hh.sePublications
Change search
Refine search result
1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Engdahl, Sheila
    et al.
    University of Gothenburg, Gothenburg, Sweden.
    Aronsson, Henrik
    University of Gothenburg, Gothenburg, Sweden.
    Sundqvist, Christer
    University of Gothenburg, Gothenburg, Sweden.
    Timko, Michael P.
    University of Virginia, Charlottesville, USA.
    Dahlin, Clas
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Association of the NADPH: protochlorophyllide oxidoreductase (POR) with isolated etioplast inner membranes from wheat2001In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 27, no 4, p. 297-304Article in journal (Refereed)
    Abstract [en]

    Membrane association of NADPH:protochlorophyllide oxidoreductase (POR, EC: 1.6.99.1) with isolated prolamellar bodies (PLBs) and prothylakoids (PTs) from wheat etioplasts was investigated. in vitro-expressed radiolabelled POR, with or without transit peptide, was used to characterize membrane association conditions. Proper association of POR with PLBs and PTs did not require the presequence, whereas NADPH and hydrolysable ATP were vital for the process. After treating the membranes with thermolysin, sodium hydroxide or carbonate, a firm attachment of the POR protein to the membrane was found. Although the PLBs and PTs differ significantly in their relative amount of POR in vivo, no major differences in POR association capacity could be observed between the two membrane systems when exogenous NADPH was added, Experiments run with only an endogenous NADPH source almost abolished association of POR with both PLBs and PTs. In addition, POR protein carrying a mutation in the putative nucleotide-binding site (ALA06) was unable to bind to the inner membranes in the presence of NADPH, which further demonstrates that the co-factor is essential for proper membrane association. POR protein carrying a mutation in the substrate-binding site (ALA24) showed less binding to the membranes as compared to the wild type. The results presented here introduce studies of a novel area of protein-membrane interaction, namely the association of proteins with a paracrystalline membrane structure, the PLB.

  • 2.
    Koch, Kamilla
    et al.
    University of Mainz.
    Quast, Malte
    Waldweg 8, 38176, Wendeburg, Germany.
    Sahlén, Göran
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Morphological differences in the ovary of Libellulidae (Odonata)2009In: International Journal of Odonatology, ISSN 1388-7890, Vol. 12, no 1, p. 147-156Article in journal (Refereed)
    Abstract [en]

    All female Odonata have been assumed to produce oocytes continuously during their mature life span. However, a recent study of ovariole orientation and development led to the suggestion that Libellulidae are divided into two groups of species, one with continuous, the other with stepwise oocyte production. To find more evidence of this division, we compared the size variation and growth within the vitellarium of the ovary, studying oocytes, and follicle cells. We found that morphological characters discriminate between the two ovary types in eight of the 10 investigated species. In both types we found an increase in all measurements from the anterior to the posterior end of the vitellarium. The increase in oocyte width and follicle cell length was significantly higher in species with a continuous oocyte production. We also noted that follicle cells may have more than one nucleus and that their number can vary during vitellogenesis. Our study confirmed the hypotheses that two different ovary types exist in Libellulidae. The two species not fitting into this grouping could be an artefact of small samp le size due to intraspecific phenotypic plasticity, or else there might be more than two ovary groups, or even a continuum. We could not offer an explanation as to how the process of stepwise oocyte production differs from continuous based production on morphological characters.

