, our partitioning uses more general fences that can be sequences of up to O(1) line segments each. This and our other new ideas may be useful for future work towards a PTAS for MISR.Comment: 41 page

Erfaringer fra utviklingen av undervisningsmetoder for studentaktiv og fleksibel stedsuavhengig læring på et heldigitalt årstudium

Læringsfestivalen 2024, Trondheim 27. mai - 28. mai 2024.Arrangør: NTNUpublishedVersio

Publisher Correction: Identification and characterization of the novel colonization factor CS30 based on whole genome sequencing in enterotoxigenic Escherichia coli (ETEC).

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper

Identification and characterization of the novel colonization factor CS30 based on whole genome sequencing in enterotoxigenic Escherichia coli (ETEC).

The ability to colonize the small intestine is essential for enterotoxigenic Escherichia coli (ETEC) to cause diarrhea. Although 22 antigenically different colonization factors (CFs) have been identified and characterized in ETEC at least 30% of clinical ETEC isolates lack known CFs. Ninety-four whole genome sequenced "CF negative" isolates were searched for novel CFs using a reverse genetics approach followed by phenotypic analyses. We identified a novel CF, CS30, encoded by a set of seven genes, csmA-G, related to the human CF operon CS18 and the porcine CF operon 987P (F6). CS30 was shown to be thermo-regulated, expressed at 37 °C, but not at 20 °C, by SDS-page and mass spectrometry analyses as well as electron microscopy imaging. Bacteria expressing CS30 were also shown to bind to differentiated human intestinal Caco-2 cells. The genes encoding CS30 were located on a plasmid (E873p3) together with the genes encoding LT and STp. PCR screening of ETEC isolates revealed that 8.6% (n = 13) of "CF negative" (n = 152) and 19.4% (n = 13) of "CF negative" LT + STp (n = 67) expressing isolates analyzed harbored CS30. Hence, we conclude that CS30 is common among "CF negative" LT + STp isolates and is associated with ETEC that cause diarrhea

Gröna tak för biologisk mångfald

Gröna tak kan utgöra livsmiljö för många växter och djur om man anlägger taken med detta syfte. I detta Movium Fakta presenteras erfarenheter och resultat från BiodiverCity samt andra relaterade projekt med målsättningen att bidra till ökad kunskap om den potential ett grönt tak kan ha för att främja den biologiska mångfalden