  • 3.
    Lind, Linus
    Halmstad University, School of Business and Engineering (SET).
    Typhas inverkan på reningsgraden av TKN, BOD5 och COD i en anlagd rotzonsvåtmark i pilotskala.2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The ability for a subsurface flow constructed wetland system to treat landfill leachate was evaluated in Lajeado, Rio Grande do Sul, Brazil. Eight 0.95 m x 0.6 m experimental (SSF) units with a depth 0.4 m were used. Each wetland had unique conditions. Four units were planted with Typha angustifolia L. and four units were unplanted. Two different substrate dimension were used, four units with sand and four with gravel. Four wetlands operated in batch mode and four units with continuous flow. Batch flow systems were drained and filled up each week. To review vegetations impact on BOD5, COD and nitrogen compounds reduced in a wetland. This project lasted between January until May 2010 and samples were analyzed in April to May in four weeks.The result from this project show higher evapotranspiration water loss in units with planted vegetation and higher effluents concentration of BOD5, COD and nitrogen compounds, than in unplanted units.The ability for a subsurface flow constructed wetland system to treat landfill leachate was evaluated in Lajeado, Rio Grande do Sul, Brazil. Eight 0.95 m x 0.6 m experimental (SSF) units with a depth 0.4 m were used. Each wetland had unique conditions. Four units were planted with Typha angustifolia L. and four units were unplanted. Two different substrate dimension were used, four units with sand and four with gravel. Four wetlands operated in batch mode and four units with continuous flow. Batch flow systems were drained and filled up each week. To review vegetations impact on BOD5, COD and nitrogen compounds reduced in a wetland. This project lasted between January until May 2010 and samples were analyzed in April to May in four weeks.The result from this project show higher evapotranspiration water loss in units with planted vegetation and higher effluents concentration of BOD5, COD and nitrogen compounds, than in unplanted units.

  • 4.
    Persson, Linnéa
    Halmstad University, School of Business, Engineering and Science.
    Skyddsvärda kärlväxter i Haväng och Vitemölla strandbackar: – utbredning, hot och skötsel2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Semi-natural grasslands are one of the most threatened habitats in Scandinavia. The grassland in this study is situated in the northern part of the nature preserve of Haväng och Vitemölla strandbackar in the province of Skåne and consists of grey dunes and a pasture which partly consists of calcareous grassland and the vegetation type sand steppe which is very rare in Sweden. There are several threatened plants in the area and during the summer of 2017 their distribution was registered to be able to protect them during conservation management. The results showed that most of the area contained important species and the most important areas to protect were the sand steppe areas. This is probably due to the dry, sandy, calcareous and nutrient poor conditions in these areas which many of the threatened plants are connected to. Most of the threatened plants were found in abundance in the area but have a limited distribution in Sweden. The population of Eryngium maritimum however was very small and is threatened by extinction. The plants in the area are threatened by a long-term process of nutrient enrichment and continuous leakage of calcium which may lead to lower pH and a more nutrient rich soil which leads to a higher availability of phosphorous. This may lead to a change in species composition and loss of species richness. Continuous grazing, soil disturbance to expose lime-rich sand and also removal of litter to minimize the nutrient levels are needed to maintain favorable conditions in the area. However, the number of important species requires attention and careful planning, especially in the sand steppe areas. 

  • 5.
    Renner, Samuel
    et al.
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brasil.
    Périco, Eduardo
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brasil.
    Sahlén, Göran
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Man-made lakes form species-rich dragonfly communities in the Brazilian Atlantic Forest (Odonata)2016In: Odonatologica, ISSN 0375-0183, Vol. 45, no 3-4, p. 135-154Article in journal (Refereed)
    Abstract [en]

    One of the forest types occurring in Southern Brazil is the Mixed Ombrophilous Forest (MOF), a subtype of the Atlantic Forest and one of the biodiversity hotspots on Earth. We sampled adult Odonata at 30 locations in the Floresta Nacional de São Francisco de Paula (FLONA-SFP), Rio Grande do Sul, Brazil, a national reserve which is divided into several sectors of MOF, planted Araucaria angustifolia, Pinus elliottii used for sustainable and financial purposes, and open fields. There are three types of aquatic environments in the reserve: lakes, swamps, and rivers/streams. Our aim was to obtain an overview of the species’ distribution patterns in the three types of aquatic environments and to evaluate the species occurring in lakes, an exclusively man-made habitat in this area. We recorded 46 species from seven odonate families; 25 species (x = 5.71 ± 1.77 SD) occurring in rivers/ streams, 24 in lakes (11.57 ± 2.15) and 21 in swamps (5.22 ± 3.60). Using Non-metric Multidimensional Scaling (NmDS), we showed that the species composition differed clearly between the three types of aquatic habitats. While swamps and rivers/streams had a relatively similar and uniform species composition, species in the lakes were more varied but the total species number was almost as high as that of the rivers/streams. The lake communities also differed distinctly from those of the other habitats, and we assume that the lake species originate from other degraded areas in the vicinity, indicating that the remains of the Atlantic Forest has already been strongly altered by humans. Given the poor knowledge of the Odonata in the Atlantic Forest/MOF, we hope that our study may increase the understanding of the communities, and contribute to the development of conservation measures for this fragmented biome.

  • 6.
    Schjoerring, Jan K.
    et al.
    Plant Nutrition Laboratory, Roy. Vet. and Agric. University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
    Husted, Søren
    Plant Nutrition Laboratory, Roy. Vet. and Agric. University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
    Mäck, Gisela
    Plant Nutrition Laboratory, Roy. Vet. and Agric. University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
    Mattsson, Marie
    Plant Nutrition Laboratory, Roy. Vet. and Agric. University, Denmark.
    The regulation of ammonium translocation in plants2002In: Journal of Experimental Botany, ISSN 0022-0957, E-ISSN 1460-2431, Vol. 53, no 370, p. 883-890Article in journal (Refereed)
    Abstract [en]

    Much controversy exists about whether or not NH+4 is translocated in the xylem from roots to shoots. In this paper it is shown that such translocation can indeed take place, but that interference from other metabolites such as amino acids and amines may give rise to large uncertainties about the magnitude of xylem NH+4 concentrations. Elimination of interference requires sample stabilization by, for instance, formic acid or methanol. Subsequent quantification of NH+4 should be done by the OPA-fluorometric method at neutral pH with 2-mercaptoethanol as the reducing agent since this method is sensitive and reliable. Colorimetric methods based on the Berthelot reaction should never be used, as they are prone to give erroneous results. Significant concentrations of NH+4, exceeding 1 mM, were measured in both xylem sap and leaf apoplastic solution of oilseed rape and tomato plants growing with NO-3 as the sole N source. When NO-3 was replaced by NH+4, xylem sap NH+4 concentrations increased with increasing external concentrations and with time of exposure to NH+4. Up to 11% of the translocated N was constituted by NH+4. Glutamine synthetase (GS) incorporates NH+4 into glutamine, but root GS activity and expression were repressed when high levels of NH+4 were supplied. Ammonium concentrations measured in xylem sap sampled just above the stem base were highly correlated with NH+4 concentrations in apoplastic solution from the leaves. Young leaves tended to have higher apoplastic NH+4 concentrations than older non-senescing leaves. The flux of NH+4 (concentration multiplied by transpirational water flow) increased with temperature despite a decline in xylem NH+4 concentration. Retrieval of leaf apoplastic NH+4 involves both high and low affinity transporters in the plasma membrane of mesophyll cells. Current knowledge about these transporters and their regulation is discussed.

  • 7.
    Sjövall, Anna
    Halmstad University, School of Business, Engineering and Science.
    Inventering av kärlväxter i Vapnö grustäkt2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nitrogen deposition and changes in agriculture and forestry have led to a decrease of sandy habitats in Sweden due to regrowth of vegetation. Sand- and gravelpits can act as refuges for vascular plants that require the dry and nutrient-poor conditions of sandy soils. Vapnö gravelpit in Halland county in Sweden was surveyed in 2010 and proved to hold a high biodiversity including 145 species of vascular plants, of which four were red-listed. Now, seven years later, the purpose of this study was to see how the composition of vascular plants has changed since then. The area was studied on ten occasions from April to August, and all species of vascular plants were noted. The study resulted in a list of 224 species, of which 63 were remaining since 2010 and 161 were new species for the area. There were five red-listed species: Dianthus armeria (EN), Genista pilosa (NT), Thymus serpyllum (NT), Ulmus glabra (CR) and Acer campestre (CR). The total number of species and red-listed species have increased, suggesting a positive development of the biodiversity of the area. The high species diversity is probably due to the open, varied landscape and the presence of the red-listed species due to the increasingly rare sandy habitat. The diversity of vascular plants in the area is threatened by regrowth of vegetation, as well as the invasive species Lupinus polyphyllus and Fallopia japonica. These threats can be counteracted by disturbance in the form of mowing or digging up plants, prescribed burning or grazing.

  • 8.
    Strand, John A.
    et al.
    The Rural Economy and Agricultural Society of Halland, Lilla Boslid, Eldsberga, Sweden .
    Weisner, Stefan E.B.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Phenotypic plasticity – contrasting species-specific traits induced by identical environmental constraints2004In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 163, no 3, p. 449-451Article in journal (Refereed)
    Abstract [en]

    Can it be assumed that a specific environmental constraint imposed on different species leads to a convergence in, for example, morphology? A phenotype expressed in response to external stimuli (e.g. size-reduction in response to mechanical stress) should be adaptive regardless of species – this is largely intuitive, but has been poorly studied. In this issue (pp. 651–660), Puijalon & Bornette reveal exciting new data that suggest that phenotypic plastic responses to identical environmental constraints may indeed be species-specific (Puijalon & Bornette, 2004).

  • 9.
    Suhling, Ida
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). Technische Universität Braunschweig, Braunschweig, Germany.
    Suhling, Frank
    Technische Universität Braunschweig, Braunschweig, Germany.
    Thermal adaptation affects interactions between a range-expanding and a native odonate species2013In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 58, no 4, p. 705-714Article in journal (Refereed)
    Abstract [en]

    1.Increasing temperature and invading species may interact in their effects on communities. In this study, we investigated how rising temperatures alter larval interactions between a naturally range-expanding dragonfly, Crocothemis erythraea, and a native northern European species, Leucorrhinia dubia. Initial studies revealed that C.erythraea grow up to 3.5 times faster than L.dubia at temperatures above 16 degrees C. As a result, we hypothesised that divergent temperature responses would lead to rapid size differences between coexisting larvae and, consequently, to asymmetric intraguild predation at higher ambient temperatures. 2. Mortality and growth rates were measured in interaction treatments (with both species present) and non-interaction controls (one species present) at four different temperature regimes: at an ambient temperature representative of central Germany, where both species overlap in distribution, and at temperatures increased by 2, 4 and 6 degrees C. 3.The mortality of C.erythraea did not differ between treatment and control. In contrast, mortality of L.dubia remained similar over all temperatures in the controls, but increased with temperature in the presence of the other species and was significantly higher there than in the controls. We concluded that L.dubia suffered asymmetric intraguild predation, particularly at increased temperature. Reduced growth rate of L.dubia in the interaction treatment at higher temperatures also suggested asymmetric competition for prey in the first phase of the experiment. 4.The results imply that the range expansion of C.erythraea may cause reduction in population size of syntopic L.dubia when temperature rises by more than 2 degrees C. The consequences for future range patterns, as well as other factors that may influence the interaction in nature, are discussed. © 2013 Blackwell Publishing Ltd.

  • 10.
    törnqvist, sofia
    Halmstad University, School of Business, Engineering and Science.
    Skötsel av tätortsnära natur: Skötselplan för Ollonstupet2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The urban areas in the world continues to increase, cities becomes denser at the same time as they’re expanding. The nature found in the urban environments is important, both for its biodiversity and the services it provides for humans. To preserve and promote green spaces in the city is important. This is done largely by incorporating the urban nature in politics and city-planning. It is also done by more practical managementmeasures in the field, which are favourable for the urban nature. These measures vary depending on the nature values you want to promote and preserve. In Borås municipality the park management is responsible for the management of the municipality's natural areas. However, there are a lack of guidance and advice on how some of these areas can be managed. The aim of this work has therefore been to developa management plan for one of these urban nature areas. The area in question;Ollonstupet, is one of the most highly classified nature areas in the city of Borås. Various management measures, targets and guidelines are proposed, based on the nature- and recreational-values in the area. The basis for the management plan has been developed through field work, as well as previous inventories and assessments of biodiversity values.

  • 11.
    Waara, Sylvia
    et al.
    Department of Physiological Botany, University of Uppsala, Uppsala, Sweden.
    Pijnacker, Laas P.
    Rijksuniversiteit Groningen, Department of Genetics, Groningen, Netherlands.
    Ferwerda, Margriet A.
    Rijksuniversiteit Groningen, Department of Genetics, Groningen, Netherlands.
    Wallin, Anita
    Uppsala Universitet, Department of Physiological Botany, Uppsala, Sweden.
    Eriksson, Tage
    Uppsala Universitet, Department of Physiological Botany, Uppsala, Sweden.
    A cytogenetic and phenotypic characterization of somatic hybrid plants obtained after fusion of two different dihaploid clones of potato (Solatium tuberosum L.)1992In: Theoretical and Applied Genetics, ISSN 0040-5752, E-ISSN 1432-2242, Vol. 85, no 4, p. 470-479Article in journal (Refereed)
    Abstract [en]

    Somatic hybrid plants of various ploidy levels obtained after chemical fusion between two dihaploid clones of potato Solanum tuberosum L. have been analysed by cytological, morphological and molecular methods. The hybrid nature of tetraploid and hexaploid plants and the genome dosage in hexaploid hybrids were confirmed by Giemsa C-banding. Tetraploid and hexaploid hybrids showed numerical as well as structural chromosome mutations. The latter occurred mainly in the nuclear organizing chromosome. The tetraploid hybrids were more vigorous than the dihaploid parents as demonstrated by an increase in height, enlargement of leaves, increase in the number of internodes, restored potential for flowering and increased tuber yield. The grouping of tetraploid somatic hybrids into various classes on the basis of leaf morphology revealed that plants with a full chromosome complement were more uniform than aneuploids. Many hexaploid somatic hybrids were also more vigorous than the dihaploidparents and could be grouped into two different classes on the basis of floral colour and tuber characteristics, the differences being due to their different dosage of parental genomes. Most of the tetraploid somatic hybrids showed pollen development halted at the tetrad stage as one of the parental clones contained a S. Stoloniferum cytoplasm. However, one tetraploid plant produced pollen grains with high viability. The chloroplast genome in the hybrid plants was determined by RFLP analysis. All of the hybrids had a cpDNA pattern identical to one parent, which contained either S. Tuberosum or S. Stoloniferum cpDNA. A slight preference for S. Tuberosum plastids were observed in hybrid plants. No correlation between pollen development and plastid type could be detected. © 1992 Springer-Verlag.

  • 12.
    Waara, Sylvia
    et al.
    Department of Physiological Botany, Uppsala University, Uppsala, Sweden.
    Wallin, Anita
    Department of Physiological Botany, Uppsala University, Uppsala, Sweden.
    Eriksson, Tage
    Department of Physiological Botany, Uppsala University, Uppsala, Sweden.
    Production and analysis of intraspecific somatic hybrids of potato (Solanum tuberosum L.)1991In: Plant Science, ISSN 0168-9452, Vol. 75, no 1, p. 107-115Article in journal (Refereed)
    Abstract [en]

    Photoplasts of two dihaploid lines of potato were fused to produce a large number of intraspecific somatic hybrid plants among which plants of the expected tetraploid level might be found. Fusion frequencies up to 12% (mean 7%) were observed using a revised polyethylene glycol fusion protocol. Fusion products were identified by the dual fluorescence emission from the chloroplasts in mesophyll protoplasts (red) and from the fluorescein diacetate stain in light and norflurazon bleached protoplasts (yellow-green). Hybrid cells were isolated 2–3 days after fusion and cultured at a cell density of 2000 cells/ml. From a total of 1363 isolated putative hybrid cells, 258 divided to form calli. Plants were regenerated from 166 of these. Isozyme analysis confirmed the hybrid nature in 57 of 58 analysed plants. Ploidy was determined in 51 plants; 12% were tetraploid, 41% hexaploid, 12% octoploid and 35% were mixoploid. Expression of isocitrate dehydrogenase isozymes indicated that the majority of the hexaploid hybrids contained 2 genomes of the bleached parent and one genome of the mesophyll parent. This study shows that tetraploid somatic hybrid potato plants can be obtained by the fusion and selection method presented.

1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf